Materia Medica

Also: acai berry, acai palm

The dark purple fruit of an Amazon palm, sold in the United States for weight loss, energy and aging skin. Very little research has been done in people, and there is not enough reliable information to say whether it helps with anything.

Also: Barbados cherry, West Indian cherry, acerola cherry, cereza

A small, sour red cherry from the Caribbean and tropical Americas, among the richest natural sources of vitamin C. It is sold as a powder and in vitamin C supplements. One small study in people suggests the vitamin C in acerola juice is absorbed somewhat better than plain vitamin C; its other promoted effects rest on lab research.

Also: calabash nutmeg, Monodora

The seed of a West African tree, used whole or ground as a spice. No study has tested it in people; the evidence is market testing, which found lead in samples from Nigeria and aflatoxins in powder from Ghana.

Also: magic muthi, yellow stars, star lily, Afrika-patat

The underground corm of a yellow-flowered southern African plant, widely sold as an immune tonic, including to people living with HIV. There are no trials showing it works, one trial was stopped over apparent bone-marrow suppression, and wild plants are under pressure from harvesting.

Also: Rauwolfia vomitoria, asofeyeye (Lagos), akata (Benin), ira (Lagos)

A West and Central African shrub whose root is a widely used traditional sedative and blood pressure remedy. The root bark contains reserpine, a prescription drug with real side effects. The plant itself has not been studied on its own in people.

Also: Artemisia afra

An aromatic African shrub and one of South Africa's most used herbal remedies, taken as a tea for coughs, colds, flu and malaria. Lab tests show only weak activity, the two large trials of it were retracted, and WHO does not support any Artemisia plant material for malaria.

Also: aloeswood, lign-aloes, eaglewood, oud

A dark, fragrant resin that forms in the heartwood of Aquilaria trees of South and Southeast Asia, burned as incense and prized as one of the costliest perfumes in the world. It is the "aloes" of the Bible's perfume verses. It has not been studied in people.

Also: cockleburr, stickwort, Agrimoniae herba

A roadside plant with spikes of small yellow flowers and burs that cling to clothing, long drunk as a mildly astringent tea. Two small studies in people have looked at it, one of them a placebo-controlled trial in adults with raised liver enzymes.

Also: ajowan, carom seed, bishop's weed, omum

Small, thyme-scented seeds used in Indian breads, snacks and pickles, and the household spoonful for indigestion. Small trials of an ajwain skin cream for nerve pain point in opposite directions.

Also: akuamma seed, Picralima klaineana, ebam (the wood, in trade)

The intensely bitter seeds of a West and Central African forest tree, taken there for fever, malaria and pain. Its alkaloids act on the body's opioid receptors in the laboratory, and the seeds are now sold online in the US as a pain remedy. It has not been properly studied in people.

Also: alfalfa sprouts, Medicago sativa

A plant eaten as sprouts and sold as leaf and seed supplements. It is promoted to increase breast milk, with no valid trials behind that, and its human research is thin.

Also: pimento, pimenta, Jamaica pepper, Jamaican pepper

The dried unripe berry of a Caribbean evergreen tree, named allspice because it tastes like several spices at once. It is mainly a food spice; the medicinal properties claimed for it come from lab and animal studies, not trials in people.

Also: aloe, Barbadoes aloes, Curaçao aloes

A succulent whose inner-leaf gel is used on the skin and whose bitter outer-leaf juice (latex) was once a laxative. Small studies suggest the gel on the skin may help burns and acne; taking aloe by mouth carries real safety concerns.

Also: ginseng, North American ginseng, Wisconsin ginseng, Aralia quinquefolia

The root of a woodland plant of eastern North America, a close relative of Asian ginseng, sold for colds, fatigue and blood sugar. A handful of trials in people found small effects on colds, cancer-related fatigue and blood sugar; it can weaken the blood thinner warfarin.

Also: mayapple, may apple, wild mandrake, Indian apple

The root of the mayapple, a woodland plant of eastern North America and a powerful purge in 19th-century medicine. It is poisonous: its resin, podophyllin, has caused severe poisonings and deaths. A purified compound from it, podophyllotoxin, has replaced the resin for genital warts.

Also: amalaka, emblic myrobalan, Emblica officinalis, ánvula

The sour green fruit of an Indian tree, eaten fresh, pickled and dried, and one of the three fruits of triphala. Small trials suggest it may improve cholesterol and blood sugar numbers; reviewers say the results need confirming.

Also: garden angelica, Archangelica officinalis, Angelica officinalis

A tall, aromatic garden plant of northern Europe whose root, seed and preserved stems have long been used as medicine and food. Leaf extracts have been tried for night-time and overactive bladder in two small trials, with mixed results.

Also: aniseed, green anise, sweet cumin, anis

The sweet, licorice-scented seed of a small plant in the carrot family, used in breads, sweets and drinks. European regulators accept aniseed tea for mild bloating and for coughs with a cold on long use alone; a few small trials in people exist, and the essential oil is far stronger than the seed.

Also: achiote, achiotl, urucu, roucou

The red seed coating of a tropical American shrub, used as a spice and food color in Latin American and Caribbean cooking and to color cheese, butter and snacks worldwide. Studies in people are few; rare, sometimes severe allergic reactions are its main known risk.

Also: arjun, kahu, kukubha, shárdul

The bark of a large Indian tree, used in Ayurveda for the heart for centuries and sold today for heart health. Trials are few and mostly weak: evidence for angina is insufficient, and for heart failure it is mixed.

Also: leopard's bane, arnica flower

A yellow mountain daisy sold mainly as a gel, cream or ointment for bruises, sprains and sore muscles. It is used on unbroken skin only: taken by mouth, the plant itself is poisonous.

Also: black chokeberry, chokeberry, aronia berry

A tart, astringent dark berry from a North American shrub, sold as juice and as a dried powder. It is very rich in plant pigments (anthocyanins). Trials have tested it for heart and metabolic health, and a 2025 review of ten of them found no clear benefit.

Also: globe artichoke, artichoke, Cynara scolymus, Cynarae folium

The bitter leaves of the globe artichoke plant, taken as tea or extract. EU regulators accept it for indigestion and bloating on long tradition, and pooled trials of artichoke extracts show modest drops in cholesterol.

Also: hing, hingu, asafetida, devil's dung

The strong-smelling dried resin of a giant fennel from Iran and Afghanistan, fried in a pinch of oil at the start of countless Indian dishes. One company-funded trial found it eased indigestion; given to babies as a folk remedy, it has caused dangerous poisoning.

Also: Asoka, Asok, Jonesia Asoca, Saraca indica

A flowering tree sacred in Indian tradition whose bark is a classic Ayurvedic remedy for women's complaints. There is no study of the bark on its own in people, and most bark sold in Indian markets was found not to be ashoka at all.

Also: Indian ginseng, winter cherry

An evergreen shrub of India, Africa, and the Middle East, sold as root, leaf, or root-and-leaf extracts. Some preparations may help with sleeplessness and stress; the evidence on anxiety is unclear, and it carries more safety cautions than most herbs here.

Also: Chinese ginseng, Korean ginseng, red ginseng, white ginseng

The root of a Korean and northeastern Chinese plant, sold for stress, focus, fatigue and blood sugar. Most trials are small and short; some hint at modest effects on thinking, fatigue and erectile function, and most find no help for athletic performance.

Also: milk vetch, Huang Qi, beg kei, astragale

A root from traditional Chinese medicine, sold as an adaptogen and for colds, allergies, fatigue, kidney disease and diabetes. There is not enough reliable evidence to know whether it is useful for any health condition.

Also: brahmi, water hyssop, andri, jala-brahmi

A small creeping marsh plant of India, sold for memory and focus. A meta-analysis of nine trials found small improvements in speed of attention; it has not been shown to help any disease.

Also: bel, bilva, vilva, wood apple

The hard-shelled wood apple of India, whose leaves are offered to Shiva and whose unripe fruit is Ayurveda's classic remedy for loose bowels. The one trial of bael alone, in dysentery, found no benefit.

Also: huangqin, huang qin, Chinese skullcap, ogon

The bitter yellow root of a blue-flowered skullcap of northern China and Siberia, one of the most used herbs in Chinese and Japanese Kampo formulas. It is the herb most often linked to liver injury from Kampo medicines, and it has not been tested alone for benefit.

Also: country mallow, flannel weed, khareti, berela

A small, velvety mallow whose root is a classic Ayurvedic strengthening herb. It contains ephedrine, the stimulant behind the U.S. ban on ephedra supplements, and what is sold as bala in Indian markets is often another plant.

Also: poplar buds, balsam poplar, Balm of Gilead buds, tacamahac

The sticky, sweet-smelling spring buds of balsam poplar trees, steeped in oil or lard to make a salve. Despite the name, it is not the balm of Gilead of the Bible. It has not been studied in people.

Also: monkey bread, kuka (Hausa)

The dry, chalky pulp inside the baobab tree's fruit is a food across much of Africa and is sold elsewhere as a powder for drinks and porridge. Its research is mostly about what it contains; studies in people are few and small.

Also: berberis, Epine vinette

A spiny shrub with sour red berries and a bright yellow root bark rich in berberine. Small trials suggest barberry may modestly improve blood pressure, cholesterol, blood sugar and weight, but the trials are small and larger ones are needed.

Also: young barley, green barley, barley leaf, aojiru

The young green leaves of the barley plant, dried and ground into a powder for drinks. Lab studies are plentiful, but trials in people are few, small and short: a 2026 review calls the clinical evidence preliminary. In one small crossover trial, a barley-leaf drink with a snack lowered the blood sugar rise at the next meal.

Also: sweet basil, garden basil, bazil, sabza (Hindi)

The sweet basil of the kitchen, not holy basil (tulsi). A few small trials from Iran have tested basil oil on the skin for migraine and knee arthritis and a basil syrup for anxiety. Its oil is rich in estragole, which Europe's medicines agency asks makers of herbal medicines to keep low.

Also: bay laurel, sweet bay, bay tree, laurel

The dried leaf of the bay laurel tree, simmered in soups and stews and taken out before serving. A few small trials have tested it for blood sugar, cholesterol and stress. Doctors have reported a swallowed whole leaf perforating the bowel.

Also: bay leaf (Caribbean), West Indian bay, bay rum tree, bois d'Inde

A Caribbean tree related to allspice whose clove-scented leaves are brewed as a bush tea and distilled for bay oil, the scent of bay rum. Field surveys find it among the most used home remedies in Barbados and Dominica; it has not been studied in people.

Also: wax myrtle, southern wax myrtle, candleberry, waxberry

The root bark of the American wax myrtle, the shrub whose berries give bayberry candle wax. It was a staple of 19th-century American herbal practice as an astringent. It has only been studied in the lab; no study of the bark in people exists.

Also: beetroot, beet, red beet, beetroot powder

The red root vegetable, dried and ground into a powder sold for smoothies and as a sports supplement. Beets are rich in nitrate, which the body uses to make nitric oxide. Trials of beetroot juice show a small drop in systolic blood pressure in people with high blood pressure and a small gain in short, hard exercise; powders vary in how much nitrate they carry.

Also: gum benjamin, benzoin resin, Sumatra benzoin, Siam benzoin

A fragrant resin from Styrax trees, burned as incense and used in perfume and in the old pharmacy preparation tincture of benzoin. It is a documented cause of allergic skin reactions and has not been studied as a remedy in people.

Also: bhringaraja, Bhringarája, Kesarája, kesuriá

A small, weedy plant of wet ground whose leaf juice has long been rubbed on the scalp in India to darken hair and make it grow; it is a named ingredient in Ayurvedic hair oils. A small trial found lower blood pressure in men who took the leaf powder; there is no study of it on its own for hair in people.

Also: beleric myrobalan, bahera, behada, bharla

The fruit of a large Indian tree, the beleric myrobalan, and one of the three fruits of triphala. Almost all research is in the laboratory or in animals; one small human trial exists, so there is not enough evidence to know what it does in people.

Also: European bilberry, whortleberry, huckleberry, whorts

A European relative of the blueberry, sold for eyesight and circulation. It has not been clearly shown to help any health condition, and the best studies of night vision found no benefit in healthy people.

Also: birch leaf, white birch, European birch, Betulae folium

The leaves of two European birch trees, taken as a tea to make more urine and flush the urinary tract. European regulators accept it on the strength of long use; the few studies in people are too small to show whether it works.

Also: Garcinia kola

A bitter seed from West and Central Africa, chewed fresh. Small trials in people have studied it for knee arthritis pain and eye pressure, and it changed how the body handled the malaria drug quinine.

Also: bitterleaf, African leaf, Vernonia, ewuro (Yoruba, Abeokuta)

A bitter green eaten widely across West and East Africa and used at home for blood sugar and malaria. Most of its research is in the lab and in animals; in the one malaria trial, most infections were not cleared.

Also: cerasee, caraille (Trinidad), karela (Hindi), bitter gourd

A climbing vine with a warty, very bitter fruit. Known as cerasee in the Caribbean, where the leafy vine is boiled into a bitter tea; in India the fruit is cooked as karela; and extracts are sold for blood sugar. Trials in people with type 2 diabetes show small effects at most, from low-quality studies.

Also: Seville orange, sour orange, zhi shi, bigarade orange

A sour orange used in marmalade and flavorings, and sold in supplements for weight loss and sports performance, often as an ephedra replacement. It has not been clearly shown to help any health purpose, and serious heart events have been reported with products containing it.

Also: black snakeroot, macrotys, bugbane, bugwort

A North American root sold mainly for menopause symptoms. A 2023 review found extracts potentially helpful for hot flashes and overall menopause symptoms; rare cases of serious liver damage have been reported with products labeled as black cohosh.

Also: black seed, kalonji, black caraway, small fennel-flower

Small black seeds, kalonji in Indian cooking, sprinkled on breads and pressed for black seed oil. Many small trials in people suggest modest drops in cholesterol, blood sugar and blood pressure, but reviewers rate most of that evidence as low or very low quality. The oil has caused severe skin reactions.

Also: blackhaw, sloe-leaved viburnum, sloe, Viburnum prunifolium

The bark of a small tree of the eastern and southern United States, a close relative of cramp bark, used in the 1800s for menstrual cramps and in pregnancy. It has not been studied in people with modern methods.

Also: peppercorn, white pepper, maricha (Sanskrit), Ushana (Sanskrit)

The dried berry of a tropical vine and the most familiar spice on the table. Its sharp compound, piperine, is added to turmeric supplements because it raises the amount of curcumin that reaches the blood; in small studies it also raised blood levels of several prescription drugs.

Also: black walnut, eastern black walnut, walnut hull, Juglans nigra

The green-to-black outer husk of the eastern black walnut, sold dried or as a tincture, mostly for intestinal worms. It stains skin brown and has a long folk history, but it has only been studied in the lab, never in people.

Also: bramble leaf, blackberry, bramble, Rubus ulmifolius

The leaves of the common bramble, dried for herbal tea. They appear in the folk remedies of Alpine Italy and of Oman, including for blood sugar; they have not been studied in people.

Also: bladder-wrack, sea-wrack, Fucus, Fucus vesiculosus

A brown seaweed of Atlantic shores with paired air bladders, sold today mainly for weight loss and blood sugar. Small trials of its extracts found no effect on weight, blood sugar or most heart-risk markers. It contains iodine, as King's Dispensatory already noted in 1898.

Also: holy thistle, St. Benedict's thistle, Carduus benedictus, Centaurea benedicta

A very bitter, woolly southern European thistle taken as a tea before meals for appetite and indigestion, and sold in blends promoted to increase breast milk. There are no clinical studies of it for any use.

Also: blood-root, Sanguinaria, black salve, drawing salve

A spring wildflower of eastern North American woods whose root bleeds red juice. It was long used as a dye and a medicine; today it is best known as the corrosive ingredient in "black salve," which FDA links to tissue destruction.

Also: Caulophyllum, Zhu-nakada-tanga-makaⁿ

A woodland plant of eastern North America whose root the Omaha called their "great fever medicine." Today it is best known for use near childbirth, where case reports describe serious harm to newborns; it is not the same plant as black cohosh.

Also: blue flag iris, larger blue flag, water flag, liver lily

The wild blue iris of North American marshes, whose root was a strong purge in 19th-century medicine. The fresh root is irritating and was known to cause violent vomiting; it has not been studied in people.

Also: tall blue vervain, Verbena hastata

A North American verbena counted among Native American aromatic medicinal plants. Only its essential oil has been analyzed; no study has tested it in people.

Also: boldo leaf, boldus, Peumus

The leaf of a Chilean tree, drunk as a tea for indigestion in South American folk medicine. Europe recognizes it as a traditional herbal medicine for indigestion, but it has not been tested in trials, and it has been linked to liver injury.

Also: thoroughwort, Indian sage, Eupatorium

A North American wetland plant whose leaves grow joined around the stem, long taken as a bitter hot tea for colds, flu and fevers. There are no modern trials of the herb meeting current standards, and every sample tested in a 2018 study contained liver-toxic pyrrolizidine alkaloids.

Also: Indian frankincense, frankincense, Indian olibanum, salai

The gum resin of an Indian tree, also known as Indian frankincense, sold mostly for joint comfort. Most studies are small and of low quality; the best signal is for osteoarthritis pain, and it still needs larger trials.

Also: oruwo (Yoruba), eruwo (Yoruba), brimstone wood, Morinda citrifolia var. lucida

A West African tree with yellow wood and bitter roots whose leaves and bark are among the most used fever remedies in Nigeria, and whose root dyes the Asante red mourning cloth. It has not been studied in people.

Also: pineapple enzyme, pineapple

A group of protein-digesting enzymes from pineapple stem and fruit, sold for pain and swelling after surgery, sinus trouble, joint pain and sore muscles. Some studies suggest it may ease symptoms after wisdom tooth surgery; a prescription bromelain product is used by professionals on severe burns.

Also: wonder of life, wonder-of-the-world (Trinidad), Kalanchoe pinnata

A succulent native to Madagascar. It is a Caribbean yard remedy for coughs and foot wounds and a medicine in European anthroposophic practice. A few small trials exist; none is large enough to show a clear benefit.

Also: boegoe, boekoe, bookoo, buku

A fragrant South African shrub whose leaves were a popular 19th-century remedy for the bladder and kidneys. It is sold today in teas and supplements for urinary health, but no clinical trials in people have been done.

Also: alder buckthorn, frangula, glossy buckthorn, black alder

The aged bark of the European alder buckthorn, a stimulant laxative closely related to cascara. The EMA accepts it for short-term use in occasional constipation, but it has never been tested in people on its own; its effect is assumed from its chemistry and long use.

Also: Chai hu, Ch'ai-hu, Radix Bupleuri, Bupleurum root

A root from Chinese and Japanese (Kampo) medicine, almost always taken in formulas such as Sho-saiko-to. Formula studies for depression are low in quality, and Sho-saiko-to has rarely been linked to liver injury and lung inflammation.

Also: burdock, greater burdock, great burdock, gobo

The root of the big-leaved plant whose burs stick to clothing, eaten as a vegetable in Japan (gobo) and sold as a tea and extract. European regulators accept it for a few minor uses on the strength of long use; there are no controlled trials of the root in people.

Also: knee holly, kneeholm, pettigree, Ruscus

A small, stiff evergreen shrub whose underground stem is sold for heavy, tired legs from poor vein circulation and for hemorrhoid itching. One placebo-controlled trial suggests it may ease leg symptoms and swelling; European regulators call that evidence low and rely on long use.

Also: petasites, purple butterbur, butter-bur, petasitis

A large-leaved shrub whose root extract has been studied for migraine and whose leaf extract for hay fever. The plant naturally contains substances that can damage the liver and lungs, so only products processed to remove them are ever considered.

Also: Clitoria ternatea, Aparajita, Aprajita, Gokarna

A climbing pea with deep blue flowers, made into a blue drink and used as a natural food color. A few small, short studies in people have looked at blood sugar and blood fats after a meal; nothing longer-term has been studied.

Also: sweet flag, sweetflag, calamus root, sweet cane

An aromatic marsh plant whose root has been used in traditional medicine worldwide, now banned by the FDA from use in food. Its asarones cause liver cancer in rodents, and people who took calamus products to get high had prolonged vomiting.

Also: marigold, marygold, garden marigold, calendula flower

The orange garden marigold, whose flowers go into creams, ointments and mouth rinses for minor skin and mouth complaints. The EMA accepts it as a traditional herbal medicine for these uses based on long-standing use; the trials so far are small and flawed.

Also: Eschscholtzia californica

The state flower of California, sold as a calming herb for stress and poor sleep. The EMA accepts it as a traditional herbal medicine for these uses based on long-standing use, but it has only been tested in people as one ingredient of combination products, so its own effect is unknown.

Also: camu-camu, cacari, camocamo

A sour berry from an Amazonian shrub, very high in vitamin C and sold dried as a powder. Two small trials in people exist: one found less liver fat after 12 weeks of camu camu capsules, and one found lower inflammation markers in smokers who drank its juice.

Also: wild cinnamon, white canella, canella alba, Canella

The pale, peppery bark of a small Caribbean tree, sold in 18th-century apothecary shops as "Canella alba" (white canella). It is a warm aromatic spice; it has not been studied in people.

Also: Cape aloes, Aloe ferox

The bitter dried leaf juice of a South African aloe, sold as a stimulant laxative. The European Medicines Agency accepts it for short-term use in occasional constipation, for no more than a week, and rules it out in pregnancy, breastfeeding and children under 12.

Also: caraway seed, carraway, siyah-jira (Hindi), vilayati-jira

The crescent-shaped seed that flavors rye bread, sauerkraut and aquavit. European regulators accept caraway tea and oil for bloating on traditional grounds; the best evidence in people is for a combination capsule of caraway oil with peppermint oil.

Also: green cardamom, small cardamom, Malabar cardamom, ilachi (Hindi)

The green pods and fragrant seeds used in chai, coffee, curries and Nordic baking. A handful of small trials of cardamom powder suggest small changes in triglycerides and some blood markers; the evidence is thin and mixed.

Also: cascara, sacred bark, Rhamnus purshiana, Frangula purshiana

The aged bark of a North American buckthorn, a stimulant laxative for occasional constipation. The EMA accepts it for short-term use, though no controlled trials of cascara alone exist, and long or heavy use has been linked to liver injury.

Also: castor, castor bean, oil nut

The oil pressed or boiled from castor seeds, a household purge in Caribbean homes for generations and still sold as a laxative. It empties the bowels strongly; trials of it for starting labor are small and poor. The seeds themselves are poisonous.

Also: uña de gato

A woody Amazon vine sold for arthritis, viral infections and cancer. There is no conclusive evidence from studies in people that it helps with any health purpose.

Also: catmint, catnep, nep

A mint-family garden plant famous for what it does to cats, drunk by people as a tea for sleep, nerves and upset stomach. The tea itself has not been tested in people; the one real trial is of catnip oil as a mosquito repellent.

Also: cayenne pepper, chili, chilli, chillie

Dried, ground hot chili peppers, native to the Americas. Their heat comes from capsaicin. Capsicum plasters and creams are an EU-recognized use for muscle pain, and a strong prescription capsaicin patch helps some people with nerve pain. Eaten, chili is generally safe; its long-term health effects are unclear.

Also: celery, smallage, Apium

The small seed of the celery plant, a kitchen spice that is also sold in capsules for blood pressure. Small trials suggest celery preparations, especially the seed, may lower blood pressure a little, but the studies are few, small and inconsistent.

Also: chaga mushroom, Inonotus obliquus

A fungus that grows on birch trees, ground into powders and teas and sold for cancer and inflammation. No trial in people has tested it; the studies in people are case reports of serious kidney injury from its very high oxalate content.

Also: German chamomile, manzanilla

A daisy-family flower usually drunk as a tea. Its studies have been small and often mixed, so NCCIH cannot yet rate its usefulness for any condition.

Also: chanca piedra, quebra-pedra, stone breaker, gale of the wind

A small tropical weed whose seeds hang in a row under its leaves, sold across Latin America as "stone breaker" for kidney stones. A few small studies suggest a modest effect on stones; a trial for hepatitis B found no benefit.

Also: creosote bush, Larrea divaricata

Leaves of the creosote bush of the American Southwest, sold as tea, tablets and salves. LiverTox says it has not been shown to be effective for any medical condition, and it has been linked to serious liver injury, including liver failure that needed a transplant.

Also: chaste tree, vitex, monk's pepper, gattilier

The fruit of a Mediterranean shrub, sold mostly for premenstrual symptoms such as breast tenderness. Some low-to-moderate quality studies suggest it might help PMS symptoms; it may not be safe for people with hormone-sensitive conditions or in pregnancy.

Also: garden chervil, French parsley, cerfeuil, Kerbel

A delicate, faintly anise-flavored garden herb related to parsley, one of the fines herbes of French cooking. No study in people has tested it; what is known about its chemistry comes from lab work.

Also: chia, chia seeds, salba

Tiny seeds of a Mexican sage that swell into a gel in liquid, eaten in puddings, drinks and baking. They are high in fiber, protein and the plant omega-3 fat ALA. Reviews of trials find a drop in blood pressure but no effect on body weight or long-term blood sugar, from small studies.

Also: star chickweed, common chickweed, Alsine media

A small, soft garden weed eaten as a wild green and used in old herbal poultices and ointments for sore or inflamed skin. It has not been tested in people for any use.

Also: succory, wild succory, blue sailors, endive (a close relative)

A blue-flowered roadside plant whose bitter root is roasted as a coffee substitute and whose leaves are eaten as a bitter salad. Europe accepts the root for traditional use in mild digestive complaints; a few small trials in people exist.

Also: chitraka, chitrak, chitá, Ceylon leadwort

The root of a white-flowered shrub of India and Africa, used in Ayurveda for appetite, digestion and piles. It is a skin irritant, it harmed the liver and kidneys of rats and ended pregnancies in rats, and it has not been studied on its own in people.

Also: chive, rush leeks, cives, Schnittlauch

The smallest of the onions, grown for its hollow grass-like leaves and eaten as a mild onion flavor. It is a food herb; no study in people has tested it, and its reported medicinal properties come from lab work.

Also: Chlorella pyrenoidosa, green alga

A freshwater green alga pressed into tablets and powders, sold for nutrition, weight and cholesterol. A 2026 review of 24 trials found small improvements in weight, cholesterol and insulin, but rated most of the evidence very low certainty.

Also: chrysanthemum tea, Chü-hua, Kan-chü-hua, Hang-chü-hua

The dried flower of the garden chrysanthemum, used in Chinese medicine and brewed like chamomile. Almost nothing is known from studies in people about its effects; handling the plant is a well-documented cause of skin allergy.

Also: cinnamon bark, Ceylon cinnamon, true cinnamon, cassia cinnamon

The familiar spice, from the dried bark of Cinnamomum trees, sold as a supplement for blood sugar and weight loss. Research does not clearly support it for any health condition, and cassia, the common kind, can carry enough coumarin to matter in large amounts.

Also: goose-grass, goosegrass, catch-weed, clevers

A sticky, climbing hedgerow weed whose hooked bristles cling to clothing. Old herbals gave its cold infusion for the urinary tract and the skin. It has not been studied in people for any use.

Also: clove, laung (Hindi), lavanga (Sanskrit), lavang

The dried flower buds of an Indonesian tree, used whole and ground in cooking, and distilled into clove oil, an old toothache remedy. The European Medicines Agency accepts clove oil as a traditional herbal medicine for toothache and mild mouth and throat irritation. The oil is dangerous if swallowed: 5–10 ml (one or two teaspoons) has caused life-threatening poisoning in small children.

Also: cacao nibs, cacao, cocoa bean, cacao bean

Crushed pieces of roasted cacao beans, the raw material of chocolate, eaten as a bitter, crunchy snack or baking ingredient. In COSMOS, a trial of over 21,000 older adults, a cocoa flavanol extract did not significantly lower cardiovascular events, blood sugar problems or cognitive decline, though deaths from heart disease were lower. Cocoa products, nibs included, can carry cadmium and lead.

Also: coughwort, foals-foot, horse-hoof, bulls-foot

A yellow-flowered plant whose name, coughwort, says what it was used for: coughs and chest complaints, in both European and Chinese medicine. It has not been tested in trials in people, and it contains pyrrolizidine alkaloids, a family of compounds that can seriously damage the liver.

Also: knitbone, common comfrey, black root, Symphytum

A hairy, broad-leaved plant nicknamed knitbone, rubbed on as an ointment for sprains, bruises and sore joints. Several trials of comfrey root ointment suggest it eases pain, but taken by mouth it can cause severe liver injury, and the FDA advised removing oral comfrey products from the market in 2001.

Also: caterpillar fungus, aweto, zombie fungus, Cs-4

A fungus that grows out of caterpillars in the mountains of Tibet and southwest China, sold today (mostly as a lab-grown version) for energy, stamina and sexual health. Small trials found no effect on exercise performance.

Also: cilantro, coriander seed, dhanya (Hindi), dhana

One plant, two kitchen staples: the fresh leaves (cilantro) and the round, citrusy seeds. Coriander is safe as a food; research in people is thin, and allergy, including rare severe reactions, is the main caution.

Also: corn-silk, zea, stigmata maydis, maydis stigma

The fine threads of the corn ear, brewed as a tea for minor urinary complaints. No clinical trials have tested that use; a few small studies have looked at blood pressure and blood sugar.

Also: bachelor's button, blue bottle, bluebottle, cornflower petals

The bright blue wildflower of European grain fields, whose petals color tea blends. In folk medicine it was best known as an eyewash; it has not been studied in people.

Also: dog grass, quackgrass, twitch grass, witchgrass

The creeping underground stem of a common, hard-to-kill grass, brewed as a tea to increase the flow of urine. The EMA recognizes that as a traditional use. Studies in people exist but none is controlled, so whether it helps urinary complaints is not known.

Also: guelder rose, European cranberrybush, high cranberry, snowball tree

The bark of the guelder rose, named for its long use for muscle and menstrual cramps. That use has not been tested in people. The only studies in people, from Turkey, gave an extract of the plant to adults passing small kidney stones, with encouraging but unblinded results.

Also: American cranberry, bearberry

A North American bog berry, sold mostly for urinary tract infections. Cranberry products may lower the chance of repeat UTIs in women, though findings are inconsistent; cranberry is not a substitute for care when you already have a UTI.

Also: cubebs, cubeb pepper, kabab-chini, kankol (Hindi)

The small, stalked berry of a Javanese pepper vine, once a common European spice and a medicine of Arabic, Indian and European doctors. There is no research on it in people: every study found is in the laboratory or in animals.

Also: safed-jira (Hindi), jira (Sanskrit), jirana (Sanskrit), Jiraka (Sanskrit)

The warm, earthy seed behind curry powders, chili and many Middle Eastern and Mexican dishes. Small trials of cumin supplements suggest modest drops in blood sugar and triglycerides; the reviewers call for larger, better studies. As a kitchen spice it is recognized as safe.

Also: kadi patta, karuveppilai, kari bevu, karapincha

The glossy, aromatic leaves fried in oil to begin South Indian and Sri Lankan dishes. Small trials of a curry-leaf mouthwash and of the leaf powder for blood pressure have been run; neither is strong evidence yet.

Also: dama kese, damakasse, mechtale (Gamo)

An Ethiopian basil and one of the country's most-used household herbs, taken for fever and headache as a decoction, rubbed on, or burned as a smoke. It has not been studied in people.

Also: Turnera aphrodisiaca, Mexican damiana, true damiana

A fragrant Mexican shrub long sold as an aphrodisiac and today in mixed supplements for sexual desire and weight. The only studies in people tested blends, so what damiana itself does is unknown.

Also: lion's tooth, blowball, dandelion root

The common lawn weed, whose leaves are eaten as greens and whose root is sold for digestion and joint pain. Very little research exists, and there is no compelling evidence it helps any health condition.

Also: African locust bean, fermented locust bean, Parkia

A seasoning made by fermenting the seeds of the African locust bean tree, a key part of the diet in northern Ghana. No study has tested it in people; market testing in Ghana found a low level of mold toxin in samples sold there.

Also: devil's claw root, harpagophytum

A Kalahari plant whose dried side roots are sold, mostly in Europe, for joint pain and back pain. Studies suggest it may help some pain, but they have been inconsistent, and EU regulators rely on its long traditional use rather than trial results.

Also: Alaskan ginseng, Oplopanax horridus, Echinopanax horridus

A spiny shrub of Pacific Northwest forests, a cousin of ginseng, used as medicine by the Indigenous peoples of the region. It has been studied in the lab, mostly against cancer cells, but never in people.

Also: dill weed, dill seed, sowa (Hindi), suva

A feathery herb of the carrot family; the leaves (dill weed) flavor fish and pickles and the seeds are a spice. Small trials in people have looked at dill seed for cholesterol and blood sugar, period pain and labor, with mixed or preliminary results.

Also: danggui, tang kui, Tang-kuei, Angelica sinensis root

A root from traditional Chinese medicine, long called a women's herb and sold for menstrual and menopausal complaints. In the one placebo-controlled trial, it did no better than placebo for menopausal symptoms, and it can raise the effect of the blood thinner warfarin.

Also: Palmaria palmata, red seaweed

An edible red seaweed, sold dried and as a supplement. Two small trials found little benefit for cholesterol; in one, dulse bread nudged triglycerides, an inflammation marker and TSH upward.

Also: purple coneflower, coneflower, American coneflower, black sampson

A North American coneflower sold mostly for colds. Many studies have looked at colds: taking it may slightly lower the chance of catching one, and whether it shortens one is still unclear.

Also: black elderberry, European elder, common elder, elder

The dark purple berry of the European elder, sold as syrups and gummies for colds and flu. Some preliminary research suggests it may ease cold and flu symptoms; raw berries, leaves and stems are poisonous until cooked.

Also: scabwort, inula

A tall yellow-flowered plant whose aromatic, bitter root was a classic cough remedy in Europe and early America. It has not been tested on its own in people; the only trial used it in a mixed cough syrup.

Also: Siberian ginseng, eleutherococcus, Acanthopanax senticosus, Wu-chia

A shrub of the ginseng family, also called "Siberian ginseng," taken for tiredness and stress. Europe's herbal medicines committee accepts it for tiredness and weakness on the strength of long use, not trials; two controlled trials in people found no clear benefit.

Also: American wormseed, wormseed, Jerusalem oak, paico (Peru)

A strong-smelling herb cooked with beans in Mexican and Latin American kitchens, and an old worm remedy across the Americas, the Caribbean and North Africa. Its oil, oil of chenopodium, is a poison: strong teas and the oil have killed young children.

Also: ma huang, Chinese ephedra, ephedrine

A shrub (ma huang) whose stimulant compounds were once sold in weight-loss and energy supplements. The FDA banned dietary supplements containing ephedrine alkaloids in 2004 because of serious risks, including heart attack, stroke and seizure.

Also: espinheira santa, holy thorn, Monteverdia ilicifolia, Maytenus

A holly-leaved shrub of southern Brazil whose leaves are a popular South American folk remedy for indigestion and heartburn. A small preliminary trial compared it with a standard acid-reducing medicine.

Also: African pepper, Xylopia

The dried fruit of a West African tree, used as a culinary spice across Africa. No study has tested it as a medicine in people; the evidence is market testing, which found lead above the permitted limit in samples sold in Nigeria.

Also: Tasmanian blue gum, blue gum, fever tree, Eucalypti folium

The leaves of the Tasmanian blue gum, drunk as a tea or inhaled for coughs with a cold. EU regulators accept the leaf for that on long tradition. The essential oil pressed from the leaves is a different matter: it has caused seizures, mostly in children.

Also: mistletoe, misselto

A semiparasitic plant of apple, oak, pine and elm trees whose injected extracts are prescription drugs in Europe and are promoted for cancer. It is not a proven cancer therapy; the trials have major weaknesses, and the berries and leaves can cause serious harm when swallowed.

Also: evening primrose, EPO, evening primrose oil

An oil pressed from the seeds of a yellow wildflower that opens at sunset, rich in the omega-6 fat GLA and sold for eczema, PMS, breast pain and menopause. There's not enough evidence that it helps any health condition, and studies found it no better than placebo for eczema or breast pain.

Also: euphrasia, eyebright herb

A small meadow plant long used in eyewashes and compresses for sore, watery eyes. Europe's regulator declined to endorse it: its benefit is undocumented and homemade eye preparations are unsafe.

Also: sweet fennel, bitter fennel, Florence fennel, saunf

An anise-flavored plant of the carrot family whose seeds, leaves and bulb are all eaten. Fennel seed tea is an old remedy for wind and colic, including infant colic; the European Medicines Agency accepts it for adults on traditional grounds but advises against it under age 4, and trials in people are few and weak.

Also: methi, méthi, Greek hay, Greek clover

A clover-like plant whose maple-scented seeds are a common spice and one of the oldest medicinal plants still in use. Evidence for blood sugar, menstrual cramps and milk supply is weak or mixed, and it is not safe in pregnancy beyond food amounts.

Also: lemon bush, inzinziniba (isiXhosa), Lippia asperifolia

A strongly lemon-scented shrub of southern and eastern Africa whose leaves are brewed as a tea for colds, coughs and fevers. It has not been studied in people.

Also: bachelor's buttons, featherfew, European feverfew, matricaria

A daisy-flowered plant sold mostly for migraine. Some research suggests it may reduce how often migraines come and ease some symptoms, but the studies are small and the results mixed.

Also: common fig, Ficus, te'enah, tin (Arabic)

The fruit and leaf of the fig tree of the Middle East and Mediterranean. Dried figs were an official laxative and a classic poultice; fig leaf is brewed as a tea. The milky sap burns skin in sunlight.

Also: flax, linseed, flaxseed oil, flaxseed meal

The seed of the flax plant (the source of linen), eaten ground or pressed for its oil, which is rich in the omega-3 fat ALA. Research is of varying quality: one trial suggests flaxseed mucilage might help with weight, while lignan extracts and the oil don't seem to.

Also: He Shou Wu, Ho Shou Wu, Shou Wu Pian, He Shou Pian

A root from traditional Chinese medicine sold for graying hair, aging and constipation. It has not been shown to work in controlled trials, and it is a well-established cause of liver injury that is sometimes severe or fatal.

Also: tena adam (Amharic), tenadam, tselote (Gamo), Ruta bracteosa

A strong-smelling, bitter herb grown in Ethiopian home gardens, where it flavors coffee, sauces and cheese and is one of the most used household remedies. Taken in large amounts to end a pregnancy it has killed women, and its sap can burn the skin in sunlight.

Also: greater galangal, lesser galangal, galingal, galanga

The pungent rhizome of two ginger relatives, a cooking spice and an old remedy in Chinese, Arabic, Indian and European medicine. A few small trials of extracts exist, for knee pain, alertness and sexual side effects of antidepressants; none has been confirmed.

Also: garcinia, Malabar tamarind, brindle berry, HCA

A tart fruit from India and Southeast Asia whose rind contains hydroxycitric acid (HCA), sold for appetite control and weight loss. It is unclear whether it helps with weight, and several cases of liver damage have been reported in people taking garcinia products.

Also: zhizi, chih-tzu, shanzhizi, sanshishi

The orange, six-ribbed fruit of the fragrant gardenia, a yellow dye and a common ingredient of Chinese and Japanese herbal formulas. Years of taking formulas that contain it have been linked to a rare, serious disease of the veins of the colon.

Also: garlick, Allium

A kitchen bulb also sold as a supplement, mostly for cholesterol and blood pressure. A great deal of research exists; supplements may lower LDL cholesterol a little in people with high cholesterol, and the other effects studied are small or unclear.

Also: gentian root, felwort, baldmoney

An intensely bitter root from the mountains of Europe, taken before meals for appetite and indigestion. Its European use rests on long-standing tradition; clinical trials have not tested it.

Also: adrak (Hindi), ata-ile (Yoruba)

A rhizome used as a food and as a supplement. It has the most research for nausea, especially in pregnancy, though NCCIH notes that some of the studies have not been of high quality.

Also: Ginkgo biloba, maidenhair tree, fossil tree, Japanese silver apricot

Leaf extract from an ancient tree, sold mostly for memory and "brain health." It has been studied a great deal, and NCCIH says it has not been shown to be helpful for any condition studied; large trials found it did not lower the chance of dementia.

Also: goji berry, wolfberry, gouqizi, Kou-chi

A small red berry from Chinese medicine and cooking, eaten dried, as juice or as a tea. A few small trials in people exist, and it can strengthen the effect of the blood thinner warfarin.

Also: European goldenrod, woundwort, golden rod, Solidago

The flowering tops of European goldenrod, taken as a tea to increase urine in minor urinary complaints. Large uncontrolled studies reported improvement, but none had a comparison group, so the evidence is weak.

Also: golden seal, yellow root, goldenroot, yellow puccoon

A North American woodland plant with a bright yellow root, sold for colds and digestion. No rigorous studies have tested it in people, and it changes how the body handles many medicines.

Also: gold thread, mouth-root, canker-root, Coptis groenlandica

A tiny evergreen of cold northern bogs and Appalachian mountain swamps with bright yellow, thread-like roots. It was once one of the most popular American household remedies, above all as a mouthwash. It has not been studied in people.

Also: Centella, Asian pennywort, Indian pennywort, tiger grass

A creeping plant of wet tropical ground, eaten as a vegetable and sold for memory and for the veins of the legs. A meta-analysis found no clear effect on thinking; evidence for leg swelling is small. Rare liver injury has been reported.

Also: alligator pepper, melegueta pepper, Guinea grains, oburo (Yoruba)

Peppery seeds of a West African plant in the ginger family, used as a spice for centuries. Supplement extracts are now sold for weight loss; a few small trials found modest changes in energy use and belly fat.

Also: grape seed, grapeseed extract

An extract made from the seeds of wine grapes, sold mostly for cholesterol and blood pressure. Small studies suggest modest effects on some cholesterol numbers and on the lower blood pressure number; results vary between products.

Also: grapefruit peel, toronja, pamplemousse

A large, bitter-sweet citrus fruit whose dried peel is sold for teas and flavoring. The fact to know is that grapefruit, including its peel, can change how much of many common medicines reaches your blood, sometimes dangerously. The FDA requires warnings about it on some drug labels.

Also: Joe Pye weed, queen of the meadow, purple boneset, trumpet weed

The root of a tall pink-flowered meadow plant of eastern North America, named for its old use to pass kidney "gravel." It has only been studied in the lab, never in people.

Also: tea

Tea leaves dried without fermenting. As a drink it has no reported safety concerns beyond caffeine; concentrated extracts need more caution, and NCCIH says definite conclusions cannot yet be reached for most uses.

Also: guaco, Mikania laevigata, Mikania

A climbing vine of Brazil whose leaves are made into cough syrups and teas that are widely sold there. It has been tested for safety in healthy volunteers, but no trial has tested whether it helps a cough.

Also: guaraná, Paullinia cupana, Paullinia sorbilis, Brazilian cocoa

An Amazonian vine whose seeds are rich in caffeine, sold in energy drinks and in supplements for energy, focus and weight loss. It acts much like any other caffeine source; in studies it slightly sped up reaction time, and it did not ease cancer-related fatigue.

Also: guava, guayaba, guavas

The common Caribbean fruit tree, whose leaves and bark have long been boiled for loose bowels. One open-label trial in adults with acute diarrhea found a leaf decoction shortened recovery, and a small trial of a guava gel on mouth ulcers reported faster shrinking, but the research is thin and none of it is placebo-controlled.

Also: wayusa, Ilex guayusa, Amazonian holly

A holly tree of the upper Amazon whose caffeine-rich leaves are brewed like tea. It is an everyday drink of Kichwa families in Ecuador and is now sold worldwide; two small trials found short-term effects on alertness and a small rise in blood pressure.

Also: giloy, giloe, gurach, guduchi

A climbing vine of India whose stem is a staple of Ayurveda and was widely taken as an immune remedy during the COVID-19 pandemic. It has not been shown to help any condition in people, and it is a well-established cause of liver injury.

Also: guggulu, gugal, guggulipid, Indian bdellium

The gum resin of the mukul tree, known in trade as Indian bdellium, sold mostly for cholesterol. The research disagrees: a meta-analysis found lower cholesterol, while a careful US trial found LDL cholesterol went slightly up, and some people got a rash.

Also: anamu, gully root (Trinidad), mapourite (Trinidad), tipi (Brazil)

A garlic-smelling weed of the Caribbean and Latin America, sold as anamu. In Jamaica it is one of the plants cancer patients most often use, yet the only published trial in people found it no better than placebo, and a trial in people with cancer is still at the protocol stage.

Also: gumar, meshasringi, mera-singi, vákhandi

A climbing vine whose leaves, when chewed, briefly stop you tasting sweetness. It is sold for blood sugar and weight; small, uneven trials suggest lower blood sugar, but it has not been shown to work for diabetes.

Also: chebulic myrobalan, har, hara, harade

The dried fruit of an Indian tree, the chebulic myrobalan, and one of the three fruits of triphala. Human research is mostly on triphala as a whole; trials of haritaki on its own are single and small.

Also: hawthorne, harthorne, English hawthorn, Mexican hawthorn

A flowering shrub of the rose family, sold for the heart. It has been studied for heart failure with conflicting results, and the FDA has warned that some "tejocote root" products sold as Mexican hawthorn actually contain a toxic plant.

Also: hemp hearts, hempseed, hemp seed oil, hemp protein

The seeds of the hemp plant, eaten shelled as hemp hearts, pressed into a green oil or ground into protein powder. The FDA has no questions about hulled hemp seed, hemp protein and hemp seed oil as food. Two small trials found hemp protein lowered blood pressure against a milk protein and hemp seed oil eased dry, itchy skin in eczema.

Also: sorrel (Caribbean), zobo (Nigeria), bissap (Senegal), roselle

The dried red calyces of roselle make a tart drink across West Africa, the Caribbean and Latin America. The blood pressure evidence is mixed: a 2022 meta-analysis found a modest drop, while a 2021 Cochrane review found too little good evidence to judge.

Also: tulsi, tulasi, Krishna tulsi, Shyama tulsi

A sacred basil of India, grown at homes and temples and widely taken as a tea. Human studies are few, small and short; a 2017 review found them favorable for blood sugar and stress, and called for more research.

Also: honeybush tea, Cyclopia, Honigthee

A herbal tea made from native South African fynbos shrubs, drunk like its better-known neighbor rooibos. There are no human studies of the tea itself; one trial of a concentrated extract looked at skin wrinkles.

Also: Kalahari cactus, Xhoba, Bushman's hat

A leafless succulent from the Kalahari, sold for appetite control and weight loss. The only controlled study in people found no effect on weight or food intake, and it raised concerns about blood pressure and heart rate.

Also: hop, hop strobile, hop cones, lupulus

The cone-like flowers of the plant that bitters beer, sold for sleep and stress, usually mixed with valerian. Hops alone has not been tested for sleep, and small studies on menopause symptoms have not settled anything.

Also: white horehound, hoarhound, marrubium

A woolly, bitter member of the mint family, long made into cough syrups and candies. Its use for coughs, indigestion and appetite rests on tradition; a small trial found it did not lower blood sugar.

Also: epimedium, yin yang huo, barrenwort, bishop's hat

A low-growing plant of Chinese medicine (epimedium) sold mostly for sex drive and erections, and studied for bone loss after menopause. Its bone studies in people look promising but are few; its sexual-health claims have not been shown in good trials.

Also: horse-chestnut, buckeye, Spanish chestnut, aescin

A European tree whose seed extract is sold mostly for poor blood flow in the leg veins. A review of 17 studies suggests the extract can ease those symptoms. The raw seeds, bark, flowers, and leaves are toxic.

Also: common horse-tail, horsetail herb, equisetum

A jointed, silica-rich relative of the ferns, taken as a tea to increase urine flow and used on minor skin wounds. One small trial in healthy men found a mild water-pill effect; the rest of its use rests on tradition.

Also: wild hydrangea, smooth hydrangea, seven barks, Hydrangea arborescens

The root of the wild smooth hydrangea of the eastern United States, used by 19th-century American doctors to help pass small urinary stones. It has not been studied in people, and the modern lab research found is on other hydrangea species.

Also: hysop

A bushy garden herb of the mint family, used for coughs, colds and sore throats. It has not been tested for those uses in people; its concentrated essential oil has caused seizures.

Also: ibogaine (the alkaloid), Tabernanthe iboga

A Central African shrub whose root bark holds ibogaine, a powerful hallucinogen. It is sacred in the Bwiti religion of Gabon, and abroad it is sold, often illegally, as an addiction remedy. It has caused dangerous heart rhythms and deaths.

Also: ipecacuanha, Rio ipecac, Cephaelis ipecacuanha, Psychotria ipecacuanha

The root of a small plant of the Brazilian rainforest, the source of ipecac syrup, which was long kept at home to cause vomiting after a poisoning. Poison experts now advise against it, and repeated use has caused heart and muscle damage.

Also: zebapique (Trinidad), Neurolaena

An intensely bitter leaf that is one of the most used bush medicines in Trinidad and across the Caribbean and Central America, mainly for fever and colds. Its compounds are active in lab and animal studies, but no study in people was found.

Also: jambolan, black plum, Java plum, Indian blackberry

The purple summer fruit of India, whose seed powder is one of the most sold folk remedies for blood sugar. In the one controlled trial of its leaf tea in people with diabetes, blood sugar did not change.

Also: jinyinhua, jin yin hua, rendong, Jên-tung

The white-and-gold flowers of a climbing honeysuckle, one of the most used herbs in Chinese medicine for fevers and sore throats. Every trial found that includes it tests a multi-herb formula; it has not been studied alone.

Also: common jasmine, poet's jasmine, white jasmine, jessamine

The white, sweetly scented flowers of common jasmine, used in teas, perfume and folk medicine for pain and inflammation. Its perfume extract is a known skin allergen; the flower has not been studied in people.

Also: Indian spikenard, spikenard, muskroot, jatamansi

The fragrant root of a Himalayan plant, prized in Ayurvedic, Unani, Tibetan and Chinese medicine; a 2020 review notes it appears in the Ayurvedic classics and the Old Testament. One small trial has looked at it for blood pressure; almost nothing else has been studied in people, and the wild plant is critically endangered.

Also: Gynostemma, gypenosides

A climbing plant drunk as an herbal tea in China and Southeast Asia, and sold for cholesterol, blood sugar and stress. Reviews of mostly Chinese trials suggest effects on blood fats and blood sugar, but the evidence is of low certainty.

Also: balm of Gilead, balm of Judea, Arabian balsam, opobalsamum

A small, thorny myrrh-family tree of Arabia whose fragrant resin was the famous balm of ancient Judea. Scholars identify it with the Bible's balm of Gilead. It has not been studied in people.

Also: red date, Chinese date, dazao, hong zao

The red date of China, eaten fresh and dried and added to countless soups and herbal formulas; the seed of its wild, sour form is Chinese medicine's classic herb for sleep. Small trials suggest the fruit may ease constipation; the seed has been tested almost only in formulas.

Also: juniper berry, juniper oil, Juniperus communis, Juniperi aetheroleum

The small blue-black "berries" (really cones) of an evergreen shrub, best known for flavoring gin. They are taken for indigestion and to increase urine flow. EU regulators accept those uses on the basis of long use; one recent trial of juniper oil capsules for indigestion was positive.

Also: andrographis, kálmeg, Chuān Xīn Lián

A very bitter shrub of India and Southeast Asia, sold worldwide as andrographis for colds and sore throats. Many small trials suggest it may ease cough and sore throat, but their quality is poor, and it can cause serious allergic reactions.

Also: kantkari, nidigdhika, kateli, kateri

A spiny, yellow-berried nightshade of India, one of the ten roots of the Ayurvedic dashamula and a traditional cough and asthma herb in Ayurveda and Siddha. Two small trials in people with asthma found a modest short-term effect on breathing.

Also: kava kava, kava-kava, awa, ava

A South Pacific pepper-family root, drunk for thousands of years and sold today mostly for anxiety. Some research suggests it may help anxiety, but kava products have been linked to rare, sometimes fatal liver injury.

Also: brown algae, seaweed, Laminaria, Laminaria hyperborea

Large brown seaweeds eaten as food and sold as tablets for minerals, thyroid, weight and hair. Kelp is one of the richest food sources of iodine, and kelp supplements have caused thyroid problems and, in one case, arsenic poisoning.

Also: qat, chat, miraa (Kenya)

An evergreen shrub of East Africa and the Arabian Peninsula whose fresh leaves are chewed by millions for their stimulant effect. Its main active compound, cathinone, acts much like amphetamine. Regular chewing is linked in people to high blood pressure, mouth lesions and liver injury.

Also: kinkéliba, tisane kinkéliba

A West African shrub whose leaves make an everyday tea, especially in Senegal. Two small trials in people with high blood pressure found it lowered readings, and drinking it with a meal sharply cut how much iron was absorbed.

Also: kokam, amsul, bhirand, Goa butter tree

The sour purple fruit of a tree of India's Konkan and Goa coast, dried as a souring spice and made into the summer drink sol kadhi; its seed fat is kokum butter. It has not been studied in people on its own.

Also: cola nut, kola, bissy, bissy nut

The caffeine-rich seed of a West African tree, chewed for centuries and later used to flavor cola drinks. Its effects are expected to be those of its caffeine; kola itself has hardly been studied in people.

Also: Pueraria, ko, ko-fen, Pachyrhizus thunbergianus

An East Asian vine whose root is a food starch and an old Chinese remedy, sold today mainly to cut down on drinking. Small trials found it lowered drinking in heavy drinkers not seeking help, but a trial in people already in a counseling program found no added benefit.

Also: kutaki, katuki, Kaṭuká, Kaṭurohini

The intensely bitter root of a small Himalayan plant, a classic Ayurvedic remedy for fever and digestion and sold today for the liver. One small trial in the 1990s looked at it for acute viral hepatitis; there is little else in people.

Also: Ledum groenlandicum, Rhododendron groenlandicum

An evergreen shrub of northern North America whose leaves make a conifer-scented tea. It has not been studied in people, and a review warns against drinking it often because of toxic compounds in the leaves.

Also: ladies' mantle, Alchemilla, Alchymilla

A low garden plant with pleated, scalloped leaves, long used in European folk medicine for women's complaints and as an astringent. Almost all research is in the lab or in animals; the one trial in people found no clear effect.

Also: English lavender

A Mediterranean shrub used for its scent in baths, perfume, and aromatherapy, and sold as an oral supplement for anxiety. Oral lavender oil has the most study; aromatherapy evidence is unclear.

Also: balm, Melissa

A flowering shrub whose leaves yield a lemon-scented extract, sold on its own and in many blended supplements. Its safety record is reassuring, but we have found no NIH review of whether it works for the calming uses it is sold for.

Also: Aloysia triphylla, Lippia citriodora, Verbena triphylla, verveine odorante

A shrub with lemon-scented leaves, drunk as a tea for sleep, stress and digestion. EU regulators accept those uses on the basis of long use; two small trials of extracts reported better sleep scores, which is not yet enough to know.

Also: fever grass, fevergrass (Trinidad), lemon grass

A tall, lemon-scented grass brewed as a bush tea, called fevergrass in Trinidad, where it is drunk for fevers. The one careful trial found it did not help sleep or anxiety, and a study of heavy daily use raised a question about the kidneys.

Also: licorice, liquorice, sweet root, gan cao

A sweet root used as a flavoring and sold for digestive, respiratory, and energy support. No high-quality evidence clearly supports it for any condition, and its glycyrrhizin can seriously affect the heart in large amounts or with long use.

Also: guaiacum, gum guaiac, holy wood, bois saint

A slow-growing Caribbean tree with blue flowers and some of the hardest wood in the world. Its resin, guaiacum, was one of the most famous drugs of the 1500s to 1700s; it has not been studied on its own in people.

Also: lime flower, lime tree, linden flower, basswood

The dried, fragrant flowers of the linden or lime tree, a pleasant tea long drunk for colds and to settle the nerves. EU regulators accept both uses on the basis of long use; the EMA found almost no clinical research.

Also: Yamabushitake, hedgehog fungus, monkey head, bearded tooth

A white, shaggy mushroom with dangling spines, eaten as food and sold as a supplement for memory, focus and mood. A handful of small trials in people have mixed results; it has not been linked to liver injury.

Also: Indian tobacco, wild tobacco, puke weed, vomit weed

A small wild plant of eastern North America, long called "Indian tobacco" and famous in the 1800s as a vomiting agent. Its alkaloid, lobeline, was sold to help people quit smoking; a large trial found it did not help.

Also: pippali, pipal, magadhi, pippali-mul (root)

A spice made from the catkin-like fruits of an Indian pepper plant, and a staple of Ayurvedic formulas. Almost all research is in the laboratory or in animals; one small trial in people has been done, and there is not enough evidence to know what it does as a medicine.

Also: Lepidium meyenii, Peruvian maca, maca root

An Andean root in the mustard family, eaten as a food and sold as a powder for sexual function, fertility and energy. A handful of small trials exist; reviews call the evidence limited, and maca did not change men's hormone levels in a controlled trial.

Also: houpo, hou po, Hou-p'o, Magnolia obovata

The thick, aromatic bark of a Chinese magnolia, a staple of Chinese digestive formulas and today an ingredient in chewing gums and stress blends. A chewing gum with its extract reduced gum bleeding in one trial; its best-known supplement blends are mixtures.

Also: Grifola frondosa, maitake mushroom

An edible mushroom sold as an extract for immunity and alongside cancer care. Small trials in people show it changes immune measurements, in both directions, but have not shown clear health benefits.

Also: common mallow, high mallow, blue mallow, malva

Common mallow, a purple-flowered European weed whose slimy flowers and leaves are made into a soothing tea for sore throats and dry coughs. EU regulators accept that use on long tradition. A few small trials of mallow mouthwashes and a skin cream have been published.

Also: mandrake, Mandragora, duda'im (Hebrew), Mandragora autumnalis

The mandrake of the Bible and of ancient Mediterranean medicine, a low plant with a forked root and yellow fruit. Its root and leaves carry atropine-like poisons, and people still land in hospital after mistaking its leaves for greens.

Also: Indian madder, Manjishṭhá, Manjiṭ, Rubia Manjisṭa

The red root of a climbing madder, used for centuries as a dye and in Ayurveda for the skin. A small pilot trial found it shifted gut bacteria; no study in people shows a health benefit, and a 2022 review found clinical safety data lacking.

Also: sweet marjoram, Amaracus, Majorana, marwa (Indian bazaars)

Sweet marjoram, a close relative of oregano used in cooking and as a tea. A few small pilot trials of marjoram tea exist, in women with polycystic ovary syndrome and in people with Parkinson's disease; none is large enough to settle anything.

Also: marshmallow root, marsh-mallow, althaea, Althaeae radix

A soft, downy European plant whose root is rich in mucilage, a slippery gel. It is taken for an irritated mouth or throat and dry cough, and EU regulators accept that use on the basis of long use and some supportive studies.

Also: queen of the meadows, mead sweet, bridewort, goat's beard

A tall wetland plant with frothy, sweet-smelling white flowers, taken as a tea for colds and minor joint pain. It contains small amounts of salicylates, the family of compounds behind aspirin. EU acceptance rests on long use alone; almost no research in people exists.

Also: Mary thistle, St. Mary's thistle, holy thistle, Marian thistle

A tall purple-flowered thistle whose seed extract (silymarin) is sold mostly for the liver. Trials for liver diseases have been conflicting or too limited to draw conclusions, and product quality varies widely.

Also: drumstick tree, horseradish tree, ewe igbale (Yoruba)

A fast-growing tree whose leaves are cooked as a vegetable across Africa and Asia. By USDA figures, 100 g of raw leaves carries 9.4 g of protein, 185 mg of calcium and 51.7 mg of vitamin C. As a supplement, its research is mixed.

Also: Leonurus cardiaca, Cardiaca, Leonuri cardiacae herba

A bitter, square-stemmed plant of the mint family, long tied to the heart: its old Latin name is Cardiaca. In the EU it is accepted, on the basis of long use, for nervous tension and a nervous, pounding heart once a doctor has ruled out anything serious. Research in people is one small, uncontrolled study.

Also: wild wormwood, felon herb, St. John's plant, sailor's tobacco

A wormwood relative once called the "mother of herbs," sold today for anxiety, menstrual cramps, and sleep. Very little research has been done in people, its safety is unknown, and it should not be used in pregnancy.

Also: muirapuama, Ptychopetalum olacoides

A Brazilian wood sold in sexual-enhancement and "tonic" supplements. It has not been tested on its own in people; the few human studies used mixtures of several herbs, so they cannot say what muira puama itself does.

Also: great mullein, white mullein, mullin, higtaper

A tall, woolly roadside plant with a spike of yellow flowers. The flowers are drunk as a tea for a sore throat with a dry cough, a use EU regulators accept on the basis of long use; there are no clinical studies of mullein on its own.

Also: black mustard, brown mustard, Indian mustard, white mustard

The seeds of black, brown and white mustard plants, ground into a condiment and pressed for oil. Mustard is a well-known cause of food allergy, and mustard pastes left on the skin can burn it. There is almost no research on it as a medicine.

Also: myrrh gum, Commiphora myrrha, bola, mur

The fragrant gum resin of a thorny tree, burned as incense and dabbed on mouth sores. EU regulators accept a myrrh tincture for mouth ulcers and minor wounds on long tradition. An Egyptian myrrh drug for parasitic worm infections did poorly in trials.

Also: margosa, margosa oil, neem oil, nimb

A bitter Indian tree whose twigs, leaves, bark and seed oil have many traditional uses, today mostly in toothpaste, mouthrinse and skin products. Small trials of neem mouthrinse look promising. Neem oil taken by mouth has poisoned young children.

Also: nirgundi, nochi, sambhali, nishinda

A fragrant shrub of India and Southeast Asia whose leaves go into pillows, vapor baths and oils for aches and colds. No study of nirgundi alone in people could be found.

Also: pain bush (Trinidad), Indian mulberry, morinda, hog apple

A small tropical tree whose pungent fruit is sold worldwide as noni juice. Only a very small number of studies have been done in people, none has shown a benefit for any health condition, and a few people have developed serious liver injury after drinking it.

Also: nopales, nopalitos, prickly pear, prickly pear cactus

The flat green pads of the prickly pear cactus, eaten as a vegetable in Mexico and sold dried as a powder. Eating nopal with a starchy meal blunted the rise in blood sugar in a small study, and a fiber made from it eased irritable bowel symptoms in a one-week trial; a review found no effect on body weight.

Also: sanqi, sanchi, San-ch'i, Shan-ch'i

A ginseng relative from southwest China, prized in Chinese medicine for bleeding and wounds and, today, for the heart and after strokes. Chinese trials of its extracts are numerous and some are large, but most are small or at risk of bias, and it adds to the effect of aspirin on blood clotting.

Also: jaiphal (Hindi), jatiphala (Sanskrit), jādicāi (Tamil), mace

The seed of a tropical evergreen, a kitchen spice whose industry is a major part of Grenada's economy. In cooking amounts it is recognized as safe; in large amounts it is a poison, and poison centers see people who took it to get high.

Also: oat herb, green oat, wild green oat, common oat

The green stems and leaves of the oat plant, cut before the grain ripens and sold as tea or extract for stress and sleep. EU regulators accept those uses on long traditional use only; a few small trials of one extract have looked at attention and memory, with mixed results.

Also: olive leaves, olive leaf extract, oleae folium

The leaf of the olive tree, sold as tea and extract mainly for blood pressure and heart health. Reviews of small trials suggest it may lower blood pressure a little, especially in people with high blood pressure, but EU regulators call the research not rigorous.

Also: sweet orange peel, orange zest, orange rind, orange oil

The dried outer peel of the ordinary sweet orange, used in teas, baking and spice blends. The oil pressed from the peel gives orange its smell, and a few small trials found that breathing it in eased anxiety in stressful moments. The dried peel itself has been studied only in labs and animals.

Also: wild marjoram, origany, Origanum, grove marjoram

A kitchen herb, also sold as concentrated oil of oregano. Research in people is thin: one small trial of an oregano ointment on surgical wounds, one uncontrolled study of the oil for gut parasites, and case reports of allergy, skin irritation and a blood-thinner interaction.

Also: mahonia, Berberis aquifolium, Mahonia aquifolium

A holly-leaved shrub of the American West whose bitter yellow root and bark contain berberine. Today it is studied mostly as a skin cream for psoriasis, where small trials have given limited support.

Also: orris, Florentine iris, Iris florentina, Iris germanica

The dried, violet-scented rhizome of the Florentine iris, used in perfume, tooth powders and potpourri, and in herbal medicine in Persia, India and Turkey. It has not been studied as a medicine in people.

Also: osha root

A root from the Rocky Mountains, also used in Mexican folk medicine, sold mostly for colds and flu. It has not been studied in people; the research so far is lab and animal work.

Also: pawpaw, papaw, papaya leaf

The pawpaw of Caribbean yards, eaten as fruit and used green in cooking, whose leaf is now sold as an extract to raise low platelet counts. Small trials in dengue and in chemotherapy show platelet counts rising somewhat faster, but the largest trial is under an expression of concern and reviewers call for better studies.

Also: sweet pepper, red pepper powder, pimentón, Hungarian paprika

Ground dried red peppers of the mild, sweet kinds, used for color and flavor. It is the same species as cayenne but has little of the heat. The studies in people are of capsules of paprika's red pigments (xanthophylls), not the kitchen spice; they are small and mostly short. Adulterated paprika has poisoned people.

Also: garden parsley, common parsley, Carum petroselinum

A kitchen herb eaten in salads and sauces the world over, and an old diuretic in European medicine. As a food it is generally recognized as safe; the concentrated seed extract apiol, once taken in large doses to end pregnancies, has killed people.

Also: passion flower, maypop, maypops, apricot vine

A climbing vine with white and purple flowers, used as a sedative and sold today for anxiety and sleep. A small amount of research suggests it might ease anxiety and lengthen sleep a little; it has not been studied extensively.

Also: pau d'arco, red lapacho, lapacho, taheebo

The inner bark of a South American flowering tree, sold as a tea and in capsules, and promoted since the 1960s for cancer and infections. Lab studies of its compounds are extensive; studies in people are few, small and uncontrolled, and a 2009 review called the evidence insufficient.

Also: umckaloabo, umcka, kaloba, pelargonium root

A plant native to South Africa whose root extract is sold, mostly in Europe, for colds, coughs and bronchitis. Trials suggest it may ease acute bronchitis symptoms, but the evidence is low quality and doubt remains; liver problems have been reported.

Also: pennyroyal oil, European pennyroyal, American pennyroyal, poleo

A small mint used for centuries to bring on menstrual periods and end pregnancies. Its oil is highly toxic: taken by mouth it has caused liver failure and deaths, including in infants given home-brewed mint tea. There is no research showing any benefit.

Also: mint

A mint whose leaves make tea and whose concentrated oil comes in capsules. The oil has a small research base, mostly for irritable bowel syndrome; the leaf has very little.

Also: shiso, zisu, tzu-su, beefsteak plant

A mint-family herb with purple or green leaves, eaten as shiso in Japan and deulkkae in Korea and used as zisu in Chinese medicine for colds. Small trials of leaf extracts, some funded by their makers, found some benefit for digestive discomfort, hay fever and memory.

Also: lesser periwinkle, common periwinkle, creeping myrtle, Vinca minor

A trailing evergreen groundcover with blue flowers, an old European astringent herb that contains the alkaloid vincamine. The herb itself has not been studied in people; the supplement vinpocetine is a synthetic drug made from vincamine and carries an FDA pregnancy warning.

Also: physic nut, Barbados nut, purging nut, pinhão-manso (Brazil)

A hedge shrub of the tropical Americas whose oily seeds were a violent purge in Caribbean folk medicine. The seeds are poisonous: eating them causes vomiting and diarrhea, and children are the usual victims.

Also: prince's pine, umbellate wintergreen, ground holly, Chimaphila

A small evergreen of dry northern woods with glossy, toothed leaves, once official in the US Pharmacopeia as a urinary herb. It has not been studied on its own in people.

Also: ribwort plantain, common plantain, lance-leaved plantain, rib grass

A common roadside weed, not the cooking banana of the same name. Its leaf is sold in Europe as a syrup or tea for dry cough and throat irritation on the strength of long traditional use; one small recent trial of a Plantago major syrup found less cough in acute bronchitis.

Also: butterfly weed, orange milkweed, Asclepias tuberosa

The root of the orange-flowered butterfly weed, a milkweed, once a favorite 19th-century American remedy for chest colds and pleurisy. It has never been studied as a medicine. Like other milkweeds it contains cardiac glycosides, heart-active compounds; its sap has injured people's eyes.

Also: granatum

A Middle Eastern fruit tree whose juice and extracts are sold for blood pressure, heart health, and blood sugar. Studies, mostly of the juice, suggest small effects on blood pressure and blood sugar that need confirming.

Also: poppyseed, opium poppy seed, khus khus, khas khas

The tiny blue-black or white seeds of the opium poppy, baked into breads and pastries and ground into fillings. The seeds themselves carry little or no opium, but unwashed seeds can be coated with morphine and codeine. Tea brewed from them has caused dependence, poisonings and deaths, and even baked goods can make a urine drug test read positive.

Also: prekese (Twi), aridan (Nigeria), Tetrapleura thonningii

The long, four-winged, fragrant pod of a West African forest tree, simmered in soups across Ghana and Nigeria and used by Ghanaian herbalists for high blood pressure. It has not been studied in people.

Also: toothache tree, northern prickly ash, southern prickly ash, yellow wood

A spiny North American shrub, the "toothache tree", whose pungent bark and berries were a favorite of 1800s American doctors. It has not been studied in people.

Also: ispaghula, ispaghula husk, ispaghul, spogel seed

The husk of a small plantain's seed, which swells into a gel in water. It is a standard bulk-forming laxative, and trials show it lowers LDL cholesterol; FDA lets foods say its soluble fiber may lower the chance of heart disease. It must be taken with plenty of liquid.

Also: pepitas, pumpkin seeds, Kürbiskerne, semillas de calabaza

The seeds of the pumpkin, eaten roasted (pepitas), pressed into a dark green oil, and sold in capsules for urinary symptoms. European regulators accept pumpkin seed, on the strength of long use, for urinary symptoms of an enlarged prostate or an overactive bladder. In a one-year trial of 1,431 men, whole seeds did somewhat better than placebo while an extract did not.

Also: spreading hogweed, Punarnavá, Sothaghni, Svetapunarnabá

A creeping weed of the tropics whose root is a mainstay of Ayurvedic remedies for swelling, the kidneys and the liver. It has been studied in the laboratory and in animals, but no study of the herb on its own in people was found.

Also: African plum tree, African prune, African cherry, red stinkwood

The bark of an African mountain-forest tree, sold as an extract for urinary symptoms in men with an enlarged prostate. Older, short trials found a moderate improvement over placebo; the tree is threatened by over-harvesting.

Also: Surinam quassia, bitterwood, bitter ash, amargo

An intensely bitter wood from a small tropical American tree, used as a bitter tonic and, in Europe, as a head-lice rinse. Small trials of quassia gels on the skin and of quassia tincture for head lice reported good results, but none was placebo-controlled.

Also: cow clover, meadow clover, wild clover, trifolium

A meadow legume containing isoflavones that resemble estrogen, sold for women's health. Research on hot flashes, cholesterol, and bone density has not shown conclusive benefit.

Also: raspberry leaf, raspberry leaf tea, red raspberry, raspis

The leaf of the garden raspberry, drunk as a tea and widely taken late in pregnancy in the hope of an easier labor. The one good-sized trial found it did not shorten labor, and EU regulators advise against using it in pregnancy without medical supervision.

Also: New Jersey tea, redroot, wild snowball, mountain sweet

The deep-red root of New Jersey tea, a small flowering shrub of eastern North America. Eclectic physicians used it for sore throats, coughs and an enlarged spleen. It has only been studied in the lab, never in people.

Also: red sanders, red saunders, raktachandana, rakta chandan

The deep red heartwood of a tree of southern India's Eastern Ghats, used in Ayurveda for inflammation. It is not the scented sandalwood of perfume, and it has not been studied as a remedy in people.

Also: Ti-huang, Shêng-ti-huang, Shu-ti-huang, Kan-ti-huang

A root from traditional Chinese medicine, used raw, dried or steamed and usually taken in formulas with other herbs. The studies in people are of those multi-herb formulas, not of rehmannia alone, and they are of low quality.

Also: lingzhi, ling zhi, Ling-chih, Yeongji

A glossy, reddish-brown shelf mushroom prized in Chinese and Japanese tradition and sold today for energy, immunity and alongside cancer care. Small trials in people exist; none has shown a clear benefit, and it has been linked to rare cases of liver injury.

Also: arctic root, golden root, rose root, rosenroot

A cold-climate root sold for energy, mood, stress, and athletic performance. There isn't enough reliable evidence to know whether it is useful for any health purpose.

Also: red bush tea

A red herbal tea from South Africa, brewed from the needle-like leaves of Aspalathus linearis, either fermented (red) or unfermented (green). Most of its research is in cells and animals; the human studies are few, small and inconsistent.

Also: rose buds, rose petals, cabbage rose, Provence rose

The dried buds and petals of the cabbage rose and its cousins, used for tea, rosewater and as a mouth and skin rinse. EU regulators accept rose flower for mild mouth, throat and skin inflammation on long tradition, supported by one small trial.

Also: rosehip, dog rose, hip-tree, wild brier

The red fruit left after a wild rose flowers, eaten as jam, tea and powder and very rich in vitamin C. Three small trials of one rose hip powder, all supported by its maker, found less joint pain in osteoarthritis; independent, larger trials are still needed.

Also: Rosmarini folium, rosemary oil, romero (Spanish), romarin (French)

A Mediterranean kitchen herb. Europe's medicines agency accepts rosemary leaf tea for mild indigestion, and rosemary leaf or oil in baths and rubs for minor muscle and joint pain, on the strength of long use. Small trials have tested rosemary oil for hair loss and rosemary capsules for memory.

Also: hong hua, Hung-hua, Hung-lan-hua, Carthami flos

The red-orange flower of the safflower plant, a dye and a Chinese herbal drug thought to act on the blood. The studies in people that were found are of injected extracts given in Chinese hospitals; nothing is known from studies about the flower taken by mouth. It was used historically to end pregnancies.

Also: kesar (Hindi), kunkuma (Sanskrit), kāsmīrajanmā (Sanskrit), khoongoomapoo (Tamil)

The red threads (stigmas) of a cultivated crocus, used to color and flavor rice dishes, breads and sweets. Small trials of saffron capsules for low mood suggest it may help about as much as some antidepressants, but the trials are small; large doses, far beyond cooking amounts, are toxic.

Also: common sage, Spanish sage, garden sage, salvia

A Mediterranean kitchen herb sold as a supplement for menopause symptoms, memory, and cholesterol. Only a few small studies exist, and some sage contains thujone, which can be toxic in large amounts.

Also: dragon's blood, sangre de grado, sangre de drago, Croton lechleri

The blood-red sap of an Amazonian tree, painted on cuts and insect bites and taken for diarrhea in South American folk medicine. A purified drug made from it, crofelemer, is a U.S. prescription medicine for one kind of diarrhea; the sap itself has not been properly tested.

Also: Jamaican sarsaparilla, Smilax

The root of a prickly tropical vine that grows along Jamaican riverbanks. It was a celebrated remedy in the 1700s and 1800s and is still sold as a root tea and capsules, but no clinical trials of it in people were found, and it is one of the most often mislabeled herbs on the market.

Also: sassafras root bark, sassafras pith, Sassafras officinale, Sassafras variifolium

A North American tree whose aromatic root bark was a spring tonic and flavoring. The main compound in its oil is safrole, which caused liver cancer in rodents, and the FDA prohibits safrole in food. Only safrole-free sassafras extracts may be used as flavorings.

Also: Kigelia, pandoro (Yoruba), rahaina (Hausa), Kigelia pinnata

A tall shade tree of tropical Africa whose huge, hanging, sausage-shaped fruits and bark are used across the continent for the skin, the gut, women's health and sexual complaints, and now go into skin creams. It has not been studied in people.

Also: American dwarf palm tree, cabbage palm, sabal, serenoa

A small palm whose berries are sold mostly for urinary symptoms of an enlarged prostate. Many studies, including two NIH-funded trials, lead NCCIH to conclude it is probably not helpful for that purpose.

Also: clove basil, efirin (Lagos), ntion (Efik), aramoho (Benin)

A tall basil eaten as a salad herb and long used for fevers across West Africa. In two small trials, a mouth rinse made with it reduced dental plaque, though less than the standard rinse chlorhexidine in one of them.

Also: schizandra, Wu-wei-tzŭ, wuweizi, omija

A red berry from traditional Chinese medicine, named for its five flavors and valued as a tonic. A few small trials in people exist, and it can change how the body handles some medicines.

Also: Irish moss, carrageen, carragheen, Chondrus crispus

A red seaweed of North Atlantic shores that sets into a jelly when boiled, sold today as a dried seaweed and a ready-made gel. No study has tested it in people. It carries iodine and can carry heavy metals, and a 2026 test of 66 US products found bacteria in both forms and arsenic and mercury in the dried seaweed.

Also: Alexandrian senna, Tinnevelly senna, Indian senna, sennosides

A stimulant laxative made from the leaves and pods of an African and Indian shrub, sold over the counter in teas and tablets. It works for short-term constipation, and it is meant for a week or less: long-term use brings its own problems.

Also: benne, til (Hindi), tila (Sanskrit), ellu (Tamil)

An ancient oilseed eaten as seeds, tahini and oil across Asia, Africa, the Middle East and the Americas. Controlled trials suggest modest effects on blood pressure and blood sugar. Sesame is also one of the nine major food allergens in the United States.

Also: satávari, satawar, Asparagus racemosus, Satamuli

The root of an Indian asparagus, long used in Ayurveda for women's health and to support breast milk. Evidence for milk supply is very uncertain overall, with one recent small trial reporting a benefit.

Also: shea nut butter, karité, Butyrospermum parkii, emi-ori (Yoruba)

The fat pressed from the nut of the West African shea tree, used on skin and hair and in cooking. One randomized study found a shea-based diaper emollient about as protective as petroleum jelly; allergy to it is rare but reported.

Also: sheep's sorrel, field sorrel, red sorrel, sour weed

A small, sour-leaved weed of pastures and worn fields. It is best known today as one of the four herbs in the Essiac tea mixture; it has not been studied on its own in people.

Also: shepherd's sprout, Capsella, Thlaspi bursa-pastoris, Bursa pastoris

A common weed with heart-shaped seed pods, long used in Europe for heavy bleeding. The EU accepts it for heavy periods on the strength of tradition; two small trials in Iran point the same way, but the evidence is thin.

Also: Lentinus edodes, Lentinula edodes, lentinan

A popular cooking mushroom from Japan and China, also sold in extracts for immunity. One small trial in healthy adults found changes in immune markers from eating it; the best-documented effect in people is an itchy, whip-like rash from eating it raw or undercooked.

Also: Szechuan pepper, Sichuan peppercorn, prickly ash, huajiao (Chinese)

The dried husks of a spiny Chinese shrub's small red fruits. It is known for the buzzing, numbing tingle it leaves on the lips and tongue. There are no trials of it as a medicine, but it is a documented food allergen.

Also: scullcap, madweed, hoodwort, helmet flower

A North American mint-family plant sold for anxiety, stress and sleep, often mixed with valerian. Two small trials report some benefit for mood and sleep, and it has been linked to rare liver injury, often in products that turned out to contain other herbs.

Also: red elm, moose elm, Indian elm, sweet elm

The inner bark of a North American elm, which turns slippery and gel-like in water. It is sold in lozenges for sore throats and as a powder for an upset stomach; it is considered safe, but it has not been tested on its own in people.

Also: bouncing bet, bouncing bess, fuller's herb, sweet betty

A pink-flowered roadside plant whose root and leaves foam like soap-suds in water, used in old herbal medicine for skin complaints and today in natural cleansers. It has not been studied on its own in people.

Also: yu zhu, angular Solomon's seal, fragrant Solomon's seal, Polygonatum odoratum

The knotted white rhizome of a woodland lily with arching stems and hanging bell flowers, used in European herbalism for bruises and sprains and in Chinese medicine as a nourishing food-herb. One placebo-controlled trial in older adults found changes in immune cells and gut bacteria, but no health outcome was shown.

Also: graviola, guanabana, sour sop

A tropical fruit tree whose fruit, juice and leaf tea are common across the Caribbean, and whose leaf is sold online as graviola, often with cancer claims. There are no clinical trials showing it helps people with cancer, and regular use has been linked to a rare brain disease in Guadeloupe.

Also: garden mint, spear mint, Mentha viridis

The everyday garden mint of teas, gum and toothpaste. Small studies have looked at spearmint tea for unwanted hair growth in women with high androgen levels, and at special extracts for knee pain and memory; all are early findings.

Also: fever-bush, wild allspice, spicewood, Benjamin bush

A shrub of eastern North American woods whose twigs, bark and red berries smell of allspice. It was a household fever tea and a wartime spice in the American South. It has not been studied in people.

Also: blue-green algae, Arthrospira, cyanobacteria

A dried blue-green alga (really a cyanobacterium) sold as a protein- and nutrient-rich powder. It may lower blood pressure a little; the main risk is contamination of poorly grown products with liver toxins or heavy metals.

Also: hypericum, Klamath weed, goatweed, Tipton's weed

A yellow-flowered plant sold mostly for low mood. Many studies suggest it may help mild or moderate depression over up to 12 weeks, but it weakens many important medicines, sometimes dangerously.

Also: Chinese star anise, Chinese anise, badian, badiane

The eight-pointed dried fruit that flavors Chinese five-spice, pho and mulled drinks. As a cooking spice it is recognized as safe, but the FDA has advised against drinking teas brewed from star anise after infants had seizures, and Chinese star anise can be mixed with the poisonous Japanese star anise.

Also: Stevia rebaudiana, steviol glycosides, stevioside, rebaudioside A

A South American plant whose leaves are intensely sweet, now a common zero-calorie sweetener. Purified extracts are accepted by FDA as safe in food, while the whole leaf and crude extracts are not permitted as sweeteners. WHO advises against using non-sugar sweeteners, stevia included, for weight control.

Also: queen's delight, queen's root, yaw root, Stillingia sylvatica

The root of queen's delight, a southern spurge with an acrid milky sap. It was a leading 19th-century American "alterative" for syphilis, skin disease and coughs, and it was known to cause vomiting and purging in large doses. It has not been studied in people, or even in the lab.

Also: nettle, nettles, Urtica dioica, Urtica urens

The common weed with stinging hairs, eaten as a spring green and drunk as a tea. The root is sold for an enlarged prostate, where trials suggest a modest easing of urinary symptoms; the leaf is sold for joints, hay fever and blood sugar, where the evidence is thinner.

Also: stoneroot, richweed, horse balm, knob root

A lemon-scented woodland mint of eastern North America with a rock-hard root. It was a household remedy and an Eclectic physicians' medicine in the 1800s; it has not been studied in people.

Also: Brazilian ginseng, suma root, Pfaffia paniculata, Hebanthe eriantha

A Brazilian root sold as "Brazilian ginseng" for energy, stress and sexual function. It is a root of the amaranth family (Amaranthaceae). Almost all research is in the lab; the one trial in people, in sickle cell disease, was judged too weak to show anything.

Also: sumach, Sumák (Arabic)

The dried, crushed red berries of a Middle Eastern shrub, a sour spice sprinkled on kebabs, salads and za'atar. Small trials have tested it for blood sugar and cholesterol with mixed results. It is not poison sumac, a different plant.

Also: savory, savoury, bean herb, Bohnenkraut

A peppery garden herb of the mint family, the classic seasoning for beans in European cooking. One small trial found a gel made from its essential oil helped a denture-related mouth infection; nothing else has been tested in people.

Also: cancer bush, kankerbos, kankerbossie, insiswa

A southern African shrub sold as a tonic and promoted for HIV, cancer and wasting. In a trial in adults with HIV it did not change viral load or CD4 counts, and two people taking the TB medicine isoniazid developed tuberculosis. There is no good evidence for cancer.

Also: sweet broomweed, licorice weed, vassourinha (Brazil), escobilla (Spanish)

A small, bushy weed of the tropics with a faintly sweet taste, long used as a bush tea in the Caribbean and across South America. It has been studied in the lab and in animals, not in people.

Also: violet, violets, sweet violet, Viola odorata

The garden and wild violet of old European and Persian herbals, made into syrups for coughs, sleep and "cooling". Two small Iranian trials of violet syrup reported better sleep in menopausal women and faster easing of some COVID-19 symptoms.

Also: annual wormwood, sweet Annie, huang hua hao (Chinese), qinghao

A fragrant annual herb of China, now also grown in East and Central Africa. It is the source of artemisinin, the base of today's standard malaria medicines. Its home-made tea is promoted for malaria, but in a trial the parasites often came back, and the WHO advises against using the plant for malaria in any form.

Also: za'atar, zaatar, Syrian marjoram, Bible hyssop

The wild oregano of Lebanon, Syria, Israel and Palestine, the herb in za'atar, and the plant many scholars now identify as the hyssop of the Bible. It has not been studied on its own in people.

Also: tambran (Trinidad)

A large tree with sour-sweet brown pods, eaten as fruit and made into drinks and candy. Only a few small studies in people exist. Imported tamarind candies have been linked to lead poisoning in children.

Also: common tansy, golden buttons, cow bitter, bitter buttons

A European roadside plant with flat golden button flowers and a strong camphor smell, long used for worms and to bring on periods. It contains thujone, a nerve poison, and its oil has killed people. It has not been studied in people.

Also: Russian tarragon, Artemisia dracunculus

An anise-flavored kitchen herb, also sold as "Russian tarragon" capsules for blood sugar. One small trial in people with prediabetes found modest changes; a review of such botanicals found too little evidence to recommend any. Like basil, it contains estragole.

Also: tea tree, Australian tea tree oil, tea tree essential oil, melaleuca oil

An essential oil distilled from an Australian tree's leaves, used on the skin for acne, athlete's foot, and nail fungus. A small amount of evidence suggests it might help acne and athlete's foot. It must never be swallowed.

Also: lei gong teng, tripterygium

A Chinese medicinal vine sold for rheumatoid arthritis and kidney problems. Many low-to-moderate quality studies suggest it might help some symptoms, but it can cause serious side effects, and rare deaths have been reported.

Also: Thymi herba, thyme oil, Thymi aetheroleum, Thymum

A kitchen herb that is also one of Europe's traditional cough medicines. Europe's medicines agency accepts thyme for chesty coughs with a cold on the strength of long use, not trials; syrups that pair thyme with ivy or primrose have done better than placebo in trials.

Also: Eurycoma longifolia, Long Jack, Ali's walking stick, Malaysian ginseng

The root of a slow-growing Southeast Asian tree, sold mostly as a testosterone supplement for men. Small trials suggest a modest rise in total testosterone; LiverTox records rare reports of liver injury, and surveys have found mercury in some products.

Also: puncture vine, devil's thorn, goathead, gokhru

A spiny, low-growing weed whose fruit and root are used in Ayurveda and Chinese medicine and sold today for sexual function and athletic training. Trials suggest it may help erectile function a little; they have not found that it raises testosterone or strength.

Also: Chinese rhubarb, rhubarb root, Ta-huang, Russian rhubarb

The dried root of Chinese rhubarb, a stimulant laxative. European regulators accept it for short-term use in occasional constipation in people over 12, for no more than a week.

Also: Yun Zhi, kawaratake, roof tile fungus, Coriolus versicolor

A thin, fan-shaped bracket fungus striped brown and tan like a turkey's tail. An extract of it, PSK, has been given alongside chemotherapy in Japan since the 1970s, and it has been studied in thousands of patients.

Also: haldi (Hindi), haridra (Sanskrit)

A ginger-family rhizome used as a spice and sold as turmeric or curcumin supplements. NCCIH does not yet know enough to conclude it is beneficial for any purpose, and better-absorbed formulations have been linked to liver damage.

Also: Usnea barbata, usnic acid, moss, lichen

A lichen found worldwide, used in folk medicine on wounds and for sore throats. Its main compound, usnic acid, was sold in weight-loss supplements and has caused severe liver injury, including liver failure.

Also: utazi (Igbo), arokeke (Yoruba), bush buck, Marsdenia latifolia

A bitter-sweet climbing vine whose leaves season soups and salads in southern Nigeria and are taken across West Africa for blood sugar, blood pressure and the stomach. In one small study a utazi drink on its own did not change blood sugar after a glucose test.

Also: bearberry, bearberry leaf, upland cranberry, uvae ursi folium

A low evergreen shrub whose leathery leaves are sold for bladder infections. The EU accepts it for a few days' relief of mild, recurring bladder symptoms in women, based on long use; no clinical trial of the leaf on its own exists, and it is not meant for longer use.

Also: black pepper of West Africa, Ashantee pepper, Benin pepper, African cubebs

A West African climbing pepper whose berries and leaves season soups. No study has tested it in people; the evidence that exists is market testing, which found lead above the permitted limit in samples sold in Nigeria.

Also: all-heal

A root used since ancient Greece and Rome, now sold mostly for sleep. The evidence is inconsistent, and the American Academy of Sleep Medicine recommends against it for chronic insomnia.

Also: vanilla bean, tlilxochitl (Mexican name)

The fermented, dried seed pod of a Mexican climbing orchid, the flavor of ice cream, cakes and chocolate. There is almost no research on eating vanilla for health; the few studies in people test its smell, for premature babies and for children at the dentist, and none is conclusive.

Also: vasa, adulsa, arusha, bakas

A bushy Indian shrub whose leaves are one of Ayurveda's chief cough herbs. The cough medicine bromhexine was made from one of its alkaloids, but the leaf itself has barely been studied in people.

Also: Jamaican vervain, vervine (Trinidad), blue porter weed, rooter comb

A roadside weed with long spikes of small blue-violet flowers, brewed in Trinidad and Jamaica as a "cooling" bush tea. It has lab and animal studies only; no trial in people has been done.

Also: vidanga, Viḍanga, báberang, baberang

The small, dried, pepper-like fruits of a climbing shrub of India, used in Ayurveda above all against intestinal worms. Almost all research is in the laboratory or in animals; its one study in people is a small, uncontrolled 1971 test as a contraceptive.

Also: water cress, Nasturtium officinale, Rorippa nasturtium-aquaticum, berro

A water green eaten in salads and soups and used in Iranian folk medicine for coughs and asthma. Trials of freeze-dried watercress and a watercress extract changed blood and urine markers in people; none has shown a health outcome.

Also: wheat grass, wheatgrass juice, wheat grass juice

The young grass of the wheat plant, juiced fresh or dried to a green powder. A handful of small trials in people (ulcerative colitis, thalassemia, chemotherapy) reported encouraging results, but a 2015 review called them all small with methodological problems. Its taste and nausea are the common complaints.

Also: white mulberry, common mulberry, Egyptian mulberry, Russian mulberry

The leaf of the silkworm's mulberry tree, drunk as tea in parts of Asia and sold as a supplement for blood sugar and weight. Several studies suggest it may lower high blood sugar, but many were preliminary and others found no effect.

Also: oak bark, Quercus cortex, white oak

The tannin-rich bark of oak trees, used as an astringent wash and drink. Europe accepts oak bark for traditional use in mild diarrhea and minor mouth, skin and hemorrhoid irritation, but no clinical study in people has been done.

Also: eastern white pine, white pine, Weymouth pine, Pinus strobus

The inner bark of the tall eastern North American pine. It was the lead ingredient of a popular 19th-century American cough syrup; it has not been studied in people.

Also: willow bark, white willow, European willow, Salix

A tree bark that contains salicin, which the body turns into salicylic acid, a relative of aspirin. Several trials found a willow bark extract eased low-back pain better than placebo; for joint pain the results are weaker, and it carries aspirin-like cautions.

Also: bee balm, horsemint, Monarda, elk medicine

A lavender-flowered prairie mint with a strong oregano-like scent, used as medicine and tea by the peoples of the Great Plains. It has not been studied in people.

Also: black cherry, Cerasus serotina, capuli cherry, Prunus virginiana (old name)

The bark of the North American black cherry, made into cough syrups in 19th-century American medicine. The plant contains cyanogenic compounds that can release hydrogen cyanide, and the bark has not been studied in people.

Also: lion's ear, wilde dagga, red dagga, wild hemp

A tall South African shrub with whorls of orange, tube-shaped flowers, long used for snakebite, coughs, skin complaints and seizures, and smoked for a mild high. It has not been studied in people.

Also: society garlic, wilde knoffel (Afrikaans), wilde knoflook, itswele lomlambo (isiXhosa)

A South African bulb with purple flowers and a strong garlic smell, long used there for chest complaints and worms. It has not been studied in people.

Also: Indian ginger, Canada snakeroot, colic root, heart snakeroot

A low woodland plant of eastern North America with a ginger-scented root, unrelated to kitchen ginger. The Chippewa used the root to season food. FDA lists it among plants known or suspected to contain aristolochic acid, which damages the kidneys.

Also: lettuce opium, lactucarium, poison lettuce, strong-scented lettuce

A bitter relative of garden lettuce whose dried milky sap, lactucarium, was sold in the 1800s as "lettuce opium" for sleep and pain. It now turns up among natural psychoactive products, but no clinical trials exist, and eating the plant has put people in the hospital.

Also: Dioscorea villosa, colic root, rheumatism root, true wild yam

A North American vine whose root, called colic root, was a favorite Eclectic remedy, and which is sold today, mostly as a skin cream, for menopause. In a placebo-controlled trial the cream did no better than placebo and did not change hormone levels.

Also: Hamamelis, winterbloom, snapping hazelnut, spotted alder

A shrub of eastern North American woods that flowers in late autumn. Its astringent bark and leaves, and the distilled witch hazel water on drugstore shelves, are used on the skin. Studies in people are few and small.

Also: betony, common betony, wood betony, Betonica

A woodland plant with spiked heads of reddish-purple flowers, praised at length in Culpeper's herbal. Modern research in people is limited to a few Eastern European lactation studies from the 1970s.

Also: absinthium, absinth, Absinthii herba, common wormwood

An intensely bitter, silver-gray herb, a flavoring of the liquor absinthe, used in Europe for poor appetite and indigestion. Two small trials in Crohn's disease reported benefit; its essential oil, rich in thujone, is a convulsant poison.

Also: milfoil, thousand leaf, nose-bleed, Millefolii herba

A common wayside plant with feathery leaves and flat white flower heads, long used on wounds and as a bitter for the stomach. There are no trials of it by mouth in Europe's assessment; one recent small trial in diabetes and one of an ointment after childbirth reported benefits.

Also: curled dock, sour dock, narrow dock, dock

A common weed with wavy-edged leaves and a long yellow root, used in 19th-century American medicine as a tonic and for skin conditions. No trials in people exist; the plant contains oxalic acid, and a 1990 case report describes a man who died after eating it.

Also: hierba mansa, Anemopsis

A peppery, aromatic root of wet ground in California, the Southwest and northern Mexico, long used by the Native peoples of the region. It has not been studied in people.

Also: maté, mate, Paraguay tea, yerba maté

A South American holly whose leaves make maté, a caffeinated everyday drink, also sold for energy and weight loss. Trials suggest a possible small effect on blood sugar and none on cholesterol. Maté is traditionally drunk very hot, which WHO's cancer agency links to esophageal cancer.

Also: mountain balm, consumptive's weed, bear's weed, holy herb

A sticky-leaved shrub of California and northern Mexico whose Spanish name means "holy herb"; its old name Consumptive's weed points to use for chest complaints. The research in people is two small studies, on weight and on graying hair, with little to show.

Also: johimbi, yohimbine, endun (French Congo)

The bark of a central and west African tree, sold as a supplement for erectile dysfunction, exercise and weight loss. There is not enough research to say it helps with any of them, and its main compound, yohimbine, has been linked to heart problems and seizures.

Also: Mojave yucca, Yucca schidigera, soapweed, Spanish bayonet

North American plants whose roots foam like soap. The Plains peoples washed their hair with soapweed root; Mojave yucca extract is sold today as a supplement and used as a foaming agent in foods. It has not been studied on its own in people.