Herb library · Herb · Vernonia amygdalina (syn. Gymnanthemum amygdalinum)
Bitter leaf
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.
Traditional use
Cooked as a leafy vegetable, especially in Nigeria, and widely used across Africa for malaria, stomach complaints and fever. In a 2025 Nigerian survey, almost everyone had heard of it, and about four in five linked it to keeping blood sugar in check; many also believed it helps with weight loss. In 1915 J. H. Holland recorded it as ewuro at Abeokuta, used there as a chewstick, as a toothstick at Katagum in the north, and in Sierra Leone as a bitter and a soup leaf, soaked before cooking.
What studies show
- Insufficient
Malaria: in the one clinical trial, a fresh-leaf infusion gave an adequate clinical response at day 14 in 67% of people, but only 32% of those cleared the parasites completely, and in 71% of them the infection came back. Reviews note this recurrence problem in clinical studies.
- Insufficient
Blood sugar and weight: glucose-lowering and weight effects have been reported in laboratory and animal studies; we found no controlled trials in people.
Be careful of
Cautions
- ConditionMalaria can be deadly if not diagnosed and given prescription medicine quickly (CDC). Do not rely on bitter leaf for it; see a clinician for fever after being where malaria spreads.
- InteractionIn laboratory tests a bitter leaf extract inhibited several liver enzymes that process common medicines, so it could change drug levels. Researchers advise monitoring people who take it alongside medicines, and it is widely used by people with diabetes.
- NoteExcessive consumption can be harmful, and leaves grown beside heavy-traffic roads can carry higher levels of heavy metals from the soil.
- Ask a clinicianTalk with a clinician or pharmacist before using it in medicinal amounts if you take prescription medicines (especially for diabetes), are pregnant or breastfeeding, or are giving it to a child.
From the old books
What herbals and dispensaries of the past printed. History, in their words.
“Used as a chewstick (Abeokuta, Irving, Herb. Kew), as a toothstick, Katagum (Dalziel, Herb. Kew), as a bitter Sierra Leone (Kirk, Fl. Trop. Afr. l.c.), and described as possessing a medicinal bitter root, St. Thomas (Hiern, Cat. Welw. Afr. Pl. iii. p. 530).”
“The leaves are soaked in water and used for soup, also used in palaver sauce, Sierra Leone (Scott Elliot, Col. Rep. Misc. No. 3, 1893, p. 42).”
Sources
- A clinical trial of the traditional medicine Vernonia amygdalina in the treatment of uncomplicated malaria (J Altern Complement Med, 2009) (opens in a new tab) · NIH · read September 25, 2026
- A review of efficacy and safety of Ugandan anti-malarial plants with application of RITAM score (Malar J, 2023) (opens in a new tab) · NIH · read September 25, 2026
- Cytochrome P450 Enzyme Inhibition and Herb-Drug Interaction Potential of Medicinal Plant Extracts Used for Management of Diabetes in Nigeria (Eur J Drug Metab Pharmacokinet, 2021) (opens in a new tab) · NIH · read September 25, 2026
- Awareness, knowledge and belief regarding bitter leaf use: A cross-sectional study in Nigeria (PLoS One, 2025) (opens in a new tab) · NIH · read September 25, 2026
- About Malaria (opens in a new tab) · CDC · read September 25, 2026
Reviewed September 25, 2026.