Herb library · Herb · Azadirachta indica (syn. Melia azadirachta)

Neem

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.

Serious warning

Neem (margosa) oil swallowed by mouth has caused severe poisoning with seizures, metabolic acidosis, liver failure and deaths, particularly in young children, according to LiverTox (NIH) and published case reports.

Traditional use

Native to India and grown throughout the country, neem (Nimba in Sanskrit) appears in the oldest Ayurvedic texts. Dutt's 1877 compilation from Sanskrit medical works records that Hindu physicians used the bark, leaves and fruit, gave the leaf juice with honey for jaundice and skin complaints, and that the bitter leaves were also cooked as a pot-herb in soups and curries; the physician Chakradatta prescribed a poultice of neem leaves and sesame seeds. The leaves were used on the skin and the bark as a bitter tonic; the seed oil was rubbed into the skin and made into soap, and it is also used as an insecticide. Today neem is sold in toothpaste, mouthrinse, soaps and skin products.

Traditional energetics

Ayurveda
Taste (rasa): bitter and astringent. The Materia Medica of the Hindus (1877), p. 136 (opens in a new tab)
Galenic (hot or cold, dry or moist)
Cold and dry. Pharmacographia Indica (1890), vol. 1, p. 324 (opens in a new tab)

What studies show

Limited
Plaque and gum inflammation: a 2017 systematic review found 3 small randomized trials in which neem mouthrinse did about as well as chlorhexidine alongside tooth brushing, but the trials were poorly reported with unclear risk of bias, and the authors say high-quality trials are needed.
Insufficient
Other uses taken by mouth: we found no systematic review of human trials, so there is not enough evidence to judge them.

Be careful of

AmountDo not give neem oil by mouth to anyone, and never to a baby or child. Case reports describe vomiting, drowsiness, seizures, severe metabolic acidosis, brain swelling and liver failure within hours, and some deaths.
ConditionLiverTox (NIH) rates neem oil a probable rare cause of liver injury. The oil's content varies between batches, and some outbreaks may have come from look-alike seeds mixed into the oil.
PregnancyNCCIH advises talking with your clinician before using Ayurvedic products while pregnant or nursing.
NoteSome Ayurvedic preparations include metals. The FDA warns that this makes some Ayurvedic products potentially harmful, and a 2015 survey found high lead or mercury levels in some of the supplements tested.
Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, 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.

“The bitter leaves are used as a pot-herb being made into soup or curry with other vegetables.”

Udoy Chand Dutt, The Materia Medica of the Hindus (1877), p. 136. See the page · Read the full passage

“This tree, in Sanskrit Nimba and Arishta, is a native of India, and is cultivated in all parts of the country on account of its medicinal properties.”

William Dymock, C. J. H. Warden and David Hooper, Pharmacographia Indica (1890), vol. 1, p. 323. See the page · Read the full passage

“It has been used in the manufacture of soap.”