Neem (Azadirachta indica) is a tree native to the Indian subcontinent (1).

Various parts of this tree have long been utilized in traditional Asian medicine. Historically, it has been used to treat pain, fever, and infection, white its twigs have been used to clean teeth (2, 3).

Still, you may be curious to know whether any of these claims are merited.

This article takes a deep dive into the science behind neem extract to explain its uses, potential benefits, and any risks.

Neem plant (Azadirachta indica) growing wildShare on Pinterest
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Sometimes called “the village pharmacy,” neem is a unique medicinal plant in that all of its parts — including its leaves, flowers, seeds, fruit, roots, and bark — can be used (4, 5).

Centuries-old manuscripts reveal some of the historical applications of this tree. Its flowers were used to treat bile duct disorders, its leaves to treat ulcers, and its bark to treat brain illnesses (6).

Over 140 diverse active compounds have been isolated from various parts of the plant. These active compounds give neem its antioxidant, antimicrobial, antiparasitic, anti-inflammatory, antidiabetic, and wound-healing properties (4, 7, 8).

Although the mechanisms by which neem works aren’t entirely clear, research into this plant is ongoing (5, 6, 8).

Summary

Neem packs over 140 active compounds that may give it numerous antioxidant and anti-inflammatory effects. It has long served as a treatment for ulcers, gastrointestinal troubles, and brain ailments.

Although scientific research into neem is in its beginning stages, it shows promise for several aspects of health, including blood sugar management, as well as benefits for your hair, skin, teeth, liver, and kidneys.

Keep in mind that further human studies are necessary.

May promote hair health

Neem seed extract contains azadirachtin, an active compound that may fight parasites that affect hair and skin, such as lice. Azadirachtin works by disrupting parasite growth and interfering with reproduction and other cellular processes (9).

In a study that tested the efficacy of a neem-based shampoo on head lice in children, leaving shampoo in the hair for 10 minutes killed the lice while being gentle on the skin (10, 11).

Neem extract and nimbidin, a compound found in neem oil, may also treat dandruff due to its anti-inflammatory and antimicrobial properties. Dandruff and scalp irritation may result from fungal buildup on the scalp (8, 12).

May boost dental and oral health

Chewing neem bark to promote oral hygiene is a common practice in India (13).

Neem’s antiseptic, anti-inflammatory, antioxidant, and immune-boosting properties may promote oral health. Although more research is needed, studies indicate that neem may relieve pain and help treat gingivitis, periodontitis, and tooth decay (3).

Furthermore, test-tube studies suggest that neem may minimize bacteria’s ability to colonize the surface of your teeth, thus reducing plaque formation (14).

Plus, in a 21-day study including 45 people with gingivitis, neem mouthwash was found to be as effective as chlorhexidine mouthwash — a heavy duty prescription mouthwash — at reducing gum bleeding and plaque (15).

May aid liver and kidney health

Neem’s antioxidant and anti-inflammatory properties may help fight oxidative stress, which may in turn promote liver and kidney health.

Oxidative stress is caused by a buildup of unstable molecules called free radicals. Although your body naturally produces free radicals as a byproduct of metabolism, external sources increase their presence.

Some drugs, including cancer medication, painkillers, and antipsychotics, may contribute to oxidative stress, leading to tissue damage in your liver and kidneys (16).

Interestingly, one study on rats found that neem leaf extract reduced liver damage induced by high-dose acetaminophen (17).

Another rat study showed similar effects, suggesting that neem extract improved kidney tissue damage caused by chemotherapy medication (18).

However, studies in humans are needed.

May improve skin health

Neem seed oil is rich in fatty acids, including oleic, stearic, palmitic, and linoleic acids. Collectively, these fatty acids have been shown to have anti-inflammatory, antioxidant, and antimicrobial properties that promote healthy skin (19).

Keep in mind that while Ayurvedic medicine — an Indian traditional healing system — uses neem to treat psoriasis and eczema, very few scientific studies support these claims (20).

Acne

Historically, neem has been used to treat acne, reduce blemishes, and improve skin elasticity (21).

Indeed, studies suggest that neem oil’s antibacterial properties combat acne.

A test-tube study showed that neem oil may aid long-term acne treatment when added to solid lipid nanoparticles (SLNs), a new type of drug formulation that offers a stable release of active ingredients (21).

All the same, research in humans is necessary.

Ulcer and wound healing

Animal studies suggest that neem leaf extract accelerates wound healing through an increased inflammatory response and the formation of new blood vessels (8, 22).

In a 2013, 34-day case study, applying 100 mg of neem oil topically twice daily completely healed chronic skin ulcers (23).

In another study, 6 people with intestinal ulcers took 30 mg of neem extract orally twice daily. After 10 days, acid secretion had declined significantly, and after 10 weeks, the ulcers were almost completely healed (24).

Yet, this was a fairly small study. More human research is needed.

Other potential benefits

Neem may have several other health benefits, though results are mixed, and further studies in people are necessary.

Antimalarial effects

Neem contains active compounds called limonoids. A study in mice found that limonoids may be as effective at targeting malaria-infected cells as conventional treatments using chloroquine (2, 25).

However, some test-tube studies show no positive effect of neem extract on malaria outcomes (26).

Keep in mind that neem is not widely used to treat malaria at this time.

Antifertility treatment

Neem has also been considered as an alternative to a vasectomy due to its antifertility effects. A vasectomy is a surgical procedure that sterilizes people with testicles by stopping the release of sperm.

Animal studies note that neem may immobilize and kill sperm with no long-term consequences (2, 4, 27).

Diabetes management

Some animal studies indicate that neem leaf extract may be a candidate for new diabetes medications (4, 5, 8).

That’s because neem extract may help revive cells that produce insulin — the hormone that helps control blood sugar — and lower blood sugar levels (28).

All the same, human studies are lacking.

Summary

Although neem appears to have numerous therapeutic effects, results are inconclusive since they’re based on test-tube and animal research with very few human studies.

Although neem products are derived from natural sources, they’re not inherently safe for human use. Therefore, it’s important to take precautions when using neem products.

Neem seed extracts are comprised of various fatty acids and about 2% bitters, which are considered toxic. Levels of these bitters differ between products and may be influenced by extraction and storage methods (29).

Avoid oral intake

You should treat oral intake of any neem product with extreme caution, if not avoid it altogether.

In some cases, infants have experienced severe poisoning after being given neem oil at doses of 0.18–1.06 ounces (5–30 mL) (30, 31).

Similarly, one man experienced neurological and psychotic symptoms after consuming 2.1 ounces (60 mL) of neem oil (23).

Although one animal study showed no evidence of toxicity at levels as high as 2.27 grams of neem per pound (5 grams per kg) of body weight, these results may not translate to the same effect in humans (2, 8).

Furthermore, anecdotal evidence links excessive neem leaf tea intake to kidney failure (2).

Other applications

People taking diabetes medications should consult their doctor before using neem to avoid the risk of very low blood sugar levels (5).

While topical use appears to be safe if diluted with other ingredients, direct application to the skin isn’t advised, as it may result in irritation (32).

Neem has been shown to have long-term contraceptive effects in men after a single dose. Due to its ability to halt sperm development and the limited research into its safety, you should avoid neem if you’re trying to have children (27).

Infants, children, and pregnant or nursing people are discouraged from using neem because of its mixed safety record and lack of comprehensive research.

Summary

Though neem may be safe to use topically when diluted, taking it orally may harm your health. Currently, research is not sufficient enough to thoroughly define the risks and side effects of neem and neem-based products.

Neem is commonly sold in oil, extract, powder, and supplement forms, as well as added to hair, skin, and oral care products. You can usually find these products at health and beauty outlets.

Neem oil can be applied to the skin or mixed with shampoo or creams. It’s considered safe for oral intake when diluted with alcohol or taken in tablet or powder form.

However, regulation of neem is limited, so many products aren’t tested for safety or purity.

While its topical application is mostly regarded as safe, extraction techniques and specific uses may affect its overall toxicity (5).

Read the label and follow the directions listed, as these vary from product to product.

It’s important to note that no standard dosage exists, and information on its effectiveness is unknown. To minimize health risks, avoid self-medicating and consult a healthcare professional before using any neem product.

Summary

Neem and neem-based products are widely available in health stores. Yet, there’s no standardized dosage, especially for oral intake. To minimize risk, talk with your doctor before trying neem.

Neem is a unique plant in that all its parts — its leaves, flowers, seeds, fruit, root, and bark — exhibit medicinal properties.

Although scientific research on this supplement is still in its early stages, evidence suggests that it may treat dandruff, lice, gingivitis, and dental plaque, as well as promote wound healing.

However, dosage information is currently unknown, and a lack of regulation means that many neem products aren’t tested for safety and purity. Thus, it’s best to talk with a healthcare professional before trying any neem product.