What Is Neem?

Neem (Azadirachta indica) is a type of tree indigenous to India that is used in alternative medicine to prevent gum disease and treat head lice.

It is available as a capsule, powder, oil, tincture, cream, or mouthwash. Some remedies are made from the bark, flowers, or fruit of the neem tree.

This article discusses the purported uses of neem, its side effects, and the risks associated with taking neem supplements.

Dietary supplements are not regulated in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement that has been tested by a trusted third party, such as USP, ConsumerLabs, or NSF. However, even if supplements are third-party tested, that doesn't mean they are safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.

Supplement Facts

  • Active Ingredients(s): Isoprenoid, non-isoprenoids
  • Alternate Name(s): Indian neem, margosa tree
  • Legal Status: Not currently regulated by the FDA
  • Suggested Dose: No suggested recommended dose.
  • Safety Considerations: Not suggested during pregnancy, breastfeeding, or during childhood due to lack of research. Do not consume neem oil.

Benefits and Uses of Neem

The purported health-friendly properties of Neem are numerous and have led to it being used as an antioxidant and for antifungal, antibacterial, and pest control applications. It's also used to reduce inflammation and boost the immune system.

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent a disease.

Research on the potential health benefits of neem is limited. While neem has been studied in lab and nonhuman animal studies for potential uses (e.g., anticancer activity, lower blood sugar, stomach ulcers, malaria, and acne), there is not enough evidence to support its use for any of these reasons due to lack of human research. More research is needed with well-designed, placebo-controlled, peer-reviewed human research studies.

Dental Health

A few studies have evaluated whether neem can help fight the plaque buildup on teeth and prevent a gum disease called gingivitis. However, the results are mixed.

A 2017 randomized, double-blinded study in the Journal of Contemporary Dental Practices reported that neem mouthwash was as effective as commercial mouthwashes containing chlorhexidine gluconate, a substance commonly used to prevent gum disease. However, the study was small, involving only 40 people for one week.

A more extensive review of studies published in 2017 in the International Journal of Dental Hygiene did not reach the same conclusions. The researchers could find no evidence that neem mouthwash is a reasonable alternative to chlorhexidine mouthwash.

Lice

Neem seed extract shampoo has been found to be effective in ridding head lice.

A study done in 2007 included 60 children who used the shampoo for different time exposures. According to the results, the neem seed extract effectively eliminated the lice for all periods (5 to 30 minutes). No side effects like skin irritation were observed. More research should be done regarding the use of neem for lice.

What Are the Side Effects of Neem?

Consuming a supplement like neem may have potential side effects. These side effects may be common or severe. Due to lack of research, little is known about the safety of short-term or long-term use of neem; however, there are some possible concerns and side effects.

Topical use (placed on skin) can cause:

  • Allergic dermatitis (skin inflammation)
  • Dermatitis on the scalp (used by an individual with hair loss)

Neem oil should not be consumed orally.

Oral consumption can lead to:

  • Vomiting
  • Drowsiness
  • Diarrhea
  • Encephalopathy (diffuse disease of the brain that affects its function or structure)
  • Seizures and coma

Precautions

Children and people who are pregnant or breastfeeding should not use neem supplements due to the lack of safety research in those groups.

Consuming neem oil is not advised. One case report indicated that oral consumption may lead to neem oil poisoning, which can cause symptoms like nausea, vomiting, and seizures.

Dosage: How Much Neem Should I Take?

There is not enough scientific evidence to determine a standard or appropriate dose of neem. More research is needed on dosages for specific health needs and populations. Please talk with your healthcare provider before you start taking neem or any supplement.

What Happens If I Take Too Much Neem?

As a rule of thumb, never take more neem than the manufacturer's recommended dosage. This is true for any of its forms. If you experience side effects, stop taking neem and call your healthcare provider.

Interactions

It is essential to carefully read a supplement's ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

At this time, there is limited information regarding known interactions with different medications because of limited human research. Studies suggest that neem has blood sugar lowering effects. Therefore, taking neem with diabetes medications, such as metformin, could cause blood sugar to drop too low.

Talk to your healthcare provider before starting neem or any other supplement to determine whether it is safe to take with your current medications.

Neem powder
Verywell / Anastasia Tretiak

How to Store Neem

Store neem according to manufacturer's directions. Discard as indicated on the package.

Frequently Asked Questions

  • What dosage of neem should I take?

    At this time, there is no recommended dose. Talk with your healthcare provider about taking neem or any other herbal supplement.

  • Does neem seed extract kill lice?

    Yes, neem seed extract shampoo has been found to be effective in getting rid of head lice.

  • Can I take neem while pregnant?

    At this time, it is not recommended for pregnant people to take neem. Always talk with your healthcare provider about starting a supplement when pregnant.

Sources of Neem & What to Look For

Neem can be found online and in many dietary supplements or natural food stores. It comes in many forms, including capsules, tinctures, powders, oil, creams, shampoos, and mouthwashes.

There are no guidelines for the appropriate use of neem. Once on the market, dietary supplements like neem are not as strictly regulated by the FDA as drugs. Because of this, a supplement's purity and safety can vary from one manufacturer to the next.

Summary

Neem has been traditionally used to treat a wide range of health conditions, including head lice and dental issues like gingivitis. However, most claims are not backed by enough human data and require more research. Neem is available as a capsule, powder, oil, tincture, cream, or mouthwash.

Just like with any other supplement, consult with your healthcare provider first if you are thinking about taking neem.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Reddy IVR, Neelima P. Neem (Azadirachta indica): a review on medicinal kalpavriksha. International J of Economic Plants. 2022;9(1):59-63. doi:10.23910/2/2021.0437d 

  2. Mishra A, Dave N. Neem oil poisoning: case report of an adult with toxic encephalopathy. Indian J Crit Care Med. 2013;17(5):321–322. doi:10.4103/0972-5229.120330

  3. Jalaluddin M, Rajasekaran UB, Paul S, et al. Comparative evaluation of neem mouthwash on plaque and gingivitis: a double-blind crossover study. J Contemp Dent Pract. 2017;18(7):567-571. doi:10.5005/jp-journals-10024-2085

  4. Dhingra K, Vandana KL. Effectiveness of Azadirachta indica (neem) mouthrinse in plaque and gingivitis control: a systematic review. Int J Dent Hyg. 2017;15(1):4-15. doi:10.1111/idh.12191

  5. Abdel-Ghaffar F, Semmler M. Efficacy of need seed extract shampoo on head life of naturally infected humans in EgyptParasitol Res. 2007;100(2):329-332. doi:10.1007/s00436-006-0264-2

  6. Greenblatt DT, Banerjee P, White JM. Allergic contact dermatitis cause by neem oil. Contact Dermatitis. 2012;67(4):242-243. doi:10.1111/j.1600-0536.2012.02099.x

  7. Reutemann P, Ehrlich A. Neem oil: an herbal therapy for alopecia causes dermatitis. Dermatitis. 2008;19(3):E12-15.

  8. Iyyadurai R, Surekha V, Sathyendra S, Paul Wilson B, Gopinath KG. Azadirachtin poisoning: a case report. Clin Toxicol. 2010;48(8):857-858. doi:10.3109/15563650.2010.518148

  9. Mishra A, Dave N. Neem oil poisoning: case report of an adult with toxic encephalopathy. Indian J Crit Care Med. 2014;62(3):337-339. doi:10.4103/0972-5229.120330 

  10. Pingali U, Ali MA, Gundagani S, Nutalapati C. Evaluation of the effect of an aqueous extract of Azadirachta indica (neem) leaves and twigs on glycemic control, endothelial dysfunction and systemic inflammation in subjects with type 2 diabetes mellitus - a randomized, double-blind, placebo-controlled clinical study. Diabetes Metab Syndr Obes. 2020;13:4401-4412. doi:10.2147/DMSO.S274378

By Alena Clark, PhD
Alena Clark, PhD, is a registered dietitian and experienced nutrition and health educator

Originally written by
Cathy Wong
Cathy Wong

Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.

Learn about our editorial process