Overview
Neem is used for tooth plaque, gum disease (gingivitis), lice, to repel insects, and for other conditions, but there is no good scientific evidence to support most of these uses.
How does it work ?
Uses & Effectiveness ?
Possibly Effective for
- Tooth plaque. Most research shows that applying a gel containing neem leaf extract to the teeth or using a neem mouthwash can reduce the amount of plaque on the teeth. But it might not be as helpful as using chlorhexidine mouthwash.
- A mild form of gum disease (gingivitis). Most research shows that applying a gel containing neem leaf extract or using a neem mouthwash can reduce gingivitis in some people, but it doesn't seem to be as helpful as chlorhexidine mouthwash and it may not be effective for people with long-standing gingivitis.
- Lice. Clinical research shows that applying a neem extract shampoo to the scalp once completely cures head lice in children.
Insufficient Evidence for
- Insect repellent. Early research shows that applying extract of neem root or leaf to the skin helps repel black flies.
- Mosquito repellent. Early research shows that applying neem oil cream to the skin seems to protect against some types of mosquitos.
- Stomach ulcers. Early research suggests that taking neem bark extract by mouth for 10 weeks might help heal ulcers in the stomach and intestines.
- Scaly, itchy skin (psoriasis). Early research suggests that taking neem extract by mouth for 12 weeks, along with daily sun exposure and the application of a coal tar and salicylic acid cream, might make the symptoms of psoriasis less severe.
- Abortion.
- An eating disorder (anorexia nervosa).
- Asthma.
- Birth control.
- Diabetes.
- Eye disorders.
- Fever.
- Heart disease.
- Hemorrhoids.
- Indigestion (dyspepsia).
- Infection of the intestines by parasites.
- Insect bite.
- Leprosy.
- Liver disease.
- Malaria.
- Nosebleeds.
- Pain.
- Scleroderma.
- Wound healing.
- Other conditions.
Side Effects
When applied to the skin: Neem leaf extract gel is POSSIBLY SAFE when applied inside the mouth for up to 6 weeks. Neem oil or cream is POSSIBLY SAFE when applied to the skin for up to 2 weeks.
Special Precautions and Warnings
Breast-feeding: There isn't enough reliable information to know if neem is safe to use when breast-feeding. Stay on the safe side and avoid use.
Children: Neem extract shampoo is POSSIBLY SAFE in children when applied once or twice to the head for 10 minutes, then rinsed with warm water. Neem seeds and seed oil are LIKELY UNSAFE when taken by mouth in children. Serious side effects in infants and small children can happen within hours after taking neem oil. These serious side effects include vomiting, diarrhea, drowsiness, blood disorders, seizures, loss of consciousness, coma, brain disorders, and death.
"Auto-immune diseases" such as multiple sclerosis (MS), lupus (systemic lupus erythematosus, SLE), rheumatoid arthritis (RA), or other conditions: Neem might cause the immune system to become more active. This could increase the symptoms of auto-immune diseases. If you have one of these conditions, it's best to avoid using neem.
Diabetes: There is some evidence that neem can lower blood sugar levels and might cause blood sugar to go too low. If you have diabetes and use neem, monitor your blood sugar carefully. It might be necessary to change the dose of your diabetes medication.
Reduced ability to have children (infertility): There is some evidence that neem can harm sperm. It might also reduce fertility in other ways. If you are trying to have children, avoid using neem.
Organ transplant: There is a concern that neem might decrease the effectiveness of medications that are used to prevent organ rejection. Do not use neem if you have had an organ transplant.
Surgery: Neem might lower blood sugar levels. There is a concern that it might interfere with blood sugar control during and after surgery. Stop using neem at least 2 weeks before a scheduled surgery.
Interactions ?
Medications for diabetes (Antidiabetes drugs) interacts with NEEM
Neem might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking neem along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.Medications that decrease the immune system (Immunosuppressants) interacts with NEEM
Neem might increase the immune system. By increasing the immune system, neem might decrease the effectiveness of medications that decrease the immune system.
Some medications that decrease the immune system include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and others.Lithium interacts with NEEM
Neem might have an effect like a water pill or "diuretic." Taking neem might decrease how well the body gets rid of lithium. This could increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium. Your lithium dose might need to be changed.
Moderate Interaction
Be cautious with this combination
Dosing
ADULTS
APPLIED TO THE SKIN:
- For a mild form of gum disease (gingivitis): A neem leaf extract gel has been applied to the teeth and gums twice daily for 6 weeks. 15 mL of 2% neem solution used as a mouthwash for 30 seconds after brushing daily for 3 weeks.
- For tooth plaque: A neem leaf extract gel has been applied to the teeth and gums twice daily for 6 weeks. 15 mL of 2% neem solution used as a mouthwash for 30 seconds after brushing daily for 3 weeks. 5 mL of neem solution used as a mouthwash twice daily for 30 days.
APPLIED TO THE SKIN:
- For lice: 100 mL of a specific neem extract shampoo (Licener, Pronovo Laboratories) applied to dry hair for 10 minutes then rinsed with warm water once or repeated for a second application.
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Balappanavar, A. Y., Nagesh, L., Ankola, A. V., Tangade, P. S., Kakodkar, P., and Varun, S. Antimicrobial efficacy of various disinfecting solutions in reducing the contamination of the toothbrush -- a comparative study. Oral Health Prev.Dent. 2009;7(2):137-145. View abstract.
Bandyopadhyay, U., Biswas, K., Sengupta, A., Moitra, P., Dutta, P., Sarkar, D., Debnath, P., Ganguly, C. K., and Banerjee, R. K. Clinical studies on the effect of Neem (Azadirachta indica) bark extract on gastric secretion and gastroduodenal ulcer. Life Sci. 10-29-2004;75(24):2867-2878. View abstract.
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Jones, I. W., Denholm, A. A., Ley, S. V., Lovell, H., Wood, A., and Sinden, R. E. Sexual development of malaria parasites is inhibited in vitro by the neem extract azadirachtin, and its semi-synthetic analogues. FEMS Microbiol.Lett. 7-15-1994;120(3):267-273. View abstract.
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Talwar, G. P., Shah, S., Mukherjee, S., and Chabra, R. Induced termination of pregnancy by purified extracts of Azadirachta Indica (Neem): mechanisms involved. Am J Reprod.Immunol. 1997;37(6):485-491. View abstract.
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Vanka, A., Tandon, S., Rao, S. R., Udupa, N., and Ramkumar, P. The effect of indigenous Neem Azadirachta indica [correction of (Adirachta indica)] mouth wash on Streptococcus mutans and lactobacilli growth. Indian J.Dent.Res. 2001;12(3):133-144. View abstract.
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Aladakatti RH, Ahamed RN. Effect of Azadirachta indica leaves on rat spermatozoa. Indian J Exp Biol 1999;37:1251-4. View abstract.
Ali BH. Toxicology of Azadirachta indica. J Ethnopharmacol 1994;42:71-2. View abstract.
Balappanavar AY, Sardana V, Singh M. Comparison of the effectiveness of 0.5% tea, 2% neem and 0.2% chlorhexidine mouthwashes on oral health: a randomized control trial. Indian J Dent Res. 2013;24(1):26-34. View abstract.
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Bhanwra S, Singh J, Khosla P. Effect of Azadirachta indica (Neem) leaf aqueous extract on paracetamol-induced liver damage in rats. Indian J Physiol Pharmacol 2000;44:64-8. View abstract.
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