Neem Benefits and Therapeutic Effects

The Neem tree (Azadirachta indica) is an evergreen tree that is part of the mahogany family. The leaves, bark, flowers, and seeds are used to make remedy. Neem leaves have been used traditionally for leprosy, skin ulcers, eye disorders, stomach upset, diabetes,  diseases of the heart and blood vessels, fever, gingivitis, and liver disorders.

Neem Benefits for Health

Neem has been commonly used in traditional Indian ayurvedic, and homoeopathic medicine and has become a cynosure of modern medicine. More than 140 compounds have been isolated from different parts of neem. The therapeutic properties have been described particularly for neem leaf. Neem leaf and its constituents have been showed to exhibit immunomodulatory, antioxidant, nantimutagenic, anticarcinogenic, antiviral, antibacterial, antifungal, antimalarial, anti-inflammatory, antiulcer, and antihyperglycaemic effects.


Neem oil relieves dry skin and soothes itchy, red, irritated skin. Neem oil contains high levels of antioxidants, which help protect the skin from free radicals caused by over-exposure to sun, environmental toxins and other damaging factors. A study published in May 2001 (American Journal of Clinical Nutrition) scientists found that fatty acids, which are found in neem, provided some protection against ultraviolet light, the cause of photoging. Because neem contains antibacterial effects, it is highly helpful in treating epidermal conditions such as acne, eczema and psoriasis. Experiments have shown that people with psoriasis who have taken neem leaf orally, combined with tropical therapy with neem extracts and neem seed oil, achieve results at least as favorable as those who use coal tar and cortisone. A study in 1979 demonstrated neem extract to be beneficial in treating ringworm, scabies, eczema, and some forms of dermatitis.


neemNeem seed and leaf have anti-microbial, anti-fungal and anti-viral effects. In test tubes, neem has been shown to have important properties on both gram-positive and gram-negative organisms and other bacteria that cause a wide array of human and animal diseases including Escherichia coli, streptococcus and salmonella. A 0.2% concentration of neem had the same anti-bacterial property as penicillin G. Its antiseptic effects help to prevent periodontal diseases. In a scientific review published in the June 2002 edition of the “Current Science“, the authors concluded that neem oil has a wide spectrum of antibacterial action in vitro against fourteen different strains of pathogenic bacteria. In a clinical trial, a cream containing neem seed extract, saponins of Sapindus mukerossi and quinine hydrochloride eliminated all symptoms in 10 of 14 women with chlamydia compared with none of 4 women given placebo cream.

Gum Disease

Neem oil is used in lotions, soaps, shampoos, and toothpastes. It helps treat fungal infections, lice, dry scalp, skin disorders, and gingivitis. Neem oil is frequently added to natural toothpastes as a purifier and as an antimicrobial agent that helps prevent dental diseases. Mouthwashes containing neem can significantly inhibit the growth of the bacteria Streptococcus mutans in the mouth, according to a study reported in the  2001 of the Indian Journal of Dental Research. Applying neem leaf extract gel to the teeth and gums twice  daily for six weeks might reduce plaque formation, according to developing research. In 2004, a study published in the Journal of Ethnopharmacology; 36 men were assigned to 6 weeks of therapy with either a gel containing neem extract, or a mouthwash containing chlorhexidine gluconate. Study findings demonstrated that the neem-based gel was more effective in reducing plaque buildup than the mouthwash.

Mosquito Repellent

Some researches demonstrates that neem oil may help protect against insect bites. Neem’s mosquito repellent effects are an important weapon in the fight against malaria in third world countries. In 1994 the the Malaria Research Centre of Delhi, investigated whether kerosene lamps with 1% neem oil can protect people from mosquito bites. Neem oil openly reduced the number of bites on the volunteers and the number of mosquitoes caught. In a study reported in the “Southeast Asian Journal of Tropical Medicine and Public Health” in 1995, researchers discovered that a blend of neem oil and coconut oil may act as a mosquito repellent. Different concentrations of neem oil mixed in coconut oil were applied to the exposed body parts of volunteers. Results showed 81%-91% protection during 12 hour period of observation from the bites of anopheline mosquitoes. In another study, repellent action of neem oil was studied against different mosquito species. 2% neem oil mixed in coconut oil provided 96-100% protection from anophelines, 85% from Aedes, 37.5% from Armigeres whereas it demonstrated wide range of efficacy from 61-94% against Culex spp. A July 2008 study reported in the Malaria Journal shows the 50% reduction in the mosquito population after applying neem seed powder to mosquito breeding areas.

Head Lice

Head louse infestations are prevalent worldwide. Neem effectively kills lice in all stages of their life cycle. An anti-louse shampoo (Licener®) based on a neem was studied in vitro and in vivo on its efficacy to eliminate head louse infestation by a single therapy. In a 2011 study reported in “Parasitology Research“, the hair of 12 children being selected from a larger group due to their intense infestation with head lice were incubated for 10 minute with the neem-based shampoo. It was found that after this short exposition period, none of the lice had survived, when being observed for 22 hour. Other living head lice were in vitro incubated within the undiluted product. It was seen that a total submersion for just 3 minute prior to washing 3× for 2 minute with tap water was sufficient to kill all motile stages.

The eggs (nits) of head and body lice were incubated for 5, 10, 15, 20, 30 or 45 min into a neem seed extract contained in a fine shampoo formulation (Wash Away® Louse provided by Alpha-Biocare GmbH, Düsseldorf). It was found that an incubation time of just 5 minute was enough to prohibit any hatching of larvae, whilst 93 ± 4% of the larvae in the untreated controls of body lice hatched respectively approximately 76% of the controls in the case of head lice. In a study 60 heavily lice-infested female and male children were selected and subjected to the therapy with a neem seed based shampoo. Twenty to thirty ml of the neem seed extract shampoo were thoroughly mixed with completely wet hair and rubbed in to reach the skin of the scalp. After 10, 15 and 30 minute, the neem shampoo was washed out. The neem seed shampoo proved to be extremely powerful against all stages of head lice. At the pediatric clinic of Iserlohn a study was conducted on a product under the name of “Neem-Extrakt FT-Shampoo”. In this clinical study, children were treated both for head lice and scab mites. With head lice, the therapy was especially successful when the hair was shampooed on the 1st, 3rd and 10th day.

Birth Control

Vaginal suppositories and creams made with neem oil are becoming the birth control method of popular in India. Several studies demonstrated that neem oil appears to be a safe and  effective contraceptive, pre and post coital. When tested against human sperm neem extract at 1000 mg was able to kill all sperm in only 5 minutes and required only 30 minutes at a 250 mg level. Neem oil appears to be the most powerful form of neem for birth control, especially hexane extracted neem oil. After a single injection of a minute amount of neem oil in the uterine horns, a potent cell-mediated immune response reaction produced a long term and reversible block in fertility (up to 12 months).

This herb may become the first  effective birth control “pill” for men. In both India and the United States, studies show neem extract reduces fertility in male monkeys without it hurting libido or sperm production. Neither neem leaf extract in water nor neem leaf oil alters the rate spermatogenesis. But, neem seed oil and neem bark extract caused arrest of spermatogenesis within two months, with a decrease in the number of Leydig cells. Male antifertility activity of neem leaf extract was examined in rats. The infertility effect was seen in treated male rats as there was a 66 % decreased in fertility after 6 weeks, 80% after 9 weeks, and 100% after 11 weeks. Neem leaf tablets ingested for one month produced reversible male antifertility without affecting sperm production or libido. In a test of neem’s birth control properties with members of the Indian Army, daily oral doses of several drops of neem seed oil in gelatin capsules were given to 20 married soldiers. The effect took 6 weeks to become 100% effective, it remained effective during the entire year of the study and was just reversed 6 weeks after a man no longer took the capsules.


Traditional Indian ayurvedic medicine has recommended the use of neem leaf, seed, and bark, for reducing arthritic pain and inflammation and for halting the progression of the disease. Clinical trials have showed that the anti-inflammatory effects of various compounds in neem leaves are equally as effective as phenyl butazone and cortisone. Neem leaf and bark extracts have been shown to be a more strong inhibitor of prostaglandin synthetase than acetylsalicylic acid and pethidine hydrochloride. A study at the Department of Pharmacology at Rajshahi Medical College, scientists found that neem extract has a important effect on inflammation.The anti-inflammatory effects of azadirachtin, the active ingredient in neem oil have been established. A study reported in the February 2010 edition of the Journal of Biological Chemistry demonstrated hat azadirachtin support an anti-inflammatory response in human skin cell lines by blocking the expression of certain enzymes involved in producing inflammation, such as COX-2 (cyclooxygenase 2).


Neem is known to have powerful gastroprotective and antiulcer properties. Standardized aqueous extract of neem leaves has been reported to show both ulcer protective and ulcer healing effects in normal as well as in diabetic rats. The effect of neem extract on gastric ulceration was examined in albino rats. Neem extract (100-800 mg/kg po, 100-25 mg/kg ip) significantly inhibited gastric ulceration induced by indomethacin (40 mg/kg). In a 2004 clinical trial at the “Indian Institute of Clinical Biology” demonstrates neem bark causes important decreases in gastric acid secretion (77%), as well as gastric secretion volume (63%) and pepsin activity (50%). The bark extract when taken at the dose of 30–60 mg twice daily for 10 weeks nearly completely healed the duodenal ulcers monitored by barium meal X-ray or by endoscopy. One case of esophageal ulcer and one case of gastric ulcer healed completely when treated at the dose of 30 mg twice daily for six weeks.


Neem seed and leaf extracts have antiviral effects. Neem acts as an antiretroviral agent via inhibition of viral invasion of host cells. Neem has been shown to be efficacious against herpes virus and the viral DNA polymers of the hepatitis B virus. Research at “Johns Hopkins University” demonstrated that neem “provided significant protection” against the Herpes simplex virus type 2 (HSV-2) in mice infected with the extremely infectious virus. A study in the Aug 2010 edition of the Phytotherapy Research showed that neem bark extract inhibit the entry of herpes simplex virus (HSV) type 1 into the target cells in the lab and may help prevent or treat herpes infections. The antiviral and virucidal effect of an extract of neem leaves was investigated to determine its activity against the Coxsackie B group of viruses. Neem leaves extract inhibited the replication of 6 types of Coxsackie virus B. Observations of virus inactivation and population reduction in the experiment showed that neem was most powerful against Coxsackie virus B-4 early in its replicative cycle. A 2002 research findings that neem leaf extract inhibits the growth of Dengue virus, type 2, a viral hemorrhagic fever related to Ebola. In vitro tests demonstrated it completely inhibited the virus. In vivo tests conducted on mice demonstrated the neem leaf extract resulted in inhibition of the virus as confirmed by the absence of symptoms.  Ten HIV-positive participants were included in a study. Bodyweight, blood cell count, and CD4+ cell count were measured before and after the trial period. All received capsules containing neem extract (1000 mg), once daily for 30 days. The increases in body weight and blood cell count after 30 days was important among all subjects. The scientists also found that neem extract protected 75% of human cells in a test tube from the HIV virus.


Several components found in neem leaves may be helpful in cancer therapy including the  vitamin C, beta carotene  quercetin, azadirachtin, azadirone, deoxonimbolide, kaemferol, nimbolide and glucopyranoside. An ethanolic extract of neem leaf reduced the incidence of chemical-induced gastric tumors in mice; and neem-treated monocytes induced apoptosis in cervical and prostate cancer cells. In India, Japan  and Europe researchers have found that polysaccharides and liminoids in neem bark, leaves and seed oil reduced tumors and cancers and were effective against lymphocytic leukemia. Neem leaf extract demonstrated an adjuvant immune response to tumor growth in mice as well as protection from leucopenia caused by chemotherapy. Neem extract may help kill prostate cancer cells, according to a research reported in the Journal of Ethnopharmacology in April 2006. A 2011 research reported in “Cancer Biology and Therapy” showed that neem may offer anti-cancer effects, including immune-stimulating and tumor-suppressing activities. A new research, performed with mice and  rats, showed that the inclusion of a preparation from neem leaf added to an antigen helped create higher quantities of an immune antibody beneficial for shielding against breast cancer.

Side Effects

Don’t take any neem products internally if you are trying to conceive a child. Taking neem oil internally is not recommended, for children. Oral administration of neem oil resulted in serious poisoning in children. These severe adverse effects include  blood disorders, seizures, loss of consciousness, coma, brain disorders, and death. Neem oil has been found to produce Reye’s syndrome symptoms in infants who are exposed to neem oils.

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