NEEM LEAF & OIL (Azadirachta indica)

Latin: Azadirachta indica
Sanskrit: Nimba

WHAT IT DOES: Neem leaf is very strong,  bitter in taste and cold in action.  Internally it reduces fever and inflammation, reduces itching, and kills microbes and fungus.  Neem oil is used externally to heal wounds and boils.


SAFETY ISSUES: Do not use internally for longer than three weeks unless under professinal guidance due to dampening effect on digestive, sexual and reproductive functions. External use is safe in all cases.

Plain neem leaf as sold over the internet in capsule form should not be used. It needs to be properly prepared first and mixed with other items into a a formula.

• Dried powder: one to two grams two times per day
• 1:5 tincture: 10-20 drops two times per day
• Concentrated powder extract: 150-250 mg two to three times per day

The neem tree is a native Indian evergreen that grows up to 70 ft high.  It is so esteemed that a foundation was formed dedicated solely to neem.  Ayurvedic doctors use neem leaves for skin diseases, itching, and fever, especially malarial fever.  They also use it internally and externally for all forms of fungal and other infections.  We use concentrated neem leaves at our clinic to treat skin diseases with severe itching (neem oil), and intestinal problems related to candidiasis or other fungal infections.  We often combine neem in formulas with other anti-fungal plants, and tell patients to restrict sugar intake and take acidophilus capsules.  This helps kill the “bad guy” intestinal bacteria, restricts their favorite fuel (sugar), and adds “good guy” acidophilus back into the intestine.  A few weeks on this sort of anti-fungal program can work wonders with these types of infections, even is persistant cases.

Neem oil is used in India in numerous varieties of hair lotion, medicated soap and toothpaste.  It is considered to be effective as a topical treatment for chronic skin conditions, ulcers and leprosy.  The warm oil is also useful when applied to treat ear infections (Chadha et al., 1985).  Traditionally used to treat malaria, neem is a very bitter and potent plant, so it should be used only when other methods have failed.

Research Highlights

• Oral administration of dry neem leaf for 24 days resulted in a reduction in the weight of the seminal vesicles and prostate of albino rats, showing an anti-androgen effect (Kasutri et al., 1997).  However, it is important to note that the dosage—20-60 mg per day—was much higher than the recommended human dose.  A review of the toxicity data by the Pharmacognosy department at the University of Utrecht in the Netherlands concluded, “reported toxicity of preparations and isolated compounds are low, except for the seed oil” (Van der Nat et al., 1991).

• Test tube studies of neem seed extract on the human malaria parasite showed strong inhibitory effect by way of a different mechanism of action than other anti-malaria drugs.  Neem seed is active not only against the parasite stages that cause the initial clinical infection but also against the stages responsible for malaria transmission (Dhar et al., 1998).

• When applied to the skin, solutions of 1-4% neem oil in 96-99% coconut oil afforded 81-91% protection against mosquito bites for 12 hours (Mishra et al., 1995, Sharma et al., 1993).

• When applied with urea to rice crops, lipid neem extracts slowed mosquito breeding, reduced incidence of Japanese encephalitis, and significantly increased grain yield in a cost-effective manner (Rao et al., 1995).

• In a study of 814 people with scabies, topical application of a skin paste made of neem leaves (4 parts) and turmeric root (1 part) cured 97% of the cases within three to 15 days of treatment (Charles & Charles, 1992).

• The insecticide activity of neem extracts seems to come from its ability to reduce appetite and disrupt growth in certain insects, including mosquitoes (Ley, 1990).

• Application of neem oil appears to induce a strong blockage of fertility.  In a controlled study of fertile female Wistar rats, a single intrauterine injection dose of neem oil caused a 100% infertility rate for periods of 100 to 180 days, while all the control animals became pregnant.  Within five months, more than 50% of the test females regained fertility.  There was no visible effect on ovarian function (Upadhyay et al., 1990).

• In a related study, the researchers discovered that neem oil acts as an alternative to vasectomy.  As with females, a single-dose injection of neem oil in male rats caused infertility for 8 months, blocking sperm production without affecting testosterone (there did appear to be a reduction in testicular size).  The effects may be due to a local immune response against the sperm (Upadhyay et al., 1993).

• In an unrelated study, oral administration of neem extract for 10 weeks caused a significant decrease in total testosterone in male rats.  There were no cytotoxic effects (Parshad et al., 1994).

• The anti-fertility effect of neem oil was also reported in rhesus monkeys (Bardhan et al., 1991).

• Oral administration of neem seed extract (Praneem) caused abortion early on in the pregnant female baboons and bonnet monkeys.  The treatment was tolerated well, and tests of blood chemistry and liver function were normal.  The primates regained fertility subsequent to treatment (Mukherjee et al., 1996).

• As a result of the aforementioned effects, researchers investigated neem oil for hormonal properties.  They found that it had no estrogenic, anti-estrogenic or progesterone-related activity.  They concluded that since the post-coital contraceptive effect of neem oil seems to be non-hormonal, it is less likely to elicit side effects than the steroidal contraceptives (Prakesh et al., 1988).