Neem Tree has been highly successful against harmful fungi, parasites, and viruses. Although it can destroy these, it does not kill off beneficial intestinal flora nor produce adverse side effects. Neem is toxic to several fungi that attack humans, including the causes of athletes foot and ringworm and candida, which cause yeast infections and thrush. In fact, Neem extracts are some of the most powerful Antifungal plant extracts found in the Indian pharmacopia that are used for these conditions. The compounds gedunin and nimbidol , found in the tree leaves, control the fungi listed above. Basing their studies on the ancient tradition of using Neem to purify the air surrounding sick people, two Indian researchers found that Neem smoke was successful in suppressing fungal growth and germination.

One of Neem's stronger advantages is its effect upon the skin in general. It has been most helpful in treating a variety of skin problems and diseases including psoriasis, eczema and other persistent conditions.

According to a report from the National Research Council's Ad Hoc Panel of the Board on Science and Technology for International Development, Neem preparations from the leaves or oils can be used as general antiseptics. Because Neem contains antibacterial properties, it is highly effective in treating epidermal conditions such as acne, psoriasis and eczema. It is also used for treating septic sores, infected burns, scrofula, indolent ulcers and ringworm. Stubborn warts can be cleared up when a high-quality Neem product is used. Unlike synthetic chemicals that often produce side effects such as rashes, allergic reactions, or redness, Neem does not seem to create any of these results.

Early Ayurvedic practitioners believed high sugar levels in the body caused skin disease. Neems bitter quality was considered to counteract the sweetness. Indians historically bathed in Neem leaves steeped in hot water. This is still considered a common procedure for curing skin ailments or allergic reactions.

Psoriasis has been successfully treated with Neem oil. The oil moisturizes and protects the skin while healing the lesions, scaling and irritations. Experiments have shown that patients with psoriasis who have taken Neem leaf orally, combined with topical treatment with Neem extracts and Neem seed oil, achieve results at least as positive as those who use coal tar and cortisone, the more traditional treatments. Coal tar products are messy and smelly and cortisone can thin the skin when used repeatedly. Neem has neither side effect. It can be used for extended periods of time without any side effects, is easy to apply and is relatively inexpensive.