- Neem has a long history of use in India. The leaf and bark extracts were recommended by herbal practitioners for gastrointestinal upsets, skin ulcers, infections and malaria. Neem twigs were used regularly as toothbrushes, and the leaf gel was used to fight periodontal disease (inflammatory disease of the gum).
- The extracts from neem often have a pungent smell similar to garlic. This is because they contain sulfurous compounds. Neem has been reported to reduce plaque formation, act as a mosquito repellent, treat psoriasis vulgaris (chronic skin disease with reddened lesions covered by silvery scales) and aid in the healing of gastroduodenal ulcers. However, there is currently insufficient evidence to recommend for or against these uses. In the United States, neem is used mainly for its antibacterial, antifungal, insect repellant, contraceptive, and hypothetical "life extension" qualities.