Tea tree oil, also known as melaleuca oil, is an essential oil that comes from steaming the leaves of the Australian tea tree. When used topically, tea tree oil is believed to be antibacterial. Tea tree oil is commonly used to treat acne, athlete's foot, lice, nail fungus and insect bites.
Experts consider tea tree oil to be safe as a topical treatment, and you can apply it directly to the skin on a daily basis. When applied to the skin in its pure (100% oil) form, tea tree oil seldom causes irritation. But some people develop an allergic rash (contact dermatitis).