Tea tree oil treats fungal infections of the nails, athlete's foot, vaginal infections, parasites and supports dental health, according to Mayo Clinic. It also treats allergic reactions in the skin, and as of 2015, early evidence indicates that it may be effective for treating acne. Tea tree oil comes from the leaves of Melaleuca alternifolia, and although it has antiseptic properties when used topically, it can be toxic if ingested by mouth.
The chemicals in tea tree oil treat infections caused by ringworm, lice and scabies, and the oil is an effective local antiseptic for use on burns, boils, insect bites and stings, cuts and abrasions, notes WebMD. Tea tree oil is also used to treat mouth, nose and ear infections, and it can be added to warm water and inhaled to soothe inflammation in the lungs, relieve bronchial congestion and calm a cough.
As of 2015, early studies show that individuals with dandruff who use a 5 percent tea tree oil shampoo for three minutes a day for four weeks experience less itchiness, greasiness and scalp lesions, states WebMD. Rinsing the mouth with tea tree oil appears to be beneficial for treating thrush in individuals with HIV/AIDS when anti-fungal medications, such as fluconazole, are ineffective.