Tea tree oil is an essential oil that comes from steaming the leaves of the Australian tea tree. It is also known as melaleuca oil and has antibacterial properties when used topically. Tea tree oil is commonly used to treat acne, athletes foot, lice, nail fungus, and insect bites. It is available as an oil and in many over-the-counter skin products, including soaps and lotions. However, tea tree oil should not be taken orally as it can cause serious symptoms if swallowed. Some research suggests that tea tree oil might be helpful for acne, athlete’s foot, and nail fungus. Tea tree oil can cause skin irritation, allergic skin rash, itching, stinging, burning, scaling, redness, and dryness in some people. It should not be used by people with eczema. Tea tree oil is distilled from the leaves of the Melaleuca alternifolia plant, found in Australia, and possesses antibacterial, anti-inflammatory, antiviral, and antifungal properties.