Tea tree oil is believed to have antibacterial, anti-fungal and anti-viral properties that assist with stimulating the immune system. "It's a reliable antiseptic," says Asa Hershoff, author of Homeopathic Remedies: A Quick and Easy Guide to Common Disorders and Their Homeopathic Treatments. "There just aren't that many substances that have all the therapeutic applications that tea tree oil does." In addition, although tea tree oil is slower to show benefits than benzoyl peroxide, Hershoff says it actually results in less itching, scaling and irritation.