Among the home remedies, tea tree oil is said to be effective. This essential oil is derived from the leaves of the Melaleuca alternifolia, is said to have antibacterial, antifungal and antiviral properties. Even though, there is no conclusive evidence to prove the antiviral activity of tea tree oil, it is said that use of tea tree oil for cold sores results in reducing the healing time to almost half. It is also believed to be good for preventing the outbreaks, if used at the very onset of symptoms.