Tea tree oil or melaleuca oil is a clear to very pale golden hydrophobic essential oil with a fresh camphoraceous odor. It is taken from the leaves of the Melaleuca alternifolia which is native to the northeast coast of New South Wales, Australia. The oil has beneficial medical properties (including antiseptic and antifungal, antibacterial action), and is also believed to have beneficial cosmetic properties. Tea tree oil is usually used diluted, as reactions are common with pure tea tree oil, and it can cause irritation in dilution as well.
Tea tree oil should not be confused tea tree oil soap with tea oil, the sweet seasoning and cooking oil from pressed seeds of the tea plant (drinking tea) Camellia sinensis or the tea oil plant Camellia oleifera.
Tea tree oil has strong activity against Staphylococcus aureus including tea tree essential oil MRSA. When used at 5% concentration it has not been shown to cause drug resistance; however, some resistance occurs at lower concentrations of usage such as 0.5% strength.
Tea tree oil is a known antifungal agent, effective in vitro against multiple dermatophytes found on the skin. In vivo, shampoo with 5% tea tree oil has been shown to be an organic tea tree oil effective treatment for dandruff due to its ability to treat Malassezia furfur, the most common cause of the condition.
Effectiveness of topical tea tree oil preparations for Candidiasis is supported by its ability to kill Candida in vitro. In the treatment of moderate acne, topical tea tree oil acne application of 5% tea tree oil has shown an effect comparable to 5% benzoyl peroxide, albeit with slower onset of action. There is some very limited research that has shown that tea tree oil may have topical desert essence tea tree oil anti-viral activity, especially with the Herpes virus (cold sores, chicken pox and shingles blisters, etc.)