Tea tree oil is obtained by steam distillation of the leaves of Melaleuca alternifolia. Tea tree oil is purported to have antiseptic properties, and has been used traditionally to prevent and treat infections. While numerous in vitro studies have demonstrated antimicrobial properties of tea tree oil (likely attributable to the constituent terpinen-4-ol), only a small number of randomized, controlled human trials have been published. Human studies have focused on the use of topical tea tree oil for fungal infections (including onychomycosis and tinea pedis), acne, and vaginal infections. However, no definitive evidence exists for the use of tea tree oil in any of these conditions, and further study is warranted.
Tea tree oil should be avoided orally, as reports of toxicity after oral ingestion have been published. When used topically, tea tree oil is reported to be mildly irritating, and has been associated with the development of allergic contact dermatitis, which may limit its potential as a topical agent for some patients.
Australian tea tree oil, Bogaskin® (veterinary formulation), breathaway, Burnaid® (40mg/g of tea tree oil and 1mg/g of triclosan), cymene, M. alternifolia, malaleuca, Melaleuca Alternifolia Hydrogel® (burn dressing), melaleucae, melaleuca oil, oil of mela-leuca, oleum, Oleum melaleucae, T36-C7, tea tree oil, Tebodont®, teebaum, terpinen, terpinen-4-ol, terpinenol-4, ti tree, TTO.
Note: Should not be confused with cajeput oil, niauouli oil, kanuka oil, or manuka oil obtained from other Melaleuca species.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Although available in many products, little information is available from human studies to evaluate the benefit of tea tree oil used on the skin for the treatment of acne. Tea tree oil may reduce the number of inflamed and non-inflamed lesions.
Allergic skin reactions
One small study shows that topical tea tree oil may reduce histamine-induced skin inflammation. Further research is needed to confirm these results.
Athlete's foot (tinea pedis)
Preliminary studies report tea tree oil to have activity against several fungal species. However, at this time there is not sufficient information to make recommendations for or against the use of tea tree oil on the skin for this condition.
Preliminary research reports that the use of 5% tea tree oil shampoo on mild-to-moderate dandruff may be effective and well tolerated. Further research is needed to confirm these results.
Fungal nail infection (onychomycosis)
Although tea tree oil is thought to have activity against several fungus species, there is not sufficient information to make recommendations for or against the use of tea tree oil on the skin for onychomycosis.
Tea tree oil has activity against some viruses in laboratory studies, and it has been suggested that a tea tree gel may be useful as a treatment on the skin for genital herpes. However, there is currently not sufficient information to make a recommendation for or against this use of tea tree oil.
Methicillin-resistant Staphylococcus aureus (MRSA) chronic infection (colonization)
Laboratory studies report that tea tree oil has activity against methicillin-resistant
Study results on the effects of tea tree oil mouthwash on gum inflammation and plaque are mixed. Further research is needed before a conclusion can be drawn.
Thrush (Candida albicans of the mouth)
In laboratory studies, tea tree oil can kill fungus and yeast such as
Vaginal infections (yeast and bacteria)
In laboratory studies, tea tree oil can kill yeast and certain bacteria