Tea tree oil has been recognized as a potent antiseptic
anecdotally for much longer than there has been scientific evidence. However, recent studies support a role for tea tree oil in skin care and treatment of various ailments.
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 effective treatment for dandruff
due to its ability to treat Malassezia furfur
, the most common cause of the condition.
Also effective in treating the most common forms of athletes foot fungal infections.[citation needed
It is also effective in treating the eye ailment blepharitis.[citation needed
Tea Tree Oil is used medically as well as in cosmetic products.
Effectiveness of topical tea tree oil preparations for Candidiasis
is supported by their ability to kill Candida in vitro.
In the treatment of moderate acne
, topical application of 5% tea tree oil has shown an effect comparable to 5% benzoyl peroxide
, albeit with slower onset of action.
In another study in 2007 5% strength gel was compared against a placebo, with statistically significant results.
Tea tree oil is also effective for treating insect bites,
boils and minor wounds.
It has also been known to help soothe sunburn,
and bee stings.
Diluted solutions of tea tree oil are sold as remedies which claim to treat bacterial and fungal infection in pet fish.
Toothpastes and mouthwashes containing tea tree oil are shown to be effective for a number of oral problems. Some of these include halitosis
(bad breath), gum disease, and canker
There is some limited research that has shown that tea tree oil may have topical anti-viral activity, especially with the Herpes
virus (cold sores, chicken pox
blisters, warts, etc.)
I guess i kind of answered my own question by looking on wikipedia. They also have some side effects listed:
Tea Tree oil is used almost exclusively externally.
Data on oral use of tea tree oil in humans in large quantities is sparse aside from several anecdotal reports of side effects following oral ingestion.
Symptoms may include ataxia
A small number of people experience allergic contact dermatitis as a reaction to dermal contact with tea tree oil. In an Italian study of 725 consecutive patients, patients were patch tested with undiluted, 1% and 0.1% Tea Tree Oil. For undiluted tea tree oil, nearly 6% of the patients observed positive reactions of skin irritation. Only 1 of 725 patients observed a positive reaction of skin irritation with the 1% dilution. None of the 725 patients observed adverse reactions with the 0.1% dilution.
Allergic reactions may be due to the various oxidation products that are formed by exposure of the oil to light and/or air.
External application of undiluted tea tree oil and/or at inappropriate high doses has been associated with toxicity, including death, in cats and other animals.
A disputed case study reported in The New England Journal of Medicine concluded that "repeated topical exposure to lavender and tea tree oils probably caused prepubertal gynecomastia
" (abnormal breast development) in three young boys.
The study involved just three individuals and found lavender to be the only common ingredient used by the boys in the study. While all three cases involved the use of products containing lavender oil
as an ingredient, only one boy also used products containing tea tree oil. In all cases, the prepubertal gynecomastia reversed after several months. Use of the products containing lavender and tea tree oils were also discontinued during this time. In the same paper, results from cell culture assays indicated that both essential oils exhibit weak estrogenic and antiandrogenic properties in vitro
, but no tests were conducted in vivo. Researchers also indicated that other components in these products may also have contributed to the gynecomastia, or that genetics might play a role. Researchers also noted that estrogenic or antiandrogenic activities have also been reported for some other commonly used essential oils as well as some foods such as almonds and peanuts, but cited no associated cases of prepubertal gynecomastia.
Others, primarily in the cosmetics industry, have cast doubt on the conclusions of the article and dismissed the study as having used "poor methodology".
If used in concentrations below 4% or particularly below 1%, tea tree oil may fail to kill bacteria and create an evolutionary pressure which may result in them becoming less sensitive to tea tree oil and even some antibiotics in vitro
Tea tree oil may cause hearing loss when used in the ears.