Tea Tree Oil
Tea tree oil comes from
the leaves of an Australian tree called Melaleuca alternifolia.
It is an essential oil with a long history of use as a natural
remedy for skin ailments and other conditions. Unfortunately,
sometimes “natural” is confused with “non-toxic” or “non-poisonous”.
Tea tree oil, like many
other “natural” substances, can indeed be poisonous if used in the
wrong way, especially if swallowed. In 2008, U.S. poison centers
received more than twice as many calls about tea tree oil than any
other named essential oil, including cinnamon oil, clove oil, and
eucalyptus oil. More than 15 percent of people exposed to tea tree
oil were treated in a hospital or doctor’s office.
Tea tree oil is sold as a
pure essential oil, in over-the-counter and herbal remedies for skin
conditions, and as an ingredient in household cleaning products.
The National Library of Medicine (NLM) lists a number of traditional
or theoretical uses of tea tree oil. NLM notes that these uses
have not all been tested for safety or effectiveness. Skin
conditions feature prominently in traditional uses of tea tree oil:
bruises, burns, canker sores, corns, eczema, insect bites,
psoriasis, rosacea, scabies, skin infections, etc. A number of
respiratory conditions are noted: colds, cough, bronchial
congestion, and nose and throat irritation. A wide variety of other
conditions are also listed as traditional uses: melanoma, body odor,
and infections of the bone and prostate.
Medical studies: A
number of studies have examined the effects of tea tree oil on
individual cells; many of these indicate some activity against
microbes and fungi. There are few studies in humans that affirm the
effectiveness and safety of tea tree oil and that have been
successfully repeated. So far, studies do not support the idea that
tea tree oil boosts the immune system.
A few studies of effects
on skin conditions include:
A 1994 study compared
tea tree oil to the antifungal drug clotrimazole in treating
fingernail fungus. Both had approximately the same effect.
A 1990 study comparing
tea tree oil to benzoyl peroxide in treating acne found that
both were effective, tea tree oil took longer to work, and the
tea tree oil patients had fewer side effects.
A 1992 study of tea
tree oil, the antifungal drug tolnaftate, and a placebo showed
that tea tree oil was no better than the placebo in curing the
fungus infection, though it did
improve the patient’s symptoms as much as tolnaftate.
Side effects: Tea
tree oil can sometimes irritate the skin, especially in higher
concentrations. It has also caused allergic skin reactions. There is
a single report of breast enlargement in a young boy who used
products containing lavender oil and tea tree oil; laboratory
studies of the oil itself indicated that tea tree oil may have
hormonal effects. (It’s likely that if this were a common effect it
would have been noted long ago; the authors published the
information so that physicians could consider essential oils when
treating boys with breast enlargement.)
Poisoning: Tea tree
oil is known to be poisonous if swallowed. A child who swallowed a
small amount given to him by mistake went into a coma (from which he
recovered). Tea tree oil should NOT be taken by mouth for any
reason, even though some traditional uses include tea tree oil as a
mouthwash, treatment for bad breath, and treatment of toothache and
Tea tree oil and pets:
Veterinary toxicologists have reported that large amounts of tea
tree oil applied to the skin of cats and dogs caused poisoning.
Symptoms have included muscle tremors, weakness, difficulty in
walking, low body temperature, and excessive salivation. With pets,
as with people, following label instructions is essential.
Tea tree oil is found in some household products, including cleaning
products. It is promoted as being “natural” and “better for the
environment”. As noted above, “natural” does not necessarily mean
“non-toxic” or “non-poisonous”; tea tree oil is irritating to some
people and is poisonous to swallow. Also, studies would be needed to
determine if tea tree oil is environmentally safe. These products
should be used according to label instructions and stored safely in
their original containers, out of reach of children, and apart from
medicines and food.
The bottom line:
Tea tree oil has been used as a “natural” remedy for a long time,
especially for skin afflictions. There is some scientific evidence
that tea tree oil can be effective for certain skin conditions. It
is poisonous if swallowed and so should not be used in or around the
mouth at all.
If someone may have
swallowed tea tree oil, call the Poison Center right away at
1-800-222-1222. Don’t wait to see what will happen first, as
swallowed tea tree oil can cause dangerous poisoning in less than
Pannowitz DL, Barnetson RS. A comparative study of tea tree oil vs.
benzoyl peroxide in the treatment of acne.
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Buck DS, Nidorf
DM, Addino JG. Comparison of two topical preparations for the
treatment of onychomycosis: Melaleuca alternifolia (tea tree)
oil and clotrimazole.
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Henley DV, Lipson
N, Korach KS, Bloch CA. Prepubertal gynecomastia linked to lavender
and tea tree oils. N Engl J Med 2007;356:479-85.
Morris, M. C.,
Donoghue, A., Markowitz, J. A., and Osterhoudt, K. C. Ingestion of
tea tree oil (Melaleuca oil) by a 4-year-old boy. Pediatric
Emergency Care 2003;19:169-171.
Tong MM, Altman
PM, Barnetson RS. Tea tree oil in the treatment of tinea pedis.
Australia J Dermatol
Villar D, Knight
MJ, Hansen SR, Buck WB. Toxicity of melaleuca oil and related
essential oils applied topically on dogs and cats. Vet Human Toxicol