Educational information, not medical advice — ask your doctor or midwife.
Tea tree oil is the essential oil steam-distilled from the leaves of Melaleuca alternifolia, a small tree from coastal New South Wales, Australia. People put it on the skin, mostly for acne, athlete's foot and dandruff.
The oil is strong stuff. It is sold watered down in gels, creams and shampoos, and also as a pure oil meant to be mixed with a carrier oil first. It is for skin only, and swallowing it can poison you.
Here is the short verdict. Small human trials back a mild benefit for acne, athlete's foot and dandruff. Most other claims rest on tradition and lab tests, and traditional use is not proof that something works or that it is safe.
Tea tree oil kills germs in the lab. Whether that fully explains what it does on skin is less certain.
The main compound is terpinen-4-ol. In test tubes it appears to damage the outer coat of bacteria and yeasts. The cell then leaks and dies.
In lab and animal tests, the oil also lowers some signals linked to swelling and redness. That may be why treated acne spots look calmer. This has not been shown directly in people.
In small human trials, a 5% gel cut the number of acne spots over several weeks. Stronger solutions helped athlete's foot. So the skin effects are real but modest, and the exact path is still partly a guess.
Almost all skin products use the oil diluted. Common ready-made forms:
- 5% gels and spot creams for acne - 5% shampoos for dandruff or an itchy scalp - foot creams, powders and sprays, often 10% or more - nail solutions, from 25% up to pure oil - soaps, wipes, and mouth rinses that are spat out
Pure (neat) oil is also sold in small dark glass bottles. Labels normally tell you to mix a few drops into a carrier oil, such as almond or coconut oil, before use.
There are also cleaning products and pet shampoos that contain it. Pet products are a known poisoning risk for cats and dogs when too strong.
Aboriginal people of the Bundjalung region in eastern Australia used crushed Melaleuca leaves on the skin and breathed in the steam. Written records of this use are thin and come mostly from later observers.
The oil itself was distilled and studied in the 1920s by the Sydney chemist Arthur Penfold. He reported strong germ-killing power in lab tests, and the oil sold well.
Australian soldiers carried it in first aid kits during the Second World War. Modern antibiotics then pushed it aside. Interest came back in the 1970s and 1980s, and farming of the tree grew with it.
Stop using it and see a doctor or pharmacist if: - the skin becomes red, swollen, blistered or weeping - a rash spreads past the treated area - acne or foot itch has not improved after about 12 weeks - a nail or foot infection spreads, smells bad, or you have diabetes or poor circulation
Get emergency help at once if anyone swallows tea tree oil. Call your poison centre or emergency number, even if the person seems well.
Warning signs after swallowing include vomiting, slurred speech, confusion, unsteady walking, extreme sleepiness and loss of consciousness. Take the bottle with you. Do not try to make the person vomit.
If oil gets in the eye, rinse with clean water for several minutes and get medical advice.
In Australia, tea tree oil products are regulated by the TGA, many as listed medicines. In the United States it is sold as a cosmetic or supplement, and the FDA has not approved it to treat any disease. In the United Kingdom and the EU it is mainly a regulated cosmetic ingredient.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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