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Tea Tree Oil
Melaleuca Alternifolia Leaf Oil
Australian essential oil with antibacterial activity against acne. Often misused at concentrations that irritate the skin.
What it does
Tea tree oil contains terpinen-4-ol, which has documented antibacterial activity against Cutibacterium acnes. A 1990 trial showed 5% tea tree oil comparable to 5% benzoyl peroxide for mild-to-moderate acne, with slower onset but less initial dryness. Most consumer products use lower concentrations than the trial — and most users apply it neat, which is too concentrated and causes contact dermatitis.
The evidence, graded
expert consensusTopical tea tree oil (Melaleuca alternifolia) is contraindicated during pregnancy, breastfeeding, and in prepubertal children. The 2023 systematic review of randomized trials and the ISO 4730:2017 standard both cite an absence of pregnancy-safety data; clinical case-evidence also links repeated topical exposure to estrogenic and antiandrogenic activity.Kairey 2023 · Frontiers in Pharmacology ↗ expert consensusTea tree oil is a documented cause of allergic contact dermatitis, and oxidation increases its sensitizing potency.de 2016 · Contact dermatitis ↗ Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
melaleuca alternifolia oil
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