Tea Tree Oil: half-life, strengths and approval status

What is tea tree oil?

Tea tree oil is an essential oil steam-distilled from the leaves of the Australian tea tree (Melaleuca alternifolia), used on the skin for acne, athlete's foot, nail fungus and lice. NCCIH says a small amount of evidence suggests it might help acne and athlete's foot, and that it should not be swallowed.

Also known as: Melaleuca alternifolia, melaleuca oil, tea tree essential oil.

Strengths studied

Trials used mouthwashes with 0.2% to 0.5% tea tree oil and gels with 5%; side effects were minor except at concentrations of 25% or more (Kairey 2023). These are study protocols, not a recommendation.

Approval status and how it is used

NCCIH says tea tree oil is promoted for use on the skin and should not be swallowed. In the EU, tea tree oil has a traditional-use monograph for small superficial wounds, insect bites, small boils and mild acne, itching and irritation in mild athlete's foot, and minor mouth inflammation, from age 12 (EMA). EMA bases this on long-standing ("traditional") use: there is not enough evidence from clinical trials, but the effect is plausible and the herb has been used safely this way for at least 30 years, including at least 15 years in the EU.

What studies show: NCCIH says a small amount of research suggests it might help acne and athlete's foot, though it may not work as well as standard athlete's foot treatments, and the evidence for nail fungus is not enough to draw conclusions. A 2023 review of 46 trials found mouthwashes may limit dental plaque and 5% gels may help gum disease alongside dental cleaning, but rated the research quality as poor to modest (Kairey 2023). A Cochrane review of 6 trials for eyelid mites (Demodex blepharitis) rated the evidence very low certainty (Savla 2020).

Safety: NCCIH says tea tree oil should not be swallowed; taken by mouth it can cause confusion, unsteadiness, inability to walk and coma. On the skin most people have no problems, but redness and irritation can occur, more often with old products or ones exposed to heat, light or air. EMA lists pain, itching, burning, stinging, redness, swelling and allergic reactions, and rare burn-like skin reactions.

Tea tree oil half-life and time to peak

• Half-lifeNot listed
• Time to peak (Tmax)Not listed

Tea tree oil is used on the skin and in the mouth, not swallowed, so a half-life or time to peak does not apply.

How to track tea tree oil in Dose Track

1. Add tea tree oil as a custom compound. Start typing its name and Dose Track fills in the details from its research library for you to check, and it sits next to everything else you take.
2. Log each application when you use it, so your history shows how often you used it and where.
3. Set reminders on your own schedule, whether that is daily, weekly or every few days.
4. Your log is stored on your phone and no account is needed. Data only leaves it for features you choose, like AI answers and lab reading.

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Related compounds

Frequently asked questions

Sources

1. NIH National Center for Complementary and Integrative Health. Tea tree oil (updated April 2025).
2. European Medicines Agency, HMPC. Tea tree oil (Melaleucae aetheroleum): summary for the public.
3. Kairey L, et al. Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health: a systematic review of randomized controlled trials. Front Pharmacol. 2023;14:1116077.
4. Savla K, Le JT, Pucker AD. Tea tree oil for Demodex blepharitis. Cochrane Database Syst Rev. 2020;6(6):CD013333.

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