Cited skincare — every flag names its source, no upsell.
Te

Tea Tree Oil

Melaleuca Alternifolia Leaf Oil

A plant oil with real evidence against acne bacteria. In one trial it did about as well as benzoyl peroxide, slower but less drying.

What it does

Its main compound fights acne bacteria. A 1990 trial found 5% tea tree oil about as good as 5% benzoyl peroxide for mild to moderate acne, slower to work but less drying at first. Most products use less than the trial did.

The EU’s ingredient database lists it as an antioxidant (slows reactions with oxygen, like going rancid).European Commission, CosIng (© European Union, CC BY 4.0) · uses put in plain words by Drop ↗

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. Fresh oil is a weak to moderate sensitizer, and oxidation makes it more allergenic. Most reported reactions came from putting the pure oil on skin; cosmetics were the cause in a minority.de Groot 2016 · Contact dermatitis ↗
expert consensusSCCP/1155/08 (December 2008) found tea tree oil a skin sensitizer and, based on clinical data, its current use levels shown to induce contact allergy. Oxidation products formed with air and heat are considered to contribute. Neat oil and some formulations at 5% or more can irritate skin and eyes. Without adequate skin-absorption data, its safety could not be assessed. In 2004 the committee had found undiluted oil as a commercial product not safe, on sparse data.SCCP 2008 · European Commission SCCP (adopted 16 December 2008) ↗

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

Pairs worth knowing

Niacinamide (Vitamin B3) · works together ↗Ceramides · works together ↗Retinol · worth separating ↗Tretinoin · worth separating ↗Benzoyl Peroxide · worth separating ↗

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How Drop works · 5 minNatural Ingredients Can Still Irritate Skin — and Often Do'Natural' tells you almost nothing about how skin tolerates an ingredient. Here is which natural ingredients are common irritants and why labels mislead.

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