Tea tree oil, derived from the leaves of Melaleuca alternifolia, is commonly used as a topical treatment for acne. Its use is supported by both traditional use and scientific studies, with the greater weight from recent clinical research. The oil possesses antimicrobial and anti-inflammatory properties, largely attributed to its major active component, terpinen-4-ol. These properties are relevant to acne, which often involves Cutibacterium acnes (formerly Propionibacterium acnes) proliferation and skin inflammation.

Several randomized controlled trials have investigated tea tree oil’s efficacy in managing mild to moderate acne. A notable study published in the Medical Journal of Australia (1990) found that a 5% tea tree oil gel was similarly effective as 5% benzoyl peroxide in reducing the number of inflamed and non-inflamed lesions, though tea tree oil worked more slowly but caused fewer side effects such as dryness and irritation. A 2007 double-blind randomized trial further supported its efficacy, reporting significant improvements in both total lesion count and acne severity index compared to placebo.

While the overall body of evidence is not as extensive as for some conventional treatments, and sample sizes have typically been small, current research suggests tea tree oil is a scientifically validated, albeit moderately effective, option for topical acne management. Caution is advised due to the risk of skin irritation or allergic reactions.