Tea Tree

Tea tree usually refers to Melaleuca alternifolia leaf oil, although some cosmetics also use tea-tree extracts or waters. The essential oil contains terpinen-4-ol and other volatile compounds studied for antimicrobial and anti-inflammatory activity.

Clinical studies of standardized tea-tree-oil gels suggest modest benefit for acne, but the evidence base is much smaller than for established acne treatments such as topical retinoids or benzoyl peroxide. In ordinary cosmetics, tea tree is best treated as a supportive blemish-care ingredient whose tolerability depends strongly on concentration and formulation.