Tranexamic Acid

Highly effective melasma treatment with a differentiated mechanism: plasmin/PGE2 pathway inhibition upstream of MITF rather than direct tyrosinase suppression. This makes it mechanistically complementary to all tyrosinase inhibitors — and particularly synergistic with niacinamide (which acts at melanosome transfer). 2025 clinical evidence is compelling: RCT (n=50) confirmed oral and topical TXA achieve equivalent MASI reduction (~58.86% vs 50.88%), both superior to baseline; niosomal TXA 2% + niacinamide 4% achieved 66.7% mMASI reduction, outperforming 4% HQ with far fewer adverse reactions. Japan quasi-drug since 2002 (topical) and OTC oral since 2007. Not EU-restricted. Excellent safety profile at cosmetic concentrations. Preferred over hydroquinone by current clinical data. Niosomal delivery is a formulation upgrade worth implementing: same or better efficacy at half the concentration with improved stability.

No FDA restriction for topical cosmetic use at typical 2–5% brightening concentrations. Oral TXA is an FDA-approved prescription drug (Lysteda) for heavy menstrual bleeding — systemic risk profile of oral/IV does NOT apply to topical cosmetic use. Claim strategy critical: structural brightening claims are acceptable; physiological depigmentation claims risk FDA drug classification.