A fermentation-derived brightener with decent trial support and a known sensitivity trade-off.
Produced by fungi during fermentation (including in sake brewing), kojic acid chelates the copper that the pigment enzyme tyrosinase needs to function, slowing melanin production.
Trials used 1–4%; the EU now restricts cosmetic use to 1% (SCCS-reviewed).
Trial-supported brightening, usually as a co-star
Randomized trials — often combining kojic acid with hydroquinone or glycolic acid — show meaningful melasma improvement, with kojic-containing arms outperforming those without. Solo evidence at today's 1% cap is thinner; expect it to assist rather than lead.
Anchored to regulatory assessments — not hazard lists. Dose makes the poison; these are the conclusions at real-world cosmetic use.
SCCS deemed kojic acid safe at up to 1% in face products (the current EU limit). Contact sensitization is documented with long-term higher-strength use — patch-test if you're reactive.
Source →