Byproduct of Aspergillus fungal fermentation. Chelates copper, inhibiting tyrosinase. One of the early depigmenting agents with proven efficacy.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
Several RCTs confirmed efficacy in melasma and post-inflammatory hyperpigmentation. A 2013 meta-analysis showed comparable efficacy to hydroquinone but a higher rate of contact dermatitis. In Europe, maximum concentration in cosmetics is restricted to 1%.
1–4%
Kojic Acid is a by-product of Aspergillus oryzae fungal fermentation (the same fungus used to produce sake and soy sauce). One of the early depigmenting agents with proven efficacy, used in Japan since the 1970s. Mechanism. Chelates copper (Cu²⁺) – cofactor of tyrosinase, the key enzyme of melanin synthesis. Without copper tyrosinase fails, melanin synthesis decreases. Additionally scavenges free radicals (antioxidant). Where applied. Depigmenting serums and creams, masks, melasma and post-inflammatory hyperpigmentation products (1-4%). In Spain in SVR Clairial, Sesderma Azelac Ru, Mesoestetic Cosmelan Maintenance, ISDIN K-OX. Often combined with other depigmenters (arbutin, niacinamide, azelaic acid) for synergy. Evidence base. Garcia 1996, Lim 1999 – RCTs with 2-4% kojic acid, efficacy comparable to hydroquinone 2% in melasma but with better tolerability and no ochronosis risk. Cochrane 2014 – depigmenting combinations with kojic acid effective in melasma. Safety. CIR rated kojic acid safe at cosmetic concentrations up to 2% (2010, re-evaluated 2018). EU SCCS confirmed safety up to 1% in leave-on. Irritation and contact dermatitis reported in 5-10% of patients, especially at high concentrations. Isolated allergic sensitization described. Pregnancy – no proven teratogenicity data, but few direct studies. EU SCCS rates as "acceptable with caution". Lactation – use with caution. Pregnancy alternatives: azelaic acid 15-20%, niacinamide 5%, tranexamic acid.
Irritation potential
MediumAllergen risk
ModeratePregnancy
CautionFor sensitive skin
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Kojic Acid should be used with caution during pregnancy. Consulting a dermatologist or OB-GYN is advisable.
Kojic Acid suits: normal, combination, oily. Use with caution in: sensitive, dry.
Kojic Acid has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
Byproduct of Aspergillus fungal fermentation.
The INCI name is Kojic Acid. It may also appear as: Коевая кислота.
Published: · updated:
Risk of contact dermatitis with prolonged use is higher than average.
Suitable for
Use with caution
1–4%