Kojic Acid

Kojic acid is a naturally occurring fungal metabolite produced from species of Asperigillus, Acetobacter, and Penicillum. Kojic acid works by inhibiting the tyrozinase enzyme, thereby preventing the conversion of dopa to melanin.

Kojic acid containing products are used specifically as topical therapies for disorders of hyperpigmentation such as melasma, lengtigines, and postinflammatory hyperpigmentation. (They are inffective for lightening of total body complexion)

Kojic acid has been used in concentrations of 2�4% either alone or in combination with 2% hydroquinone and alpha-hydroxy acid gel base. Significant side effects include irritation and contact dermatitis. Treatment may take months to resolve.

Animal testing has shown that kojic acid can cause embryotoxicity, systemic toxicity in the liver and kidney, and cancer of the liver.

There is inadequate evidence that kojic acid is carcinogenic in humans. Currently, kojic acid has been banned as a cosmetic ingredient in Japan, Korea and Switzerland because of its mutagenicity concerns.