By-product of the fermentation process of malting rice for use in the manufacture of sake, Japanese rice wine. There is definitely convincing research, both in vitro and in vivo and in animal studies, showing that kojic acid is effective for inhibiting melanin production (Sources: Biological and Pharmaceutical Bulletin, August 2002, pages 1045–1048; Analytical Biochemistry, June 2002, pages 260–268; Cellular Signaling, September 2002, pages 779–785; American Journal of Clinical Dermatology, September–October 2000, pages 261–268; and Archives of Pharmacal Research, August 2001, pages 307–311). Both glycolic acid and kojic acid, as well as glycolic acid with hydroquinone, are highly effective in reducing the pigment in melasma patients (Source: Dermatological Surgery, May 1996, pages 443–447). So why aren’t there more products available containing kojic acid? Kojic acid is an extremely unstable ingredient in cosmetic formulations. Upon exposure to air or sunlight it turns a strange shade of brown and loses its efficacy. Many cosmetics companies use kojic dipalmitate as an alternative because it is far more stable in formulations. However, there is no research showing that kojic dipalmitate is as effective as kojic acid, though it is a good antioxidant. There is a small amount of research showing that kojic acid is a skin irritant (Source: www.emedicine.com, “Skin Lightening/Depigmenting Agents,” November 5, 2001).
«Back to Ingredient Dictionary