Kojic acid is used in skin care formulations to lighten the skin, like another agent, hydroquinone. However, while hydroquinone works by inhibiting the activity of tyrosinase by acting as a melanocyte cytotoxic inhibitor and by increasing the cytotoxicity of melanocytes (melanin-producing cells), kojic acid lightens the skin solely by suppressing tyrosinase activity (by inhibiting catecholase activity of tyrosinase) in a non-traditional fashion. Kojic acid is worldwide known for its skin-lightening abilities, and is commonly used in topical formulations to treat dark spots and pigmentation.
Kojic acid is a by-product in the fermentation process of malting rice for use in the manufacture of sake, the Japanese rice wine. There is definitely convincing research, both in vitro and in vivo, and also 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).
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. Kojic Acid is also presented by Alta Care as a roller or as glass ampoules. The glass ampoules can be sold individually at €9.80 per ampoule. Dermastir rollers cost €12 per roller.
Directions of use
Distribute the whitening serum using the roller ball directly on the pigmented parts of the skin. Do not massage in after application. Kogic acid ampoules are used to compliment the Dermastir rollers when more intensive action is needed.
Normal programme: apply once daily
Intensive programme: apply 3-4 times daily
Warnings: do not expose yourself to the sun. Avoid contact with eyes and if that happens, rinse with water.