Kojic Acid

* A whitening agent created from fungi

* An irritant

Functions:

Kojic Acid is a fungal metabolic product, produced by several species of fungi, that inhibits the rate-limiting, essential enzyme in the biosynthesis of the skin pigment melanin. Kojic Acid is used in whitening products because of this ability to limit melanin production and is often seen as a skin-lightening gel. It inhibits the rate-limiting, essential enzyme in the biosynthesis of the skin pigment melanin(Wikipedia).

When used as a skin whitening agent, kojic acid is generally formulated at a concentration of 1% in leave-on creams. However, products containing Kojic acid can be find on the market at concentrations higher than 1%.

In a 1982 study done in Tokyo, Japan, 66 patients were treated with Kojic Acid over an average of one year. 95% saw improvement in the whitening of their skin. In 1994, another study was done by the same independent scientists, and out of 131 patients, 81% saw remarkable improvement. However, Kojic Acid is considered a severe irritant. There are multiple skin-whitening alternatives to Kojic Acid, including: Asafetida, Alpha Arbutin, Gamma Oryzanol, and Tetrahydrocurcuminoids.

Kojic Acid is also consumed widely in the Japanese diet, with the belief that it is an internal health promoter; it scavenges reactive oxygen species released excessively from cells or generated in tissue or blood, according to an article entitled "Skin Lightening and Depigmenting Agents," published by dermatologists at the University of Pennsylvania Medical Center.

Safety Measures/Side Effects:

Kojic acid has is highly sensitizing and may cause irritant contact dermatitis, even in its typical concentration levels below 4%. It's also been shown to cause carcinogenic and other mutations in mice and rats according to studies cited  by the Environmental Working Group. However, the International Agency for Research on Cancer (IARC) says it is "not classifiable/not likely to be human carcinogen". Studies on rats showed it accumulate in the blood with prolonged use. In 2008, the European Union concluded that “data support the conclusion, that skin penetration in rats and humans is considerable” and “the use of Kojic acid at a maximum concentration of 1.0% in skin care formulations poses a risk to the health of the consumer” (source)

The industry body, the CIR, says: "While some animal data suggested tumor promotion and weak carcinogenicity, kojic acid is slowly absorbed into the circulation from human skin and likely would not reach the threshold at which these effects were seen." It adds that skin whitening effects are not seen at concentrations below 1%.

Recommended Products w/ Kojic Acid:

Nutra Lift Dark Spot Fade Gel, PRESCRIBEDsolutions A Bolt of Lightening, Biotica Spot Whitening Serum