Kojic Acid for Acne scars
Kojic Acid is a chemical preparation used by the cosmetic industry to perserve color of substances. It is originally produced by several different species of mold and is also a by-product in the process of making Japanese sake, or rice wine. More recently it has been sold over the counter as a skin whitening agent to help reduce the appearance of brown aging spots and acne scar tissue.
Kojic acid is a tyrosinase inhibitor, which means it will inhibit or stop the production of melanin. Scar tissue and brown spots have a higher concentration of melanin, which provides the unique color. Melanin is also the chemical in your skin which makes you tan when you’re out in the sun. Researchers have investigated the use of this chemical to prevent the discoloration of meat, vegetables and sea food, as well as a preservative for fats and oils in cosmetics.
Research pubished in the Journal of biomedical Biotechnology found that Kojic acid esters, or the acid that was produced through esterification of kojic acid, was less cytotoxic [toxic to the cells] at a higher dosage level. The researchers found that for skin whitening process it was safer to use the ester formation of the acid and for potential depigmentation of hyperpigmented areas on the skin. (1) Therefore the ester formulation was believed to be safer to reduce the appearance of brown pigmentation on the skin.
One of the dangers of using Kojic acid on the skin is sensitization and increasing sensitivity, reducing the amount of melanin in the skin and therefore the natural protection against the sun’s UV rays. There have also been conflicting information published about the safety of using Kojic acid on the skin and whether it is carcinogenic, or will trigger cancer. Melanoma, or skin cancer originating in the melanocyte cells of the body, is one of the most aggressive types of cancer.
The body has melanocytes in the skin, bowel and the eye. But it is the skin that has the most melanocytes which are responsible for the darkening of your skin when you are in the sun, your beauty marks and age spots. Because Kojic acid works directly on the production of melanin from the melanocytes more research is needed to determine the long term effects of using this lightening agent on the skin in high concentrations.
At this time, concentrations of 1% have been found to pose a risk to the user. (2)
(1) Journal of Biomedicine and Biotechnology: Depgimenting Effect of Kojic Acid Esters in Hyperpigmented B16F1 Melanoma Cells
(2) Directorate-General for Health and Consumers: Scientific Committee on Consumer Products
Journal of the American Chemical Society: The Production of Kojic Acid by Aspergillus Flavus
Monographs: Kojic Acid
SkinStore: Kojic Acid