Kojic acid is a whitening agent unique to Japan since ancient times. It was discovered because the hands of people who handle kojic acid in the sake brewing process are white and beautiful. Kojic acid suppresses the action of tyrosinase, an enzyme necessary for the synthesis of melanin pigment, thereby reducing stains and pigmentation.

Experiments have shown that after an average of about 18 months of use, 88% of people’s spots fade to some degree. It is also prescribed for those who are too irritated by hydroquinone. It also has an anti-glycation effect and is recommended for those who are concerned about yellowing.