This particular acid is the by-product of fungi, primarily Aspergillus, used in Japan to make rice wine, soy sauce, and miso! Fortunately, kojic acid is extremely useful in skincare products!
Kojic acid inhibits the production of tyrosinase, the enzyme required for the production of melanin. That means its a natural skin lightening agent that inhibits the formation of new pigment. Therefore, it is effective in combatting melasma, hyperpigmentation, age spots, and discoloration. We like suggesting kojic acid as a substitute for hydroquinone for these effects. While irritating to a tiny minority, this ingredient is significantly more gentle and safe on sensitive skin types.
A lot of companies refer to this as a "skin lightening effect" or "whitening. These terms can be a little misleading: lightening, brightening, and whitening aren't about changing your actual skin tone. Think of it instead as "evening" or "leveling" out skin tone by getting rid of dark spots that don't match the rest of your skin color. That's why you don't see us referring to this type of process as "whitening." We find that language excludes people who might actually want this effect in their skincare products!
There's one catch: as with most acids in skincare products, kojic acid makes can make you more prone to sunburns as a side effect. Please apply sunscreen with an adequate SPF when regularly using skincare products with kojic acid. We recommend sunscreen regardless, so why not protect yourself?
However, kojic acid is also a powerful antioxidant that provides significant protective effects against UV damage. It scavenges and neutralizes the free radicals that cause the signs of aging and shields against oxidative stress. Pair it with other antioxidants, like vitamin C, for maximum effect.
Kojic acid has an additional strength that takes the antioxidant factor to the next level. It’s an iron-chelating agent. Your skin contains a fair amount of iron. That's great, except when exposed to UV radiation, iron gets released to cause photo-damage and accelerate aging. Chelation is the process of binding those particles together to avoid that. This makes kojic acid an anti-aging champion.
The cherry on top of it all, kojic acid has anti-bacterial properties too! It helps remove blemishes and combats acne to keep skin clear and radiant. Talk about being an overachiever.