Rice alone has several properties that benefit skin (which I’ll explain in my Rice Extract description), but if you ferment that rice, you get a whole new advantage. Rice ferment, better known as sake, produces Kojic Acid as a by-product. Kojic acid is an antibacterial, antifungal substance derived from mushrooms. It is a skin-lightening agent at concentrations of 4%, and functions similarly to hydroquinone in that it inhibits melanin production, but it’s less likely than hydroquinone to cause irritation. I’m not sure how much Kojic acid present in this particular formula, however.
I’ve seen a few concerns voiced about the safety of Kojic acid. Here are the facts: There were a few studies done on rodents that showed Kojic acid to be a potential carcinogen when taken orally in large doses. Subsequently, a few more studies were done that actually showed Kojic acid to be an antioxidant, and to have cancer prevention properties. Japan is currently conducting more Kojic acid studies in an effort to come to a more definitive conclusion, but since none of the studies showed it to be harmful when applied topically, it’s considered a safe cosmetic ingredient by Japan, Korea, and the US. It has been banned in Switzerland. Additionally, it’s worth noting that Kojic acid occurs naturally as a constituent in all soy ferment based foods, such as miso and soy sauce