What is Kojic Acid?

Products with the term “acid” in their name often don’t sound very inviting.  After all, substances which are quite acidic can be dangerous or corrosive.  However, several ingredients deemed acids have made their way into popular skincare products, and in truth, they make for very effective products.  You’ve probably even heard of some of them.  Glycolic acid, for example, is used in many serums for exfoliation purposes.  And, mandelic acid is a relatively gentle chemical peel agent.  Both of these acids help reveal younger, healthier skin under the old layer.  But, what is kojic acid? 

Kojic acid is used mostly as a brightening ingredient in skincare products.  Rather than penetrate your skin to produce peeling, as glycolic and mandelic acids do, kojic acid penetrates the skin to stop the production of melanin.  And, since melanin is the dark pigment that causes your skin to change colors as you age or get tan, this can keep skin brighter as you get older.  This humble ingredient is very natural and comes from mushrooms.  It also is a byproduct of sake, which is a Japanese wine made from fermented rice.  It is used as a color preservative because it prevents natural colors from changing due to oxidizing or age.  For example, it is used on cut fruits to keep them from browning.  But, it may be even more useful on skin.

Cosmetic Uses for Kojic Acid

Skin naturally changes color over time.  This can be a result of natural processes or it can be due to photoaging.  The skin condition melisma, which is the appearance of brown or gray splotches or patches of skin on the face, is one of the reasons why many women reach for skin brightening creams and serums, many of which contain kojic acid.  People with skin-darkening acne can use kojic acid for its antibacterial and antifungal properties in addition to its brightening effects.  Others use kojic acid products to lessen the appearance of dark spots due to age.  Those who get hyperpigmentation in general can benefit from using kojic acid.  This, of course, does not include lightening skin that is naturally dark or pigmented all the time.

Dangers of Kojic Acid

The reason that kojic acid shouldn’t be used to lighten skin that is naturally dark is because kojic acid is really only a temporary treatment.  In fact, it can be damaging to skin if used over a long period of time.  For example, some people may begin to experience an allergic reaction to kojic acid, even if they didn’t have one previously.  This allergic reaction may cause discomfort as well as visible changes.  Those who have a severe reaction to kojic acid may even notice a semi-permanent, unnatural-looking bluish tint to their skin.  And, long-term use may also impact internal functions, such as the thyroid processes.  If you are concerned about using kojic acid, be sure to ask your dermatologist for her opinion first.  Otherwise, kojic acid should be safe for short-term use, and may solve a variety of skin problems.