What is Kojic Acid?

Kojic acid is made from certain types of fungi, or as a byproduct of fermentation such as with Japanese sake, soy sauce and rice wine. Kojic acid prevents the formation of tyrosine, the amino acid needed to produce melanin. Melanin is the pigment that gives your skin, hair, and eyes color. Since Kojic acid inhibits the production of melanin, it can have a lightening effect.

What Does Kojic Acid Treat?

Topically, kojic acid can be used to treat several skin conditions. It is primarily used to lighten visible sun damage, scars, or age spots. Additionally, kojic acid has some antimicrobial properties making it useful in treating acne and lightening scars from acne.

Due to its antifungal properties, it can be added to other products to help increase its effectiveness. This is useful for treating fungal infections of the skin such as athlete’s foot, ringworm, yeast infection and candidiasis.

How to Use Kojic Acid

Kojic acid comes in many types of products such as creams, cleansers, soaps, serums, face masks, and even powders. These products are most often used on the face and hands but can be used on all non-sensitive areas of the body.

Be sure to follow the directions as each form will require different instructions. For example, some forms of kojic acid like creams and serums are meant to be left on the skin whereas others (like cleansers) need to be washed off immediately.

Precautions and Side Effects

Kojic acid is considered safe to use but some people may experience side effects. The most common side effect is contact dermatitis which can manifest as redness, itchiness, irritation, rashes, swollen skin, or discomfort and pain. This most often occurs in individuals with sensitive skin, or people using a higher concentration of kojic acid. If you have a reaction, discontinue use.

When used long-term, kojic acid may make you more sensitive to sunlight, meaning you have an increased risk of sunburn. Be mindful of sun exposure and protect your skin with sunscreen and protective clothing. You should never use kojic acid on broken or damaged skin.