Kojic Acid Is the Hyperpigmentation-Fighting Ingredient Your Skin-Care Routine's Missing

At this point in the game, you're probably familiar with the skin-care benefits of various acids. (If not, the simplified explanation is that they exfoliate skin, prevent clogged pores, and help to even out tone and texture.) You may even have a few personal favorite acid-containing products in your stash that you reach for when your skin is looking a bit dull. There's certainly no shortage of options to choose from, meaning you can select an exfoliating product based on your skin type and concerns. One lesser-known acid that's finally getting its due for its ability to brighten all skin tones safely? Kojic acid.

What Is Kojic Acid?

Kojic acid is a compound that was first discovered in Japan in the early 1900s within a fungus growing on steamed rice ("koji" being the name of the fungus). Kojic acid is often derived from various fermented foods such as mushrooms, sake, and soy sauce, according to Howard Sobel, M.D., dermatologist and founder of Sobel Skin. Unlike AHAs such as mandelic, lactic, and glycolic acids, kojic acid evens out skin tone by halting excess melanin production rather than exfoliating dead skin at the surface, explains Dr. Sobel. (

What Are the Benefits of Using Kojic Acid for Skin Care?

Kojic acid's ability to stop excess melanin production in its tracks (specifically by inhibiting the melanin-producing amino acid, tyrosine) is at the root of its popularity in products intended to correct dark spots and hyperpigmentation, says Dr. Sobel. (Refresher: Hyperpigmentation is when an overproduction of melanin — natural pigments — causes one area of skin to become darker than the surrounding areas.) It's important to note that kojic acid targets existing and future dark spots and won't lighten your overall skin tone, so you can proceed to use the product in all-over products such as facial cleansers and serums, says Dr. Sobel.

"Kojic Acid works well to lighten dark spots and hyperpigmentation from UV damage and acne scarring," says Dr. Sobel. "...It is an exceptional skin brightener because it works on all skin tones, unlike more aggressive lightening ingredients." For example, hydroquinone, a popular skin-lightening ingredient, is controversial since it is notoriously irritating, may cause discoloration, and shows possible carcinogenicity (read: may produce cancer). Kojic acid is considered safer and generally more gentle.

Also worth noting, while kojic acid doesn't produce instant gratification, it comes close. "Kojic acid works rather quickly, within two to three weeks, with full results in two to three months," says Dr. Sobel.

Who Is Kojic Acid Best For?

Kojic acid is suitable for all skin types, but sensitive skin may be susceptible to irritation or redness, says Dr. Sobel. To avoid any reactions, it can be helpful to patch test a product with kojic acid before using it on your face. Those who experience spots resulting from sun damage, red marks, acne scarring, or melasma stand to gain the most from using kojic acid. (

How to Add Kojic Acid to Your Skin-Care Routine

You can find kojic acid in various types of skin-care products ranging from cleansers to serums. To get the most out of the ingredient, Dr. Sobel suggests going with a serum containing kojic acid in a one to two percent concentration.As far as how often to use kojic acid, start with two to three times per week and build up your tolerance to daily as needed, advises Dr. Sobel.

Though it may be tempting to load up your skin-care routine with kojic acid from start to finish, you should instead start slow by adding one kojic acid-based product to your routine (such as an active serum), says Dr. Sobel. You should also refrain from using kojic acid with retinol, which puts your skin at risk of irritation and sensitivity, he advises. On that note, wearing sunscreen is essential to protect your newly evened skin tone and maintain the brightening effects of implementing kojic acid into your skincare routine, says Dr. Sobel. When using kojic acid, it's important to also prioritize hydration to prevent potential sensitivity or redness, says Dr. Sobel. Incorporating ingredients such as hyaluronic acid or glycerin into your skin-care routine can help.

If you haven't had the greatest luck finding the right products to brighten dark spots and hyperpigmentation, kojic acid may be the missing link in your skin-care routine.