How kojic acid benefits your complexion

The mushroom-derived ingredient that’s a dark spot corrector

You know you shouldn’t pick at pimples, and you try to keep up careful SPF application, but life happens and so does hyperpigmentation. Dark spots are easy to get and can be frustratingly difficult to resolve. 

While there’s no such thing as a magic eraser for dark spots, we can turn to a number of skincare ingredients that help fade discoloration. At Agency, we reach for kojic acid again and again. Here, we’ll tell you why and exactly how kojic acid works.

What is kojic acid?

Kojic acid is a naturally derived antioxidant that works to brighten the skin, especially areas of hyperpigmentation. It’s created by a fungus called koji that’s used in Japan to create fermented foods like soy sauce, miso, and sake. 1 Plus, the ingredient is found in other fungi, including shiitake mushrooms. 

What does kojic acid do to your skin?

While we love eating all the tasty foods kojic acid helps make, we’re here to talk about applying it to your skin. As a topical skincare ingredient, kojic acid can help fade dark spots and create a more even skin tone. 

Whether you have sun spots, melasma, or post-inflammatory hyperpigmentation marks left behind by acne, kojic acid can help. The ingredient inhibits an enzyme called tyrosinase 2 that’s needed to produce melanin, the pigment that gives your skin its color. When melanin can’t be produced, it can’t gather into those pesky patches of hyperpigmentation—simple as that. 

Where can you get kojic acid?

Your Agency dermatology provider can include kojic acid in your customized Dark Spot Formula. Your personalized formula will target your specific hyperpigmentation concerns and may pair up kojic acid with other ingredients proven to correct dark spots. It has been shown to work especially well with hydroquinone 3 as a depigmenting solution, which can be prescribed at stronger concentrations than available over-the-counter, as appropriate for your skin type and tone. 

Otherwise, this skin brightener features in a number of over-the-counter skincare products, like kojic acid soaps, serums, and creams.

Is kojic acid safe?

Kojic acid is generally considered a safe option (in concentrations ranging from 1% to 4% 4) for treating skin discoloration, but it can be sensitizing5 to some skin. Your Dark Spot Formula will be created to minimize the risk of irritation, but we have a handy guide with tips for dealing with irritation in case you do experience side effects like redness, itching, and burning.

Plus, it can make your skin more sensitive to the sun, 6 so it’s essential to make a daily habit of sunscreen while using kojic acid products. Bonus: Protecting your skin from UV rays helps prevent hyperpigmentation too!

Want to know more about your Dark Spot Formula?

You know your skin—we’re here to help you know your skincare. Our team of dermatology experts has helped create guides to each of the hyperpigmentation-targeting ingredients in your Dark Spot Formula. 

Learn how hydroquinone and azelaic acid also help even out your skin tone.



1. Majid Saeedi, et al. Kojic Acid Applications in Cosmetic and Pharmaceutical Preparations. Biomedicine & Pharmacotherapy. (February 2019).

2. Debabrata Bandyopadhyay.  Topical Treatment of Melasma. Indian Journal of Dermatology. (October–December 2009).

3. Kirti S. Deo, et al.  Kojic Acid vis-a-vis Its Combinations with Hydroquinone and Betamethasone Valerate in Melasma: A Randomized, Single Blind, Comparative Study of Efficacy and Safety. Indian Journal of Dermatology. (July–August 2013).

4. Debabrata Bandyopadhyay. Topical Treatment of Melasma. (Ibid.)

5. Mikio Nakagawa, et al. Contact Allergy to Kojic Acid in Skin Care Products. Contact Dermatitis. (January 1995).

6. Majid Saeedi, et al.  Kojic Acid Applications in Cosmetic and Pharmaceutical Preparations. Ibid.