What Kojic Acid Can Do for Your Skin

Medically Reviewed by Dan Brennan, MD on September 04, 2021
3 min read

You may see the word "acid" and think of something painful. Don't worry — kojic acid is good for your skin!

Kojic acid is quickly growing in popularity. Notably, it's starting to replace hydroquinone in many bleaching agents. For example, you can find kojic acid in products used to bleach skin and whiten teeth.  ‌

Kojic acid is a natural derivative of a fermented fungus. Several types of fungi produce kojic acid, but some produce more than others. ‌

Other potential benefits. Kojic acid isn't just a whitening agent. You may see kojic acid used in: 

  • Insecticides and pesticides
  • Fungicides
  • Anti-fungal and anti-bacterial drugs
  • Painkillers
  • Anti-inflammation drugs

The list goes on! Researchers are still learning the benefits of kojic acid and its diverse applications. 

Kojic acid inhibits your body's melanin production. Melanin is a pigment that adds brown color to your skin, hair, eyes, and more. ‌

By inhibiting your melanin production, kojic acid creates a more consistent skin tone in the treated areas. As a result, splotchy areas on your skin become less defined until they match the surrounding skin. ‌

Bleaching agents. Kojic acid's properties allow it to be a bleaching agent when used in creams, gels, and other cosmetics. Kojic acid is similar to a chemical called hydroquinone. They are both effective treatments for hyperpigmentation. 

Treatment with kojic acid isn't immediate. For significant improvement, you'll need to use a kojic acid cosmetic for up to three months in some cases.

Hyperpigmentation describes dark spots on your skin caused by excessive melanin. It's typically nothing to worry about, but the spots may affect your appearance. 

Hyperpigmentation is common. For many adults, hyperpigmentation comes from:

  • Excessive sun exposure or artificial blue light
  • A medical condition
  • Hormone changes
  • Severe rashes

Pigmented birthmarks and moles are types of hyperpigmentation. While these typically appear at birth and aren't dangerous, they can pose certain health risks by turning into cancer later in life. ‌

Kojic acid isn't just for large areas of hyperpigmentation. You can use kojic acid to treat sun damage, spots from aging, and scarring. ‌

Avoid hyperpigmentation. If you have hyperpigmentation or are considering kojic acid treatment, the first step is to protect yourself from the sun. Sun exposure can worsen hyperpigmentation.‌

Melasma. A common skin condition that can cause hyperpigmentation is melasma. It leads to the development of brown patches, most commonly on your face. This is caused by the color-producing cells working too much and producing dark spots on the skin. ‌

Women and people of color are more likely to get melasma. In addition, women are more susceptible to melasma during pregnancy because of the drastic changes in hormones. This melasma or " pregnancy mask" may fade after pregnancy.

Kojic acid has few known risks, and observed side effects are rare. ‌

One potential risk is contact dermatitis. Concentrations of kojic acid higher than 1% are more likely to cause contact dermatitis. Symptoms include:

  • Skin irritation
  • Rashes
  • Skin inflammation
  • Itchy skin
  • Pain

Contact dermatitis results from something irritating your skin, something that causes an allergic reaction, or both.  Contact dermatitis is common with most cosmetics, not just kojic acid.  

Increased skin sensitivity, another possible side effect, can lead to a higher risk of sunburn. Less melanin in your skin makes you more susceptible to sunburn. 

If kojic acid treatment makes your skin more sensitive, you'll need to take extra care of your skin in terms of sun exposure. Use sunscreen frequently, wear wide-brimmed hats and clothes with coverage, and avoid prolonged sun exposure.

If you're dealing with hyperpigmentation, scarring, or age spots, kojic acid cosmetics are a great place to start. ‌

Talk to your doctor about treatment options for hyperpigmentation so that they can recommend an ideal treatment option. Alternatives to kojic acid include:

  • Retinols that exfoliate your skin and inhibit skin pigments
  • Chemical peels that remove surface layers of skin (can potentially worsen hyperpigmentation)
  • Prescription medications
  • Laser therapies (can be temporary)

The chemical hydroquinone is the predecessor to kojic acid. It's deemed safe and accomplishes the same goal as kojic acid. If you have side effects with kojic acid, consider hydroquinone instead. 

You can buy kojic acid cosmetics from your local pharmacies and online. Before you start a treatment plan, talk to your doctor to avoid complications.