Plus, how to use it safely.
By Sabrina Talbert Sep 18, 2025
If you live on TikTok these days, odds are you’ve heard about kojic acid. What first started as a tip from an influencer about using kojic acid soaps to lighten underarms has turned into a full-blown craze. But with all the hype around kojic acid products, you may be wondering what it is in the first place.
You wouldn’t be alone.
While some people seem to have great results with kojic acid (think fewer dark spots on the face or an improvement in uneven skin texture), others have been vocal about the not-so-great side effects. If you’ve stumbled across the good and bad of kojic acid and are hoping to get some questions answered, you’re in luck. Women’s Health chatted with three top dermatologists to share everything there is to know about the popular ingredient, including where it comes from, the benefits, risks, how to know it’s for you, and arguably most importantly, how to use it correctly.
Below, you can also find product recommendations and some helpful alternatives in case kojic acid isn’t the right fit for you.
What is kojic acid?
Kojic acid is a skin-lightening ingredient that comes from mushrooms. “It is a natural byproduct of a fermentation process and has been shown to help regulate pigment production,” says Aya Ahram, MD, a board-certified dermatologist specializing in medical, cosmetic, and surgical dermatology. Kojic acid also has anti-aging and antioxidant properties, says Navin S. Arora, MD, a board-certified dermatologist and founder of Borealis Dermatology.
What are the benefits of kojic acid.
Skin lightening: Kojic acid blocks tyrosinase, an enzyme that controls the production of melanin. As a result, you may notice reduced pigmentation and dark spots for a more even skin tone, says Dr. Arora
Anti-aging: Kojic acid has antioxidants that “reduce free radical damage to help prevent elastin and collagen breakdown from stress, pollution, and sun,” says Dr. Ahram. This can reduce symptoms of premature aging such as fine lines and wrinkles.
Treatment of melasma: Melasma causes hyperpigmentation, and is more common in darker skin tones. “Not just any “lightening cream” can treat melasma, which is why kojic acid is such a great option,” says Dr. Arora.
What kinds of products contain kojic acid?
Kojic acid can be found in various products, including serums, moisturizers, creams, peel pads, and soaps. Serums are highly concentrated and penetrate deep into the skin, while moisturizers and creams boost hydration, says Dr. Arora. Kojic acid soaps are sometimes used to lighten skin and treat dark spots and acne scars. “No single formulation is universally superior,” he says. “The effectiveness can depend on the concentration, frequency of use, an individual’s skin type, and the condition being treated.
What skin types can use kojic acid?
Kojic acid can be most helpful to people with hyperpigmentation or melasma, says Dr. Arora. At the same time, those with normal to oily skin can find it especially beneficial. That said, sensitive or dry skin types are more
likely to find kojic acid irritating. In this case, he recommends “using a lower percentage initially and applying to a test spot for a few nights initially,” he says. Dr. Ahram adds that in general, it’s best practice to not use kojic acid daily to avoid over-exfoliating your skin.
Side effects of kojic acid
Dr. Ahram suggests using products with one percent of kojic acid or less. Overusing or using a higher percentage of it can lead to some side effects worth keeping in mind such as:
- Skin irritation
- Redness
- Itching
- Flaking
- Allergic contact dermatitis
If you’re concerned about how kojic acid will affect your skin long-term, Dr. Arora advises limiting your use so that you take a month off of using it every three months.
How to use kojic acid
If you’re starting to introduce kojic acid into your routine, try using it every other day to see how your skin reacts, says Dr. Arora. From there, you can increase to using it daily unless you’re using it with other exfoliating acids. In this instance, Dr. Ahram suggests only using it two to three times a week to avoid irritation.
Another pro tip: use an SPF. “Always apply sunscreen during the day, as kojic acid can increase sun sensitivity,” says Dr. Arora. Dr.Camp adds that sunlight could potentially reverse the benefits you achieve with skin brightening products.
What are some kojic acid alternatives?
If kojic acid is too strong for your skin, there are a few alternatives worth looking into. Vitamin C, for example, reduces pigmentation and boosts collagen production, says Dr. Arora. Meanwhile, something like niacinamide lightens dark spots by preventing melanin from transferring to the skin’s surface. Dr. Ahram adds that arbutin and licorice root extract can help with antioxidant activity and regulation of pigment production.
Finally, Dr. Camp recommends azelaic acid, retinol, glycolic acid, and hydroquinone. However, you’ll need a prescription from your doctor for the latter option. if you’re unsure if kojic acid or any alternative is right for you, check in with your doctor to determine which is best for your needs and preferences.
