Kojic Acid Is the Dermatologist-Loved Ingredient For Fading Dark Spots

You likely already know about and use glycolic and salicylic acids in your beauty routine. Still, another somewhat under-the-radar acid deserves time in the skincare hero spotlight—particularly if your goal is a brighter, more even complexion. We're talking about kojic acid—a naturally derived skincare ingredient that comes from the superfood mushrooms.

Kojic acid is excellent at fading hyperpigmentation and discoloration (aka dark spots). It works well on its own *and* when paired with other brightening ingredients. Plus, it also acts as an antioxidant and has anti-inflammatory properties. To help you incorporate this ingredient into your current skincare routine, we asked top dermatologists Y. Claire Chang, MD, Dhaval Bhanusali, MD, and Rachel Nazarian, MD, to give us the lowdown on all things kojic acid.

Read on to learn how the experts recommend using it to say goodbye to dark spots for good.

What is Kojic Acid?

As we mentioned, mushrooms are the source of kojic acid, a byproduct of various fungi that also occurs due to the fermentation of certain Asian foods, such as soy sauce and rice wine, explains Chang.

How Does It Work?

"Unlike other acids that work by dissolving the bonds between the cells and exfoliating the skin, kojic acid works by inhibiting pigment production," she says. It also works well when paired with other skin-lightening ingredients (namely, the gold standard hydroquinone, most commonly prescribed by derms).

Dermatologists often combine it with hydroquinone for a synergistic, prescription-strength lightening agent, notes Bhanusali. But on the flip side, it works well on its own, too, and is a great alternative for those who can't tolerate or don't want to use the more potent hydroquinone. "It’s also less likely to cause an overly-white appearance of the skin, making it a good option for people with darker complexions who'd be more likely to [experience extreme lightening] from using other ingredients," says Nazarian.

Benefits of Kojic Acid for Skin

Spot-fading and skin brightening is the name of the game for this ingredient, though it does have a few other standout qualities, such as:

• Inhibits the production of melanin in the skin: The pathway that leads to excess melanin or pigment (in other words, a dark spot) is complex, but at the heart of the matter is an enzyme known as tyrosinase. Kojic acid blocks the UV activation of tyrosinase, thereby limiting melanin production. This means it can help lighten existing sunspots and photodamage, fade the dark marks left from acne scarring or after a pimple, and even improve melasma, notes Chang.
• Acts as an antioxidant: Kojic acid can help scavenge and counteract skin-damaging free radicals caused by exposure to UV damage and pollution. This not only helps improve overall skin tone as well but also makes it a good general anti-aging ingredient, says Nazarian.
• Has anti-inflammatory and anti-viral properties: Unlike many other acids, it also has these unique characteristics, though they're secondary to the skin-lightening benefits.

What Products Contain Kojic Acid?

Kojic acid can be found in numerous cosmetic formulations, including powders, serums, masks, creams, cleansers, and soaps.

Is Kojic Acid Safe For All Skin Types?

According to the experts, kojic acid is safe for most skin types. Anyone seeking to improve the look of discoloration caused by sun damage, melasma, or post-inflammatory hyperpigmentation that occurs after a blemish would benefit from kojic acid most, says Chang. Bhanusali adds that it's also a good option for those who want to avoid or can't tolerate hydroquinone, one of the most often-used skin-brightening ingredients.

Potential Side Effects

"Generally speaking, kojic acid is better tolerated than most acids, but an allergy or irritation is certainly possible," points out Bhanusali. A red rash, itching, irritation, and burning are the most common side effects, adds Chang, though these are typically uncommon if you're using lower concentrations of the ingredient (and most over-the-counter products do contain a lower concentration). If irritation persists, consult with a board-certified dermatologist.

How to Use It

If your skin is super sensitive, Nazarian recommends not using it daily at first; instead, work kojic acid-based products into your regimen just once or twice per week to ensure that your skin can tolerate the ingredient. Also worth noting: "When used over time, kojic acid may also make your skin more susceptible to the sun," says Chang. Using sunscreen daily is always important, but even more so when kojic acid is in your skincare mix.

Alternative Ingredients

There are numerous ingredients on the market other than kojic acid that may help fade hyperpigmentation, dark spots, and acne scares, including:

• Glycolic acid is an alpha-hydroxy acid that loosens bonds between dead skin cells. It helps stimulate collagen production and acts as a humectant, attracting moisture to the skin.
• Retinol is a vitamin A derivative that helps promote skin cell turnover and boosts collagen production. In doing so, it helps even skin tone and texture, helping to reduce discoloration.
• Hydroquinone is a topical skin treatment that lightens hyperpigmentation, age spots, and freckles while evening out skin tone.
• Arbutin is a natural derivative of hydroquinone that fades dark spots, hyperpigmentation, and acne scars.
• Vitamin C helps fade dark spots and boosts sunscreen efficacy, helping prevent future dark spot formation.