Kojic Acid: Does it Really Lighten Dark Spots on the Skin?

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Whether it may be glycolic acid, hyaluronic acid, or anything else, your skincare routine probably already contains at least a couple of different acids. However, if kojic acid isn’t on that list and skin lightening is the aim of your game, then this naturally-derived ingredient is one that you definitely need to know more about.


What is Kojic Acid?

Kojic acid is a natural chemical that is produced by different types of fungi. It’s also a by-product that is created when certain Asian foods are fermented, such as sake, soy sauce, and rice wine.

Commonly used in the food industry as a natural preservative that prevents foods from discoloring, it is also a popular ingredient in skincare and beauty products such as skin lightening creams. Read our guide to the best skin whitening creams that work fast and pick the right one for you.

What Does Kojic Acid Do to Your Skin?


Most of the other skincare acids out there have exfoliating properties, but kojic acid is a little different. When applied topically, it prevents the formation of tyrosine, which is the amino acid that the skin uses to produce melanin.

Melanin is the pigment that gives the skin, eyes, and hair its color, with excess melanin leading to hyperpigmentation and sun spots. As a result, blocking melanin production has a lightening effect, which is why kojic acid may often be recommended as a skin whitening ingredient.

It’s also one of the key ingredients in Meladerm skin whitening cream. Read our review of Meladerm to learn more about this amazing skin whitening cream and find out how to get it.

Skin Benefits of Kojic Acid for Skin

Kojic acid is famed for its lightening effects, but this powerful compound brings a few additional benefits with it too…

Lightens Sun Spots

Whether you call them age spots, dark spots, or anything else, one of the main reasons why kojic acid is so popular is because of the way in which it lightens hyperpigmentation.

Keep in mind that, although often touted as a skin whitening ingredient, kojic acid won’t have an effect on the natural color of your skin tone. Instead, it targets areas of the skin that contain excess melanin, evening out those dark spots to leave you with a clear and balanced appearance.

Helps to Fade Acne Scars

Although primarily caused by sun damage, hyperpigmentation is also an unfortunate side effect of acne, with stubborn scars sometimes refusing to budge.

Many dermatologists recommend that kojic acid be used as a spot treatment on acne scars to lighten them up and finally fade them away.

Can Be Used to Treat Melasma

Melasma is a condition that leads to discoloration. Although hormonal changes are the main cause, other factors play into it too, resulting in noticeable dark patches on the face and body.

While there are many beauty products out there that claim to treat this, we’ve found that these often contain harmful skin whitening ingredients. Fortunately, due to the way in which it lightens discoloration, kojic acid is an effective yet safe alternative.

Three women with different skin tone

Brightens the Skin Tone

Even if you don’t yet have any age spots, your dermatologist may still recommend that you use kojic acid as a way to brighten up your overall complexion.

Sun damage isn’t always easily visible, but UV radiation will still turn your complexion darker and duller. This superstar compound can help to turn this around. As a skin brightener, it can lighten up any uneven parts of your complexion to give you that elusive glow.

Has Powerful Antioxidant Effects

Skin lightening is the main reason why people use this ingredient, but the antioxidant effects of kojic acid aren’t to be ignored either.

The way in which this powerhouse is able to neutralize harmful free radicals in the skin and therefore protect cells from oxidative damage helps to slow down the aging process, keeping fine lines and wrinkles at bay for longer.

Has Antimicrobial and Antifungal Properties

One thing that many don’t expect from kojic acid is its antimicrobial and antifungal qualities. The ingredient is able to inhibit the growth of several different bacterial and fungal strains. If you use kojic acid, your skin will be protected from bacterial and yeast infections.

A Kojic/Amino Acid Hybrid: New Research from Noh et al

The current information on kojic acid is pretty clear when it comes to its benefits. This humble soy sauce derivative holds so much potential, which the experts have recognized and are developing on.

One fascinating study conducted by Noh et al has combined kojic acid with amino acids, resulting in a hybrid of the two. This cutting-edge compound is showing even more promise than kojic acid on its own when it comes to its lightening effects. Keep an eye out for it and check our page for research updates – plenty of product development is in the works around the world and chances are that its use in cosmetic products will be widespread in the near future.

young African American female model has dark healthy skin, white teeth, drinks aromatic espresso, spends leisure time in coffee shop

Is Kojic Acid Safe for Skin?

Many experts have each done their own safety assessment of kojic acid, and all agree that it is safe for the skin, so long as it is used at the right concentration.

Since beauty and cosmetic products, along with their related health information, aren’t regulated in many countries, this is something that you may need to look into yourself, or speak to your dermatologist about. Research suggests a maximum concentration of no more than 4%, although most cosmetic products out there will contain between 1-2%.

If you have sensitive skin, then kojic acid is still safe for you to use, but go with a lower concentration to begin with. Give your skin some time to experience the effects of the ingredient before raising this up.

Kojic Acid Side Effects

Kojic acid may lead to side effects if you use a product concentration that’s too strong for your skin. Contact dermatitis is usually the result of this, meaning redness, irritation, itchiness, and swelling. If this occurs, stop using the product immediately.

You may also find that your lightening products leave your skin more susceptible to sunburns. Make sure that you’re diligent about sun protection, since the damage that UV rays can cause is even more severe on vulnerable skin.

Speak to your doctor or dermatologist if you’re concerned about any negative experiences following the use of kojic acid. They will be able to advise you on the best way to proceed.

How to Add Kojic Acid to Your Skincare Routine

soap and mint leaves on a table

You’ll find a variety of different skincare products out there containing kojic acid, but serums tend to be the most effective. Unlike creams, which mainly work on the surface of the skin, serums penetrate deeper, delivering their ingredients to the cells that can use them the most.

Since kojic acid may cause some irritation at first, you should only use products containing the compound a couple of times a week, to begin with. You can then increase this to daily usage if that’s what the product guidelines recommend.

Although most commonly used on the face, you can use your lightening products on your body too. Their melanin-inhibiting effects will be the same, no matter where you apply them. The only exception is if you have broken skin – hold off until your skin heals, as any acid can be harmful when used on open wounds.

To maximize kojic acid’s benefits, try using it with products that contain glycolic acid. The two together are even more effective at skin lightening than each one individually.

Another popular ingredient in skin lightening products is glutathione. Read our article about glutathione injections and find out what they can do for your skin.


Can kojic acid permanently lighten skin? 

No, kojic acid can’t permanently lighten your skin. However, its lightening effects will continue for as long as you use the products. If you stop using kojic acid, your skin will once again begin to produce melanin, meaning that the general brightness to your complexion will start to dull. Some experience their hyperpigmentation and uneven skin tones returning, while others find that they’re gone for good.

Is kojic acid better than hydroquinone? 

Kojic acid is milder than hydroquinone. While its effects may not be as fast and dramatic, it’s also much less irritating, and can be used on sensitive skin. That being said, many experience fantastic results when using products that contain both of them.

How long does kojic acid take to work?

Skin care night routine

Technically, it starts to work pretty much instantly. However, it will take a few weeks before you notice a difference in your complexion. This will also depend on the concentration of kojic acid in the products that you’re using – the stronger they are, the faster they will work.

Kojic Acid: The Bottom Line

Kojic acid is an ingredient that the best dermatologists highly recommend, with research and published information confirming how effective it is. When it comes down to it, if your main beauty concerns are discoloration and hyperpigmentation, then kojic acid products are definitely worth trying.

Avatar for Alina Jumabhoy
About Alina Jumabhoy

With almost 10 years of experience writing for the skincare industry, Alina brings her unique perspective into all of the in-depth reviews and articles she writes.