If you follow beauty accounts on TikTok or Instagram Reels, you might have seen a small bar of orange soap pop up in your feed recently. These orange soaps are the newest beauty trend on the internet and in real life. They are bright in colour and claim to brighten skin.
But this popular soap isn’t as great as everyone says it is. Scientists at the Good Housekeeping Institute Beauty, Health, and Sustainability Lab say that this popular skincare trend isn’t as great as people say it is. The claims that kojic acid soap can make your skin brighter are not true. Our experts say that kojic acid can make your skin look brighter, but we don’t recommend the soap. Before you swear off using it in your skincare routine for good, remember that it can help.
Read on to learn more about this strange ingredient and what you should use instead of kojic acid soap to make dull skin look brighter.
What is the acid called kojic?
First and foremost, what is kojic acid? And why do people want it in their soap? Kojic acid is a skin-lightening chemical that is used in cosmetics. Kojic acid is a natural substance that can also be made in a lab, just like many other skin care ingredients. “Some types of fungi, especially Aspergillus oryzae, naturally make koji acid. However, this organic compound can also be made through biological fermentation of carbohydrates or chemical synthesis,” says Sabina Wizemann, Director of the Beauty Lab at the GH Institute.
What does kojic acid do to make skin brighter?
Studies have shown that kojic acid stops tyrosinase, an enzyme that makes melanin. Kojic acid lowers the amount of melanin made by the body. This has both good and bad effects. Wizemann says that lowering the production of melanin can help even out skin tone, get rid of dark spots, lessen hyperpigmentation, and get rid of melasma. Sadly, there is no rose without a thorn. When using this ingredient, keep in mind that Kojic Acid can make your skin more sensitive to UV rays (more on the risks below).
Kojic acid can not only make skin brighter, but it can also act as an antioxidant and have mild antimicrobial effects. One study found that kojic acid can help stop bacteria from growing and acne from getting worse. Another study found that antioxidants can protect the skin from damage caused by free radicals like dust, smog, and other things.
This is why we don’t think you should buy kojic acid soap.
You might be thinking, “Those benefits sound great!” Why not use a bar of soap every day to rub it on my skin? Don’t worry, I had the same questions. But the Beauty Lab experts all agreed on one thing: kojic acid soaps probably won’t make your skin any brighter. Our scientists say that this popular skincare trend doesn’t really work for the following main reasons:
- You rinse the ingredient off your skin.
- It is not possible to apply soap exactly.
When you lather on soap, it comes off your skin right away, unlike serums and creams. “Because soaps are rinse-off products, the contact time is too short for kojic acid to get deep enough to block the tyrosinase enzyme and stop melanin production,” Wizemann says. This means that none of the kojic acid that is being rubbed into your skin is being absorbed, so it can’t do its job.
Another problem with soaps is that you can’t apply them to just one area of your body or face; they have to be applied all over. This is a problem with kojic acid in particular because it dissolves quickly in water. Wizemann says that this can make it harder to penetrate deeply, and that “it is unstable when exposed to air, light, or higher pH, like in soaps that are usually more alkaline than serums and creams.”
Wizemann says that to get the most out of kojic acid, you need to make sure you are using the right formulation to apply it. She says that “an appropriate environment (like low pH), a combination with other ingredients that help it penetrate, and the right amount of time in contact with the skin are all necessary for it to be helpful.” Kojic acid is one of the many ingredients in soap, but it doesn’t create the right environment or allow for precise application that will get into the skin.
Also, not everyone can use kojic acid.
The Cosmetic Ingredient Review found that kojic acid is safe to use in leave-on cosmetics at levels of up to 1%. However, people with sensitive skin may have some negative effects when they use any product that contains kojic acid. Some people may find that washing their skin with kojic acid soap every day (or even twice a day) is too drying or irritating. “Depending on how strong it is and how long you use it, it may cause redness, tightness, dryness, and irritation, especially in people with sensitive skin or those who are prone to eczema,” Wizemann says.
Kojic acid can make your skin more sensitive to UV rays, even if you don’t have sensitive skin. This can make you more likely to get sunburnt, so you need to be extra careful to put on sunscreen with at least SPF 30 every day on skin that is exposed.
Is there any good reason to use soap with kojic acid in it?
If kojic acid soap doesn’t really work to lighten your skin, then why do so many people on social media say it does? And is it bad for everyone to be doing this skincare trend?
We don’t know why one trend became more popular than another, but remember that some formulas can still be good for your skin. The kojic acid itself isn’t the main ingredient that gives those benefits, though. Wizemann says, “It’s important to remember that all products have more than one ingredient, and the way they work together makes a product work and gives it its benefits.”
Most soaps that are sold as “kojic acid soaps” also have exfoliating agents that help clean. These ingredients can be good for bigger areas, like the back and chest, because they help get rid of dead skin, reduce acne, make skin smoother, and reduce dark spots, according to Wizemann. That means the soap might make your skin look a little brighter over time, but that’s not because of the kojic acid, and it won’t work as well as some serums or creams.
We don’t think you should rush out and buy a bar of kojic acid soap, but if you already have one, it’s not dangerous to use it. Before you buy it, make sure that the Food and Drug Administration (FDA) has approved it. You can check the Drugs@FDA database or the FDA “Orange Book” to see if a product is FDA-approved. The Orange Book lists both brand-name and generic drugs that have been approved by the FDA.
Instead, here’s what we think you should use to brighten your skin:
We don’t really like the trend of using kojic acid soap, but we do think that this ingredient (along with others) can be a great addition to your skincare routine. Wizemann says that “Kojic acid is often found in serums and creams with other brightening actives like niacinamide, vitamin C, and arbutin.” Instead of jumping on the kojic acid soap bandwagon, our Beauty Lab scientists suggest adding it to your skin care routine through serums, peels, and creams.
Our chemists suggest using vitamin C serums and products with niacinamide, a form of vitamin B3 that helps brighten and even out skin tone, if you want more brightening skincare or dark spot corrector products that don’t have kojic acid in them.
Even with these tried-and-true products, you won’t see results right away. Wizemann says that short-term effects like mild brightening may happen in one to two weeks, while more noticeable changes may take four to twelve weeks.
You can learn more by looking at our expert-approved skincare ingredient dictionary, which lists all kinds of ingredients, their benefits, and how to use them.
Why should you believe Good Housekeeping?
The scientists at the Good Housekeeping Institute Beauty Lab test all kinds of skin care products, such as creams, serums, cleansers, and more. Sabina Wizemann, the Beauty Lab Director and cosmetic chemist, has been in charge of testing beauty products at the GH Institute for more than 12 years. Before coming to GH, she worked as a chemist in the pharmaceutical and personal care industries for more than 16 years.
This article was written by Isabella Cavallo, who is the Assistant Commerce Editor. She has written reviews of skincare products and articles about health for many years. She talked to Wizemann and looked up scientific studies to help her write this story.
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