Malic Acid
An apple a day keeps the doctor away…but can it keep the dermatologist away, too? Maybe, when you’re talking about malic acid. An alpha-hydroxy acid derived from, you guessed it, apples, it’s one of the gentler acids out there. Still, just because it has less of a potential for irksome, irritating side effects, doesn’t mean it’s ineffective. Choice for helping to (gently) remove dead, dry skin cells that can leave your complexion dull and lackluster, dermatologists rave about its brightening effects.
Here, dermatologist Sapna Palep, MD, of Spring Street Dermatology in New York City, dermatologist Claire Chang, MD, of Union Square Laser Dermatology in New York City, and dermatologist Gary Goldenberg, MD, assistant clinical professor of dermatology, Icahn School of Medicine at Mount Sinai Hospital in New York City, explain exactly how malic acid works and why it’s worth making it a part of your skincare protocol.
MALIC ACID
TYPE OF INGREDIENT: Exfoliant
MAIN BENEFITS: Exfoliates dead cells on the outermost layer of the skin and promotes cell turnover, leaving skin brighter and more even, and also helping to keep pores unclogged.
WHO SHOULD USE IT: Anyone looking to fade discoloration and/or achieve more radiant skin, as well as those who are acne-prone. It’s also a good choice for those with sensitive skin and for whom other acids may be too irritating.
HOW OFTEN CAN YOU USE IT: Malic acid can be used once or twice daily, depending on what other ingredients it’s combined with.
WORKS WELL WITH: Other alpha-, as well as beta-hydroxy acids at lower doses for synergistic effects, as well as hydrating ingredients such as glycerin and hyaluronic acid. Palep also likes pairing with vitamin C to boost the brightening benefits.
DON’T USE WITH: Be cautious when using it with other acids, or notoriously harsh or irritating ingredients such as retinoids.
What is Malic Acid?
Malic acid is one specific type of alpha-hydroxy acid—AHA, as the cool kids say— a fruit-derived acid that’s naturally found in apples as well as pears. Like other AHAs, it exfoliates the top, superficial layer of the skin, which in turn does everything from smooth out texture to fade discoloration to help unclog pores.1 There are a few key points that set it apart from other acids, however. First and foremost, its size. Malic acid is a larger molecule than other alpha hydroxy acids, such as glycolic or lactic acid.
“This decreases its penetration into the skin, but [makes it] gentler than its other AHA counterparts,” explains Chang. In other words, if other acids have made your skin freak out in the past, malic acid might be a good alternative. It’s a great AHA to seek out if you have sensitive skin and need a gentle option, says Palep. Admittedly, it's also less effective than other acids because it can't penetrate as deep into skin, which is why it's often combined with other AHAs and BHAs in many topical products.
(More on what that means for your skin and how to use those types of products in a moment.)
Malic acid also has the added benefit of acting as a humectant as well, meaning it’s an ingredient that attracts moisture to and traps it in the skin. This added hydration capability, coupled with its larger size and decreased penetration, is what makes malic acid so much gentler than other skincare acids.
Benefits of Malic Acid for Skin
Here’s why malic acid is a worthwhile alpha-hydroxy acid to seek out, especially if you have easily irritated skin.
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Decreases the stickiness of skin cells on the surface of the skin: When dead, dry skin cells get stuck together, they can clog pores, leave your complexion looking lackluster and create an uneven texture. By breaking down some of the ‘glue’ that holds all of these cells (technical term: keratinocytes) together, it exfoliates and brightens the skin. This also speeds up cell turnover, exfoliating build-up and pore-clogging impurities, says Goldenberg. That’s why, along with being a great ingredient for those in search of a generally brighter, more even complexion, it can also be used to treat keratosis pilaris (those annoying bumps or ‘chicken skin’ that pops up on the backs of your arms) as well as acne, he adds.
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Pulls double-duty as a hydrating ingredient: Along with being a great exfoliant, malic acid is also a humectant that helps attract and retain moisture in the skin so that it stays hydrated, notes Chang. This is why the ingredient often pops up in moisturizers.
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Balances the skin’s pH: According to our experts, it keeps the skin at a stable pH. “Maintaining the skin’s pH at its optimal level protects the skin’s acid mantle and overall skin health,” says Chang. While the skin barrier may get all the buzz, the acid mantle is equally important; a superfine film of acid that sits on the surface of the skin, it too is imperative for acting as a barrier against bacteria, viruses, and other nasties that you don't want in your skin.
Side Effects of Malic Acid
While yes, malic acid is notably gentler than other acids, at the end of the day, it’s still an acid. “Any acid can cause inflammation and irritation,” cautions Goldenberg. How it’s formulated—namely what other acids or ingredients it’s combined with—can greatly impact the likelihood of that happening. To that point…