What Is Malic Acid And Why Is It A Godsend For Sensitive Skin?

Having sensitive skin does not make creating a skincare routine easy. Have you ever wanted to try the latest, buzziest skincare product on #BeautyTok, only to find it contains ingredients that would wreak absolute havoc on your skin? Or perhaps you bought a serum your friends call their holy grail, but it irritated your skin instead. With sensitive skin, finding ingredients and products that work just fine without leaving your skin feeling uncomfortable or inflamed can be taxing. 

DermNet describes sensitive skin as having reduced tolerance to cosmetics and personal care products, including our good old skin-sloughing favorite, exfoliants. Exfoliation, both physical and chemical, can be tricky to work with when it comes to sensitive skin. Where well-known exfoliating acids like glycolic acid and lactic acid work wonders on other skin types, they can be too harsh for sensitive skin, damaging the skin barrier and causing more harm than good. Oftentimes it seems like people with sensitive skin can't catch a break, or, in this case, exfoliate. Thankfully, there is an option perfect for sensitive skin (per Healthline). If you've been trying — and maybe failing — to find an ingredient that exfoliates without hurting your sensitive skin, we think you're about to fall in love with malic acid.

According to the American Chemical Society (ACS), malic acid is found in unripe fruits like apples and pears. Coined from the Latin word "malum," the ACS explained that malic acid gives apples their tart flavor, hence the nickname "apple acid." So if you've had an apple recently or enjoyed a glass of fruit wine, you have malic acid to thank for that. But this ingredient doesn't just make your apples tasty; it's also excellent for skincare.

As Skin Inc. says, malic acid is an AHA capable of melting off the "glue" between dead skin cells, lifting them off the skin's surface, and clearing debris from pores. Dermatologist Joel Schlessinger, MD, explains that malic acid is also great for your skin's pH, as it helps balance the pH levels on both your skin and in your skincare products, giving you a healthier moisture barrier (per New Beauty).

Clearly malic acid is cool, but you're probably still wondering how this differs from other skincare acids that might be harsh for sensitive skin. Well, here's how.

With their tiny molecules, AHAs can penetrate the skin's layers, encouraging cell turnover while melting the intracellular glue between dead skin cells on the surface and inside pores. And while they all work similarly, all of the different AHAs have different molecular sizes. For example, glycolic acid has the smallest molecular size and can penetrate the deepest into the skin. On the other hand, lactic acid molecules are larger than glycolic acid, but still penetrate pretty deeply. As The Top Shelf Edit explains, the smaller the molecule size, the deeper the AHA penetrates, and the deeper it penetrates, the more it exfoliates. The only problem is that the deeper it penetrates, the more sensitizing it can be. And if there are two things you do not want to deal with together, it's sensitive AND sensitized skin.

Compared to glycolic acid and lactic acid, malic acid's slightly larger molecule size allows it to penetrate the skin much more slowly while still exfoliating it effectively (per Skin City). Essentially, slower absorption into the skin means less sensitization and irritation, making it a sensitive skin favorite for exfoliation.

Malic acid is excellent for sensitive skin due to its molecule size and slower absorption, but it doesn't stop there. As it turns out, this star AHA is also hydrating. According to SkinKraft Laboratories, malic acid is a humectant that attracts water molecules from the air and seals them within the skin. In addition, malic acid's exfoliating action also increases cell turnover and encourages collagen production. 

Increasing your skin's cell turnover rate is essential for making your skin firmer and thicker and reducing the signs of premature aging (per Mooi Skin). By encouraging cell turnover and collagen production, malic acid helps reduce fine lines, wrinkles, and a loss of elasticity in your skin, which is why you'll find malic acid in moisturizing and anti-aging skincare products (per Dermstore). And as a bonus, malic acid also helps clear blemishes and hyperpigmentation and prevents acne (per Skoah). 

Malic acid is an absolute exfoliating godsend for sensitive skin, but is still an alpha hydroxy acid, and dealing with alpha hydroxy acids requires care and caution. Despite its mildness, you could be sensitive or allergic to this acid, and this could cause redness, itching, and burns (per Minimalist). Therefore, you should carry out a patch test before incorporating it into your routine. Conduct the patch test by applying a small amount on the inside of your wrist or the back of your ear and wait at least 24 hours for any signs of irritation.

Alpha hydroxy acids can also make your skin even more sensitive to the sun, malic acid included. So it's crucial to use adequate sun protection during the day (per Skin Inc.). Use a broad-spectrum sunscreen with at least SPF 30 and wear sun-protective clothing.

Sensitive skin girlies, dry skin folks, and even those with combination skin, everyone's welcome to try out malic acid and reap its many benefits (per The Klog). In addition to gently exfoliating your skin, malic acid also increases the efficacy of any other AHAs you might have in your routine. SkinKraft Laboratories explains that using your malic acid-containing product in conjunction with other AHAs can help you get faster results. However, it's best for those with sensitive skin to stick to the most forgiving AHA for their skin, in this case, malic acid. Another thing you need to be wary of while using malic acid, or any exfoliating acids, is your eye contour. The skin around your eyes is thin and, as such, does not need further manipulation by exfoliating. 

Nevertheless, malic acid is worth a try, and you probably can't wait to get into it, so here are our favorite skincare products containing this wonder acid. For treatments, we're fans of Paula's Choice RESIST Advanced Smoothing Treatment 10% AHA, a cocktail of malic acid, lactic acid, glycolic acid, and salicylic acid, a beta-hydroxy acid (BHA). We also recommend the Herbivore Botanicals PRISM 12% AHA + 3% BHA Exfoliating Glow Serum, which boasts a rating of 4 stars on Sephora.