Dull, congested, do-nothing skin types are always looking for a quick refresh, and one of the most reliable ingredients to do so is mandelic acid. This nonirritating member of the alpha hydroxy acid (AHA) family is the go-to for efficacy sans irritation. If your skin can’t tolerate most acids or is sensitive or acne-prone, consider gentle mandelic acid.

What is mandelic acid?

Mandelic acid comes from bitter almonds. Cosmetic chemist Laura Lam-Phaure says the acid’s large molecular size (compared to other AHAs like glycolic and lactic acids) allows for gentle application and slower penetration with minimal adverse reactions like drying and flaking. When it comes to OTC skin-care products, a concentration of 2 to 10 percent, like that of The Ordinary Mandelic Acid 10% ($7) and By Wishtrend Mandelic Acid 5% Skin Prep Water ($22) is enough to be effective. Anything higher than that may lead to peeling.

What does mandelic acid do for the skin?

Mandelic acid offers several skin benefits, like a visible reduction in skin redness and minimized photo-aging, wrinkles and hyperpigmentation. “It also improves skin color, texture, and pore size,” adds New York dermatologist Julie Russak, MD.

The acid is well known for increasing cell turnover, which helps lift away dead skin cells for brighter, younger, healthier-looking skin. “Like other AHAs, mandelic acid works as an exfoliator to loosen the connection between superficial skin cells, so they shed more effectively for skin that glows and is more evenly toned,” says Campbell, CA dermatologist Amelia K. Hausauer, MD. “It also helps strengthen collagen—an added boost for better skin tone.”

Dr. Hausauer reveals that mandelic acid is gentler than other acids, like glycolic. “This makes it ideal for those with sensitive skin, dark skin types who are at risk of burns with peels, and acne-prone patients with clogged pores.” In addition, mandelic acid can help lighten lingering acne spots and dark sunspots. “Because it exfoliates, mandelic acid can make you more sun-sensitive, so sunscreen is crucial,” she adds.

Does mandelic acid help with acne?

Dr. Hausauer says that mandelic acid is unique because it is both water and fat/lipid-soluble, “so it can reach deep into the pore where the skin produces sebum. Most AHAs are water-soluble, making them less effective at treating acne. Beta-hydroxy acids like salicylic acid are typically lipid-soluble and having both properties allows the acid to have many different uses,” she explains. “It’s perfect for those with acne-prone skin that is also dry or sensitive because it clears without dehydrating the skin.” 

A study in the Journal of Cosmetic Dermatology found that 45% mandelic acid chemical peels are as effective as 30% salicylic acid peels in those with mild to moderate acne. In addition, mandelic acid proved to be a better treatment for inflammatory lesions with fewer side effects.

Does mandelic acid improve skin tone and uneven texture?

Lam-Phaure calls mandelic acid a gentle acid that works on multiple skin tones and types. “Darker skin tones greatly benefit from its gentleness, which lowers the risk of magnifying hyperpigmentation that other acids can cause. Plus, it acts as a chemical exfoliant to help lighten and brighten the skin, in turn reducing hyperpigmentation.” 

How to use mandelic acid:

Mandelic acid is available as in-office treatments (chemical peels) and at-home products. Even though mandelic acid is mild, don’t overuse it (limit it once or twice per week) to prevent peeling, sensitivity, and irritations. To avoid dryness, couple the acid with hyaluronic acid or another hydrating agent to reinstate moisture.

Mandelic acid is popular in professional-grade chemical peels. Studio City, CA, dermatologist Gene Rubinstein, MD, who often recommends these peels to those with sensitive skin who are not candidates for more invasive procedures. “Mandelic acid peels are my brightening treatment of choice for patients who are on camera and can’t afford to take any downtime but want glowing skin.” Dr. Russak concurs and counts Glytone Mandelic Acid 40% Peel as her favorite option.

For the most part, mandelic acid works well with other ingredients. Though side effects are somewhat atypical, steer clear of mixing mandelic acid with other acids, retinol, and retinoids. “This can cause an over sensitization to the skin, which may cause it to peel, flake, burn, or sting,” advises Lam-Phaure. And never apply mandelic acid to sunburned skin.

How long does it take for mandelic acid to work?

Like most supercharged skin-care products, the results of mandelic acid aren’t immediate, but you can expect to see an improvement in your skin after about the first week or so and full results in six to 12 weeks of consistent use.