What Is Mandelic Acid?

Mandelic acid is a gentle alpha hydroxy acid (AHA) created from bitter almonds. This exfoliating AHA can help brighten, smooth, and clear skin when added to skincare products. But unlike other AHAs, mandelic acid typically won’t irritate sensitive skin.1 Here’s what to expect if you add mandelic acid to your skincare routine. 

How Does Mandelic Acid Work?
As an AHA, mandelic acid helps chemically exfoliate dead skin cells off the top layer of skin (the epidermis). On a cellular level, it helps loosen dead skin cells on the surface so new skin cells can take over, leaving fresher, smoother skin. Mandelic acid also helps promote collagen production, which helps plump the skin, improve elasticity, and smooth fine lines.12
Mandelic acid has a large particle size, which causes the skin to absorb it slowly and more consistently. This allows the AHA to stay on the skin’s surface longer as it absorbs, which can cause less irritation for people with sensitive skin.1

Benefits of Mandelic Acid
Because mandelic acid is so gentle, it is often less effective than more potent AHAs. However, mandelic acid is ideal for people with sensitive skin types who can’t tolerate stronger AHAs.1

Improves Uneven Skin Texture
The main benefit of mandelic acid is that it helps exfoliate the skin, giving it a smoother and brighter appearance. As a chemical exfoliator, mandelic acid helps dissolve away dead skin cells that sit on the skin’s surface. When you have excess dead skin, your skin may look dull, rough, or flakey. Applying skincare with mandelic acid can help exfoliate away any unevenness and textured skin.1
AHAs often irritate sensitive skin, but mandelic acid is an exception. Studies show people with sensitive skin and rosacea can use mandelic acid without irritating their skin.1
Reduces Hyperpigmentation 
Mandelic acid’s exfoliating benefits can also help slowly fade dark spots over time by helping to resurface the skin. This can help people with sensitive skin fade dark spots (hyperpigmentation) caused by sun spots, acne scars, and melasma.1 Mandelic acid is also safe for darker skin tones and won’t over-lighten the skin.3
Specifically, mandelic acid peels are typically used to treat melasma if you have sensitive skin or rosacea. Melasma causes brown-pigmented patches on the face or upper lip.1 Hormonal changes during pregnancy often lead to melasma.4 Research also shows peels that combine salicylic and mandelic acid were just as effective as glycolic acid peels. However, the salicylic-mandelic acid peel was better tolerated.3

Treats Acne
Mandelic acid can help treat acne in a few different ways. First, the exfoliating effect of mandelic acid helps remove dead skin and dirt from pores that lead to breakouts.5 Mandelic acid also has antibacterial and anti-inflammatory properties, which may help kill bacteria and reduce acne-related inflammation. Lastly, mandelic acid helps regulate oil production.5
In people with mild to moderate oily skin, mandelic acid can help reduce excess sebum (oil) that can lead to breakouts. An eight-week clinical trial specifically found women who used mandelic acid gel cream twice daily reduced oiliness and shine.6 Studies have also found that 45% mandelic acid peels were more effective at treating inflammatory acne than 30% salicylic acid peels. Mandelic acid peels were as effective as salicylic acid in treating mild to moderate acne but with fewer side effects.5

Improves the Look of Fine Lines
Mandelic acid can gently reduce the appearance of fine lines on aging skin. When you age, your skin naturally loses collagen, which helps give the skin a plump, elastic, and youthful look. Mandelic acid can stimulate collagen production, helping to soften fine lines and wrinkles and plump the skin.12

Older skin also tends to produce less sebum and become dry. A small study found 40% mandelic acid peels helped women between 48-71 years old have more facial oil, which can help moisturize dry skin and improve the look of fine lines.2

Mandelic Acid vs. Other AHAs
Mandelic acid is one of several AHAs that can help exfoliate the skin, unclog pores, reduce fine lines, and brighten dark spots. However, mandelic acid is the mildest and safest AHA that delivers these benefits.1 The most common AHAs in skincare include glycolic and lactic acid. You can also buy skincare with citric, malic, and tartaric acid.7
Like other AHAs, mandelic acid helps remove dead skin cells and boost collagen production. However, mandelic acid has a larger molecule size than glycolic and lactic acid. This helps mandelic acid penetrate the skin more slowly, causing less irritation if you have sensitive skin. However, this size difference also makes mandelic acid less potent.1

Glycolic acid has the smallest particle size, which allows it to penetrate the skin more quickly and deeply.8 This makes glycolic acid more effective at treating oily and acne-prone skin—but also more irritating. Lactic acid offers similar benefits to glycolic acid, but it absorbs slightly slower and can be less irritating. In addition, lactic acid also helps the skin stay hydrated, which glycolic acid and mandelic acid don’t do.9

Mandelic Acid Lactic Acid Glycolic Acid
Derived from Bitter almonds Milk Sugarcane
Ideal skin type Sensitive or dry skin Dry, normal, combination, or oily skin Normal, combination, or oily skin
Molecule size Largest Small Smallest
Main benefits Exfoliates skin and stimulates collagen Exfoliates skin, stimulates collagen, keeps skin moisturized Exfoliates skin and stimulates collagen
Potential Risks
Mandelic acid is considered gentle and doesn’t usually dry out or irritate the skin like more potent AHAs—especially if you use a lower percentage over-the-counter products.1 However, AHAs like mandelic acid can cause sun sensitivity issues, so always apply sunscreen when using mandelic acid.7
Like all AHAs, it is still possible to have a skin reaction to mandelic acid. Potential side effects of AHAs include:7

Dry and flaky skin
Skin peeling
Irritated or red skin
As an extra precaution, you should also avoid using mandelic acid if you’re allergic to almonds.

How to Use Mandelic Acid
Mandelic acid can be an ideal exfoliator for sensitive skin to help reduce breakouts and improve skin texture. If you’re new to mandelic acid, you can find cleansers, serums, and peels with mandelic acid. Serums and peels are the more popular varieties of mandelic acid skincare. These products are typically applied at night after cleansing and followed up with a moisturizer.

Like other types of skincare, mandelic acid becomes more effective the longer you use it.10 You can also visit a dermatologist or esthetician for a higher percentage mandelic acid peels to help treat melasma, acne, and dark spots.3
If you’re opting for at-home mandelic acid products, here’s how to get started:   
Start with lower percentages. You can find over-the-counter mandelic acid serums and peels with upwards of 10% to 15% concentration. Starting with lower AHA percentages, typically under 10%, can help your skin adjust and reduce your risk of side effects.7 Use the product every 2nd or 3rd night for a few weeks to test the tolerance on your skin or test on a small spot for sensitive skin. However, since mandelic acid is less potent, you can typically use higher concentrations safely.1
Apply at night. Use mandelic acid treatments at night to help avoid additional sun sensitivity. 
Use sunscreen. Since mandelic acid can make your skin sensitive to the sun, it’s essential to use sunscreen with a sun protection factor (SPF) of at least 30 every morning. 11
Don’t mix with other exfoliators: Avoid mixing mandelic acid with other AHAs and retinol. This may irritate the skin and lead to dryness. Try alternating days you use products if you want to use other treatments.