Mandelic Acid: Why It's A+ For Sensitive Skin, How To Use It & Best Products

How familiar are you with your exfoliating ABCs? Some players definitely receive more fanfare than others (glycolic acid, lactic acid, and salicylic acid are widely known crowd-pleasers), but we suggest another ingredient that deserves a space on your shelf, especially if you have sensitive skin: mandelic acid. 

Mandelic acid is a member of the alpha-hydroxy acid family, which means its main gig is to exfoliate, brighten, and stimulate cell turnover. Like several other AHAs, it's derived from plants—in mandelic's case, bitter almonds—and it hydrates the skin while sloughing off dead cells.

As board-certified dermatologist Mona Gohara, M.D., tells us about the acid family: "They can be simultaneously exfoliating and hydrating, making them very beneficial to many skin types." 

Some AHAs can be more intense than others—glycolic acid, for example, has the smallest molecular weight of the bunch, which means it can penetrate the skin's outer layer quite easily. Mandelic acid, on the other hand, is larger in molecular size (even larger than lactic acid!), which may make it more tolerable for easily irritated skin types.

"AHAs exfoliate skin by breaking the connection between dead skin cells in the top dead skin cell layer, called the stratum corneum," says board-certified dermatologist Cynthia Bailey, M.D., founder of Dr. Bailey Skin Care.

"Exfoliation can improve skin circulation, encourage skin turnover, and improve the absorption of certain skin care products," board-certified dermatologist Raechele Cochran Gathers, M.D., once told mbg.

By promoting cell turnover, you can help push fresh, baby skin cells up to the surface—which can lessen the appearance of dark spots.

"Mandelic acid has a unique affinity for oil compared to other AHAs," says Bailey. "It can penetrate deeper into oily pores and has even been shown to reduce [excess] sebum production and oily shine2."

Due to its exfoliation properties, mandelic acid can help plump the skin and smooth the appearance of fine lines. The act of exfoliation, as we’ve noted, removes the top layer of dead skin cells, revealing younger skin underneath. 

As we noted earlier, mandelic acid has a larger molecular size than other acids. While this may sound like it’d make the acid stronger, it’s actually the opposite. Due to its size, it’s not able to penetrate as deep into the epidermis.

Of course, it depends on your individual skin type and the products you're using—hyperpigmentation, for example, is notoriously difficult to get rid of, as it can take months to completely clear.

If your main goal is to simply resurface the skin and promote cell turnover, you may see quicker results.

"Minor redness or dryness may occur, but the beauty of this ingredient is it tends to be very gentle," says Del Campo. Even though the acid does have a larger molecular weight, it still has the potential to trigger flares, especially if you've exfoliated your skin too much. 

Both mandelic acid and glycolic acid are popular exfoliators used in products. So you might be asking, which one is best for you? 

Well, they’re both alpha hydroxy acids, but mandelic acid is much larger than glycolic acid. (In fact, glycolic acid is about half the size4 of mandelic.) This means glycolic acid is able to penetrate much deeper into the epidermis, making it much stronger—but more irritating.