You may know lactic acid best either as the substance your muscles produce after a hard workout, or the phenomenon that makes milk go bad. Neither option would suggest that it does incredible things for your skin. But the lactic acid that can be found in skin care products, like serums, is a type of gentle exfoliant that polishes the surface of your skin to leave it looking even, radiant, and clear. The best lactic acid serums are layered with supporting ingredients, too, like brightening plant extracts, lightweight emollients, or other kinds of AHAs for more intensive exfoliation.
While anyone, anywhere can make use of lactic acid serums, they're an especially good choice for people with sensitive skin. Lactic acid has a larger molecular weight than other AHAs (particularly glycolic acid), so it can’t penetrate your skin as deeply — i.e., less potential for irritation.
With any of the five best lactic acid products featured ahead, you can slough, buff, and smooth your way to a more radiant complexion. Scroll on to find your perfect exfoliating serum match.
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1. The Cult Favorite
The term “cult favorite” gets thrown around a lot, but in the case of Sunday Riley Good Genes, that title is warranted. That’s mainly because users (who swiftly become loyalists) claim to see results — meaning brighter, smoother, bouncier skin — immediately upon application. And that’s because the formula is packed with premium-grade ingredients devoted to making your skin absolutely glow: In addition to 5% lactic acid, there’s brightening licorice, arnica to reduce inflammation, and aloe for hydration, while lemongrass works as a natural astringent to clarify your skin of impurities that contribute to dullness. The consistency lies somewhere between a serum and a moisturizer, so if you have oily skin, you may not even need to follow it up with a moisturizer. Alternatively, you can use it as a mask: Apply to clean skin, leave it on for 15 minutes, rinse it off, and revel in your newly radiant mug.
2. Best Budget Serum
If you can’t spring for an $85 bottle of Good Genes, consider this under-$20 Acure serum instead. From a skin care nerd standpoint, the formula is really exciting. In here, lactic acid gets a boost from glycolic acid, so you’re both polishing the surface of your skin and giving it a deeper cleaning. The addition of glycolic acid makes this an especially good choice if you’re hoping to reduce any unwanted acne scarring, or to tame an active breakout. Calming, soothing, and brightening hemp seed soil and turmeric counterbalance all that exfoliation, too. Consider following it up with the moisturizer from the same (Resurfacing) line.
3. Best Mid-Range Serum
Speaking of things that’ll excite skin-care obsessives: If you’re looking for a serum with all the exfoliants (chemical only, please), this is it. The formula contains four AHAs that work to refine your skin, plus salicylic acid, the BHA made famous for its ability to clear out breakout-causing impurities from your pores (like dead skin and oil). Despite its potency, Amazon reviewers with sensitive skin say they tolerate this serum well, thanks to the addition of skin-soothers like allantoin, green tea leaf extract, and strengthening peptides. If you do have sensitive skin, or if you’re new to exfoliating, stick to applying this only at night. If your skin is a little heartier, you can use it twice daily. To echo one happy reviewer on Amazon, its $37 price tag is “shocking,” considering its absolutely stacked roster of effective ingredients.
4. Best Splurge
Most of the serums on this list can broadly fall under the “clean” skin care umbrella, since they’re made without the most common fillers and additives that are potentially harmful to the human body and/or Earth. But this lactic acid serum from Tata Harper is the only one that can rightfully claim to contain organic ingredients — 67% of them, to be exact, as certified by Ecocert Greenlife according to COSMOS Standard. Among those organic ingredients include aloe, arnica, and calendula to soothe and moisturize your skin, plus sea buckthorn oil, which is rich in healing fatty acids. Meanwhile, lactic acid and other AHAs work to gently retexturize your skin. At $88, this is obviously the priciest option on this list, but the quality and “cleanliness” of the ingredients is unparalleled.
5. Best Body Serum
Lactic acid can work equal wonders on your body as your face, particularly if the wonder you’re trying to work is treating keratosis pilaris. Not only can this 10% lactic acid body serum smooth out rough, bumpy, or unevenly textured skin, but it can help with body breakouts, too. And since it’s a serum, it feels much lighter, less greasy, and more absorbent than your standard body lotion. There are some moisturizing ingredients in here, like shea butter and vitamin E; but if you have very dry skin, you may still need to follow it up with a thicker body lotion. If you do that, wait until the serum absorbs completely to avoid pilling.