Okay, so kinda sorta forgot to reapply sunscreen a few times and now you’re dealing with brown spots or splotches. Or maybe you picked at a big zit months ago and still have a mark. Doesn’t matter—put whatever iffy skincare behavior you’re guilty of (or not) in the rearview, because there’s help on the way.

Here to save the day: glycolic acid. Yes, you’ve probably heard about this hero ingredient before. The alpha-hydroxy acid has been around for ages in cleaners, serums, and peels because it really works. In fact, derms recommend it on the reg and even use super-high concentrations for in-office treatments.

“Glycolic is one of the cornerstones of dermatology because it truly can change the landscape of skin by helping improve tone, texture, and fine lines, and it can be used on all skin tones and types—that’s why it’s so popular,” says Jeanine Downie, M.D., founder of Image Dermatology in Monclair, New Jersey.


Dark spots form when abnormally pigmented cells cluster on skin’s surface. Teeny-tiny glycolic acid molecules penetrate deeply and force those cells off your face. “Glycolic dissolves the connections between dead skin cells, so they shed more quickly,” explains Joshua Zeichner, M.D., Director of Cosmetic & Clinical Research in Dermatology at Mount Sinai Hospital in New York City and member of the L'Oréal Paris advisory board. With the pigmented cells gone, the healthier (less- or non-pigmented) cells underneath can claim their rightful place and restore your even-toned complexion.


Glycolic is powerful. The higher the concentration and the longer it sits on skin, the deeper it penetrates and the more layers of cells it removes. That means you’ll see the best results from a serum you leave on, rather than a wash that eventually rinses down the drain.

But be sure to only apply glycolic products at night. “It’s a time of rest and repair for skin, when it naturally undergoes higher levels of turnover, so applying it in the evening lets you take advantage of those processes that are already happening,” Dr. Zeichner says.

With any new product, consider testing a little behind your ear first to see how skin reacts. But this is especially important if you have sensitive skin since glycolic is so potent. If you notice that skin seems a little dry or sensitive, try applying it every other night to start, and put on a lightweight moisturizer first. “It will act as a primer to help minimize potential irritation,” Dr. Zeichner says.

Regardless of whether or not your skin is sensitive, glycolic will make skin extra sensitive to the sun. So always apply SPF in the morning, which you already do anyway, right?


Even though glycolic is a tried-and-true standby, the formulations have improved so much over the years. You can now find products with added hydrators and skin-soothing ingredients. L'Oréal Paris Revitalift Derm Intensives 10% Glycolic Acid contains aloe and hyaluronic acid, which help keep skin calm alongside the highest concentration of the active ingredient recommended by FDA and derms to use at home.

Speaking of concentrations, choose a product that discloses the percentage of glycolic you’re actually getting, says Devika Icecreamwala, M.D., a dermatologist in Berkeley, California. “Between seven and ten percent tend to be the highest concentrations you can find over the counter,” she says. Unfortunately, too many products leave you in the dark, so it can be tricky to know how to adjust up or down as needed.

Once you've found your favorite, make a point of using it regularly to actually see results. These products don't slather on themselves, ya know? Your new baby skin will thank you.

Janes is a freelance writer and editor who specializes in health, beauty and fitness.