Why Dermatologists Want You to Use Glycolic Acid

Glycolic acid is one of those buzzy skincare ingredients you've probably heard about a million times but don't actually know much about. But if you're going to add it to your skincare routine, you probably want a little intel on why it's having a moment.

Glycolic acid is part of the AHA family (that’s Alpha Hydroxy Acid) and is a well-known resurfacing ingredient lauded by derms for its unique ability to target wrinkles and dark spots simultaneously. How’s that for multitasking? Below, top dermatologists break down everything you should know about glycolic acid, including how it works, when to use it, and much more.

What is it?

Glycolic acid is a naturally occurring substance (usually derived from sugar cane) that, when used in skincare products, offers many benefits, from exfoliation to brightening to a reduction in the appearance of fine lines or wrinkles.

Simply put: “It is a chemical exfoliator that gently removes the top layer of skin to help address skin tone, texture, clogging, and wrinkling,” explains Schweiger Dermatology Group dermatologist Michele Farber, MD, FAAD. “It also helps with cell regeneration, removing excess oil and keeping the skin clear.”

What does it do?

Boston-based board-certified dermatopathologist Gretchen Frieling, MD, is fan of glycolic acid because it’s a versatile ingredient designed to reduce hyper-pigmentation and treat wrinkles and acne. “It takes that very top layer of the skin and removes it," she says. "As we age, our skin turnover slows down, so exfoliating the skin with glycolic acid helps reveal newer skin.”

By nature, glycolic acid also makes skin look more luminous. "It exfoliates the outermost dead layer of the skin, which is called the stratum corneum, and improves the reflection of light on the skin,” she explains.

Glycolic acid is an incredibly effective way to exfoliate your skin. “It's better than many physical options like scrubs because they can be abrasive and can cause irritation,” she adds. “When glycolic acid is used at the right percentage and [applied] appropriately, it's a much gentler way to exfoliate the skin.”

When should you use it?

Joshua Zeichner, MD, director of cosmetic and clinical research at Mount Sinai Hospital in New York City, suggests using glycolic acid at night. “The skin undergoes circadian rhythms where specific activities occur in the morning and others at night,” he says. “The evening is a time of rest and repair with enhanced cell turnover. So it makes sense to use an ingredient like glycolic acid in the evening to complement activities that are already naturally occurring.”

Another reason to slather it on at night? “It can make you more sensitive to sunburn,” says Dr. Zeichner. So make sure to apply SPF if you're working the ingredient into your regular routine.

Who should use it?

Because of its wide variety of benefits, it's a great ingredient across a variety of age groups. “Glycolic acid can be used from the teenage years onwards," Dr. Farber says. "At an earlier age, it is best for acne and as needed it is useful for addressing anti-aging and textural concerns." Some glycolic acid-infused products are too harsh for those with sensitive skin. But there are options available for everyone. L’Oréal Paris’ Revitalift Derm Intensives 10% Pure Glycolic Acid Serum contains moisturizing aloe, glycerin, and hyaluronic acid, making it a perfect option for any skin types.

How long should you use it?

According to Dr. Zeichner, improvements in skin texture can usually be seen within a week, with continued improvements over months. “Remember, aging is a marathon, not a sprint, so you have to keep up with the training,” he explains. The good news? “You can continue to use glycolic acid for as long as you want to experience its benefits.”

Dr. Frieling typically tells her clients to anticipate waiting three to six weeks before results kick in. “It takes time to reverse clogged pores and melt the sebum that has already formed under you skin,” she explains. “But regular use of glycolic acid will help keep your pores free of blockages, so pimples don't form again and the skin maintains a clear, bright look.”