How Should You Use Glycolic Acid?

Glycolic acid is one of the most common active ingredients in skin care products. But what does it do? And how should it be used?

Dermatology resident Angela Wei, MD, pulls back the curtain on glycolic acid and shares its many benefits.

What is glycolic acid?

Glycolic acid comes from sugarcane and is a type of alpha-hydroxy acid (AHA). AHAs are facial acids that are water-soluble (which means they dissolve in water, not oil, and typically work best on the surface of your skin). As the smallest AHA, glycolic acid can actually penetrate skin deeper than other AHAs. It’s used as an exfoliant to help get rid of dead skin cells and unclog pores. The result: Your skin appears brighter, smoother and more radiant.

“Since glycolic acid is so small, it can penetrate the skin more easily than other acids and be a bit more effective,” confirms Dr. Wei. “It helps loosen the connection that holds dead skin cells together on the surface of the skin, leading to fresher, smoother skin underneath.”

Benefits of glycolic acid for the skin

“Glycolic acid has an anti-aging component that helps improve the tone and texture of your skin,” says Dr. Wei.

Glycolic acid is also an exfoliant, which means it:

• Removes dead skin cells and cleans out clogged pores
• Prevents blackheads and breakouts
• Stimulates collagen production
• Improves the appearance of fine lines and wrinkles
• Brightens skin and creates a more even skin tone
• Lightens dark spots that result from mild sun damage or acne
• Helps with the absorption of other products that penetrate your skin, like hyaluronic acid (which helps hydrate your skin)

Who shouldn’t use glycolic acid?

Be cautious about using products that contain glycolic acid if you have:

• Sensitive skin
• Dry skin
• Rosacea
• Eczema
• An active skin infection

“Most people can benefit from glycolic acid,” notes Dr. Wei. “But if you have sensitive skin or skin that’s not healing, it could cause more irritation.”

Glycolic acid is also generally safe in pregnancy when used in low concentrations, but if you’re pregnant or breastfeeding, you should still check with your healthcare provider before using it.

How to use it

Start slow when using products that contain glycolic acid. Test a little bit on one area of your skin and see how your body reacts.

“I would start using glycolic acid once or twice a week and work your way up to using it nightly if you feel your skin is tolerating it,” advises Dr. Wei.

Glycolic acid should be used at night. Like retinols, it increases your sensitivity to the sun.

“As you’ll be at increased risk for sunburn and UV skin damage, you’ll want to apply broad-spectrum sunscreen during the day of SPF 30 or higher and reapply it every two hours throughout the day,” she adds.

And when you’re first starting out, you may want to avoid using glycolic acid with:

• Other exfoliants, like lactic and salicylic acids
• Retinol
• Vitamin C serums

“It helps to reduce the amount of active ingredients you’re using when you’re first trying a new product because you can isolate what’s causing an issue if you’re sensitive to it,” explains Dr. Wei. “You also want to make sure you’re not overdoing it because that can lead to unintended results like irritation, dryness and increased sensitivity.”

For the most part, glycolic acid products are safe to use at home because they usually contain lower concentrations of the facial acid. But in-office chemical peels use higher concentrations. These are usually reserved for people who need more immediate results or have more persistent skin conditions, like hyperpigmentation and melasma.

“You usually see more dramatic differences with in-office procedures, like glycolic acid chemical peels,” shares Dr. Wei. “But with over-the-counter products that use glycolic acid, it may take several months of consistent use before you notice your skin looks brighter or your pigmentation is more even.”