Glycolic Acid

What it is

Glycolic acid is an alpha hydroxy acid, or AHA, used in exfoliating skincare. It is water-soluble and has a relatively small molecular size compared with other common AHAs. It appears in cleansers, toners, serums and creams, at different strengths and with different intended use. Those formula differences matter more than trying to judge a product from the ingredient name alone.

Unlike salicylic acid, glycolic acid is not oil-soluble. It is generally used to exfoliate the skin’s surface, rather than being selected specifically for oilier-looking pores. The word acid can sound dramatic, but the practical question is how often the finished product is meant to be used and how your skin responds.

What it does

• Exfoliates the surface. Glycolic acid helps loosen dead skin cells, which can make rough texture look smoother.
• Brightens the look of dull skin. Regular use may help skin look more even and radiant over time.
• Softens the look of some uneven tone. It is used in routines for the appearance of discoloration, though results vary.
• Can irritate. Stinging, dryness, redness or peeling are possible, especially with frequent use or several exfoliants in one routine.

Who it suits

Glycolic acid may suit people looking for a surface exfoliant to address the look of dullness or rough texture. It is not a must-have, and people with sensitive or dry skin may find it too strong, particularly in a leave-on formula. If you are new to acids, choose one product, follow its label and begin less often than daily. Persistent skin changes or irritation warrant advice from a dermatologist.

What to pair it with, and what not to

Use glycolic acid alongside a gentle cleanser and moisturizer, rather than building a routine around several exfoliants. Hyaluronic acid can be a hydrating companion, and sunscreen is important: use it as directed during the day while using exfoliating acids.

Avoid over-layering glycolic acid with lactic acid, mandelic acid or salicylic acid, especially when starting out. Retinoids can also add to irritation when combined with exfoliating acids. Introduce actives one at a time, patch-test new products and pause or reduce use if discomfort continues.

Skin Realist check: A smooth-skin plan should not leave you planning around a peeling face. Start with less than your enthusiasm suggests, and see how your skin votes.