Short answer: Glycolic acid is an exfoliating ingredient. It belongs to the alpha hydroxy acid class, or AHA. In skincare it loosens the bonds that hold dead cells together at the skin’s surface so they shed more evenly. People reach for it to improve the look of rough texture, dullness and uneven tone. How strong a product is depends on the concentration, the pH and the rest of the formulation. Whether it suits you depends on the complete formulation and your own skin, and currently irritated skin is the wrong place to start.
Glycolic acid turns up in cleansers, serums and professional peels.
What glycolic acid is
The FDA names glycolic acid and lactic acid as the most common AHA ingredients in cosmetic products. Glycolic acid occurs naturally in sugar cane, lactic acid in sour milk.
Chemically, glycolic acid has the smallest molecule in the AHA class, though size is one factor among several in a finished product. AHAs are water-soluble and work at the skin’s surface, which sets them apart from salicylic acid. AHA vs BHA covers that difference, and What a Lactic Acid Peel Does covers glycolic acid’s closest relative.
What it does on the skin
The top layer of your skin is made of flattened cells that are ready to shed, and they do not always shed evenly. Glycolic acid loosens the bonds between them so they release without being rubbed off. That is chemical exfoliation, as opposed to the physical kind, where a particle or textured tool does the lifting. Physical vs Chemical Exfoliation compares the two.
Any visible change comes from consistent use over time, and the timeline varies with the cause, the product and the person.
Strength belongs to the whole formulation
The FDA’s summary: the extent of exfoliation depends on the type and concentration of the AHA, its pH, and the other ingredients in the product. A percentage alone tells you little.
Format matters too: a rinse-off cleanser and a leave-on serum give the skin different amounts of contact.
You usually cannot judge strength from a label. Many brands keep the concentrations in their proprietary formulations confidential, and a missing percentage is not a sign that anything is wrong. The more useful question is whether the brand tells you about the formulation, its key ingredients, their intended benefits and how to use the product.
Glycolic acid and the sun
In research conducted by the FDA, volunteers’ skin became more sensitive to UV after four weeks of applying an AHA cream, and the effect did not last long after they stopped. FDA guidance recommends that AHA cosmetics carry a sunburn alert advising sunscreen, protective clothing and limited sun exposure while using the product and for a week afterward.
Daily broad-spectrum sunscreen is recommended as part of the routine regardless, and Do You Need Sunscreen Every Day? makes the wider case. If you also use retinol, it is generally used at night; follow the directions for your individual product. Combining exfoliating acids and retinoids can increase irritation for some people, so check the directions for each product you own.
Who tends to reach for it, and who should wait
Glycolic acid tends to appeal to people whose main complaint is texture: skin that feels rough or looks flat in daylight. The formulation and your skin’s response decide the rest.
Start with informed selection. Know what the product is intended to do, whether it suits your skin, how to use it and what it contains. For particularly reactive skin, a small test in an area that makes sense for the product’s intended use can be an additional precaution.
Sensitive is not the same as irritated. Generally sensitive skin may still suit a carefully chosen product. Skin that is cracked, sore, sunburned or currently irritated should not be exfoliated until it settles.
Stop if it objects. Burning, lasting stinging or a rash are reasons to stop, and a reaction that persists belongs with a dermatologist.
Signs you are asking too much of it
More product, or more frequent use than the directions say, does not bring faster results. It tends to bring tightness, stinging from products that never stung, papery flaking and redness that stays between uses.
If that sounds familiar, pause and go back to a gentle cleanse, a moisturizer and daytime sun protection. When you resume, exfoliate less often or less intensely. Simply switching exfoliants without reassessing formulation, strength and frequency may not resolve irritation. Layering several separate exfoliating products invites the same trouble. How Often Should You Exfoliate? goes further.
Professional glycolic peels are a separate class. They are selected and administered by qualified practitioners and differ from home products in formulation, strength, pH and protocol.
Victoria’s approach
Victoria Nash, founder of Esenté Skincare, has been a licensed aesthetician since 2003. She also owns and operates Younger You Clinique and is an experienced skincare educator. She draws on her professional experience at Younger You Clinique when evaluating skincare products and their performance. There is no universal exfoliation schedule. Victoria considers the individual’s age, skin condition, method of exfoliation and how the skin is responding. Skin-cell turnover generally changes with age, so an appropriate interval for one person may be entirely inappropriate for another. The objective is to exfoliate when needed, not simply because a certain number of days has passed.
The Esenté range includes the Liposome Alpha-Beta Serum, an 8% AHA/BHA serum. It is one example, and other Esenté formulations may meet the same need depending on your individual regimen. This article describes glycolic acid as an ingredient, not that serum’s formulation. If you have known sensitivities, check the complete ingredient list on the Esenté website, not only the key ingredients, and follow the directions. Esenté works with boutique manufacturers to develop and select formulations that meet the brand’s ingredient, performance and quality criteria. Unsure whether one belongs in your routine? Ask on the Ask Victoria page.
Frequently asked questions
It loosens the bonds between dead cells at the skin’s surface so they shed more evenly. Skin can then look smoother and less dull. Visible change needs consistent use over time.
Your product’s directions decide it. There is no universal schedule: age, skin condition, the method and your skin’s response all matter. Pause if your skin starts to sting, flake or stay red.
It depends on the complete formulation and your skin. Generally sensitive skin may suit a carefully chosen product used as directed. Currently irritated, cracked or sore skin should not be exfoliated until it settles.
FDA research found increased sensitivity to UV during regular AHA use, and FDA guidance recommends a sunburn alert on AHA cosmetics. Daily broad-spectrum sunscreen is recommended as part of the routine.
Both are ingredients in the AHA class that exfoliate at the surface. Glycolic acid has the smaller molecule, and lactic acid is often considered the gentler of the two.
About the author. Victoria Nash, founder of Esenté Skincare, has been a licensed aesthetician since 2003. She also owns and operates Younger You Clinique and is an experienced skincare educator.
Reviewed by Victoria Nash, licensed aesthetician, founder of Esenté Skincare and owner of Younger You Clinique. This article is educational and is not medical advice. Ask your dermatologist or licensed skincare professional about products appropriate for your own skin and medical history.
