See it in 3D
Ingredient Atlas · Alpha hydroxy acid

Glycolic acidThe smallest AHA

It loosens the bonds between dull surface cells so they shed, revealing smoother, brighter skin. It also makes skin more sensitive to the sun.

At-home strength10% or less
pH3.5 or higher
WhenNight, 1–3 times a week
Sun careSPF during and 1 week after
Drag to spin · Hydrogens hidden
C2H4O376.05 g/mol · PubChem CID 757
CarbonOxygen
?

Make this page about your skin

Set up your skin profile in the Skin Lab and this page will show what glycolic acid means for you.

Build my skin

What it does

How strong the evidence is for each job. More dots means more and better studies.

Smoother, brighter surface

It exfoliates dull surface cells. Dermatologists use stronger glycolic peels for photoaging, acne and uneven tone.

Moderate

Helps dark marks

Glycolic peels are used for melasma and marks after acne. At home, gentle exfoliation helps pigmented cells shed.

Limited

Raises sun sensitivity

After 4 weeks of AHA cream, sensitivity to UV redness rose 18% and UV cell damage about doubled. It reversed within a week of stopping.

FDA data

Where it works in your skin

Simplified, but true to how the research explains it.

Surface filmBarrierLiving epidermisDermis

Step by step

  1. Its tiny molecule slips between surface cells.
  2. It loosens the bonds holding dull cells together.
  3. They shed, so skin looks smoother, and is more exposed to UV.
Try it in the 3D Skin Lab

Which strength?

Higher strengths are for in-clinic peels done by a professional. Start with fewer nights a week, not a higher percentage.

What to pair it with

Go easy

Retinol on the same night

Together they often irritate. Alternate nights.

Vitamin C at the same time

Both are low-pH. Keep vitamin C for mornings.

A damaged barrier

Pause acids until your skin feels comfortable again.

How to use it

  1. Night, a few times a week

    Start once or twice a week.

  2. Clean, dry skin

    Apply a thin layer and avoid the eye area.

  3. Moisturize

    Follow with a soothing moisturizer.

  4. SPF every morning

    Keep it up for a week after you stop, too.

Questions people ask

How often should I use glycolic acid?

Start once or twice a week at night. If your skin stays comfortable, you can build up to every other night.

Why does it sting?

It’s an acid with a low pH. A mild tingle is common, but burning or redness that lasts means you should stop and let your skin recover.

Can I use it with retinol?

Not on the same night for most people. Alternate them so your skin isn’t overwhelmed.

Do I really need sunscreen with it?

Yes. FDA data showed AHAs roughly doubled UV damage to skin cells after four weeks, and the effect lasts about a week after stopping.

Product picks are coming soon. We'll list glycolic acid products by skin type and price, with clear notes on any affiliate links.

Explore the Skin Lab

Sources

  1. US Food and Drug Administration. Alpha hydroxy acids. FDA
  2. Sharad J. Glycolic acid peel therapy: a current review. Clin Cosmet Investig Dermatol. 2013;6:281–288. Article
Draft: pending review by a dermatologist or cosmetic chemistLast updated 6 Nov 2026