Glycolic Acid

Alpha hydroxy acid that chemically exfoliates and brightens skin.

Also known as: INCI: Glycolic Acid; AHA, hydroxyacetic acid, glycolate.

What it is

Glycolic acid is the smallest alpha hydroxy acid (AHA), derived from sugar cane. Its tiny molecular weight allows it to penetrate the stratum corneum and dissolve the bonds holding dead skin cells together.

What it does

It dissolves intercellular cement between dead skin cells, promoting gentle chemical exfoliation. This reveals fresher skin underneath, improves texture and radiance, reduces fine lines, and can help with hyperpigmentation and acne. Regular use also stimulates collagen remodeling and improves skin barrier function over time.

The evidence

Strong clinical evidence supports its efficacy for exfoliation, texture improvement, and mild anti-aging benefits at 5–15% concentrations. Moderate evidence exists for treating acne and post-inflammatory hyperpigmentation; emerging evidence for collagen stimulation with chronic use.

Best for

Dull, congested, or textured skin; mild acne; post-inflammatory hyperpigmentation; and those seeking gentle chemical exfoliation without physical scrubbing.

Pairs well with

Niacinamide, hyaluronic acid, peptides, retinol (in separate AM/PM routines), and moisturizers to support barrier recovery.

Use cautiously with

Other strong exfoliants (salicylic acid, retinoids, vitamin C at high pH) in the same step; benzoyl peroxide can reduce efficacy. Use cautiously with hydroquinone or other sensitizing actives.

Cautions

Can cause irritation, redness, and photosensitivity, especially at high concentrations or low pH. Avoid during pregnancy without dermatologist approval. Always use SPF 30+ daily. Patch test first; start low and go slow.