Lactic Acid

Also known as: AHA, Milk acid

Low ConcernAHAEWG: 4

A gentle AHA exfoliant with added humectant properties — the best entry-point acid for beginners.

How it works

Lactic acid has a larger molecule than glycolic acid, meaning shallower penetration and less irritation. It exfoliates by disrupting corneocyte cohesion while simultaneously functioning as a humectant (it is part of the skin's natural moisturising factor). This dual action makes it uniquely moisturising for an exfoliant.

Concentration note

5% for gentle daily use; 10–12% for intensive treatment.

Best for

Beginners to acidsDry skinSensitive skinDull skinKeratosis pilaris

Avoid if

Active eczemaOpen wounds

Commonly found in

Gentle exfoliant tonersBody lotionsDry skin treatments

✅ Pairs well with

Hyaluronic Acid Ceramide NP Niacinamide Betaine

⚠️ Avoid combining with

Retinol L-Ascorbic Acid

Safety & restrictions

Increases photosensitivity — use SPF. Much gentler than glycolic acid but still causes irritation at high concentrations.

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For informational purposes only. Not medical advice. Consult a dermatologist for personalised guidance.