Glycolic acid and lactic acid are both alpha-hydroxy acids (AHAs) — chemical exfoliants that dissolve the bonds holding dead skin cells to the surface, allowing them to shed more effectively. But they're not interchangeable. Here's the difference and how to choose the right one for your skin.
Glycolic acid — the powerhouse
Glycolic acid has the smallest molecular size of all AHAs, which allows it to penetrate the skin most deeply and act most quickly. This makes it the most effective AHA for texture refinement, brightening, reducing the appearance of fine lines and treating hyperpigmentation.
The trade-off is that its potency makes it more likely to cause irritation, especially at higher concentrations or with frequent use. It's best suited to normal, oily and thicker skin types that can tolerate active ingredients without reacting.
Our Glycolic Acid Exfoliating Toner delivers glycolic acid in a gentle liquid toner format — effective but formulated to minimise irritation. Use 2 to 3 times per week in the evening.
Lactic acid — the gentle option
Lactic acid has a larger molecular size than glycolic acid, which means it penetrates more slowly and acts more gently on the skin's surface. It's less potent but also significantly less likely to cause irritation — making it the better choice for sensitive, dry and reactive skin types, or anyone new to chemical exfoliants.
Lactic acid also has humectant properties, meaning it can help draw moisture into the skin as it exfoliates. This makes it particularly suitable for dry skin that needs exfoliation without stripping.
Our AHA Peeling Concentrate uses lactic acid alongside hyaluronic acid for a dual exfoliating and hydrating effect — ideal for those who find pure glycolic products too strong.
Which should you choose?
Choose glycolic acid if: you have normal, oily or thicker skin, you're experienced with chemical exfoliants, and you want the strongest brightening and texture-refining effect.
Choose lactic acid if: you have sensitive, dry or reactive skin, you're new to chemical exfoliation, or you've found glycolic acid too irritating in the past.
Can you use both? Yes — but not at the same time. Some people alternate between the two, using glycolic 1-2 times per week and lactic on other days. Build up slowly and listen to your skin.
Rules for all AHA exfoliants
Never use more than once daily. Always use SPF the morning after applying an AHA the night before — exfoliation increases UV sensitivity. Don't use on broken or severely irritated skin. Introduce slowly — once a week for the first two weeks before increasing frequency.