All AHAs exfoliate — but not all do it the same way. Lactic acid has a property that distinguishes it from glycolic, the most potent AHA: in addition to exfoliating the stratum corneum, it has its own humectant properties. It's hygroscopic — it attracts water. The result: exfoliation with simultaneous hydration, making it the reference AHA for sensitive, dry and acid-new skin.

The Difference Between Lactic and Glycolic Acid

• Molecular weight: lactic acid has higher molecular weight than glycolic — it penetrates more slowly and affects more superficial layers. Gentler, less irritating.
• Humectant properties: lactic acid is a natural component of skin's natural moisturising factor (NMF). It hydrates while exfoliating. Glycolic doesn't.
• Evidence in hyperpigmentation: lactic acid has specific studies in melasma and post-inflammatory spots, as well as in texture renewal.

How to Introduce It Into Your Routine

Initial frequency: 1x/week for the first 2 weeks. If skin tolerates well, increase to 2x/week. The goal is 2–3x/week for normal/dry skin and 1–2x/week for sensitive skin.

When to apply: always at night. Lactic acid is not a significant photosensitiser, but overnight cell renewal amplifies the effect.

Sequence: cleanse → lactic acid → wait 20–30 minutes → hydrating serum → moisturiser

Incompatibilities That Reduce Efficacy

• Don't combine with retinol/bakuchiol the same night — too much simultaneous renewal irritates
• Don't combine with acidic-pH vitamin C the same night — pH overlap that can irritate
• Don't apply to skin with a compromised barrier — wait until the barrier is stable