Lactic Acid
A gentle AHA that exfoliates while hydrating — the perfect entry-level acid for sensitive skin seeking glow without irritation.
What Is Lactic Acid?
Lactic acid is an alpha-hydroxy acid (AHA) naturally produced by the fermentation of milk (which is why Cleopatra's legendary milk baths actually had a scientific basis). It has a larger molecular size than glycolic acid, meaning it penetrates the skin more slowly and gently — making it the AHA of choice for sensitive skin types. Unlike other AHAs, lactic acid is also a natural humectant, drawing moisture to the skin as it exfoliates. This dual action — gentle exfoliation plus hydration — makes it unique among chemical exfoliants. Lactic acid works by loosening the bonds between dead skin cells, promoting shedding and cell turnover, while simultaneously increasing the skin's natural moisturizing factor (NMF).
Key Benefits
- Gently exfoliates without the harshness of glycolic acid
- Hydrates the skin while exfoliating (unique among AHAs)
- Brightens dull complexion and evens skin tone
- Fades mild hyperpigmentation and post-inflammatory marks
- Improves skin texture and smoothness with regular use
- Suitable for sensitive and dry skin types
How to Use Lactic Acid
Apply a 5% lactic acid serum 2–3 evenings per week, increasing to every other night as your skin adapts. For more experienced users, 10% formulations provide stronger exfoliation. Always apply to clean, dry skin after cleansing, and follow with a hydrating serum and moisturizer. Lactic acid's larger molecule size means less irritation risk, but you should still wear SPF daily. If you're new to chemical exfoliation, lactic acid is the best starting point before graduating to glycolic acid.
Pairs Well With
Pairs beautifully with hyaluronic acid (extra hydration), ceramides (barrier support), and squalane (moisture seal). Can be alternated with a mild BHA on different nights.
Avoid Combining With
Avoid combining with glycolic acid, retinol, or vitamin C in the same routine. Using multiple exfoliants simultaneously leads to barrier damage. Keep lactic acid nights separate from retinol nights.