What it does
- Gently exfoliates for smoother, brighter skin.
- Hydrates — it is part of the skin's own natural moisturising factor.
- Suits sensitive and drier skin better than stronger AHAs.
How it works
Lactic acid is a larger AHA than glycolic, so it penetrates more slowly and is generally gentler. It loosens surface cells at low pH while also functioning as a humectant, since lactate is a component of the skin's natural moisturising factor. This dual action is why it is popular for sensitive and dehydrated skin.
Use level
- Typical use level
- exfoliating ~5–10%; lower for humectant use
Exfoliating products commonly use around 5–10% at low pH; at lower levels and higher pH it behaves more as a humectant than an exfoliant. Start low to assess tolerance.
Formulation considerations
- Water-soluble; low pH (around 3–4) drives exfoliation.
- At higher pH it acts mainly as a humectant.
- Increases sun sensitivity when used as an exfoliant; advise SPF.
What it pairs with & what to avoid
Pairs well with
- Hydrators and soothing actives
- Niacinamide
Use with care / avoid
- Stacking multiple strong acids/retinoids at once
- Skipping sunscreen when used for exfoliation
Regulatory status
Lactic acid is listed in the EU CosIng database. As an AHA it carries sun-sensitivity labelling considerations; follow current limits for your market.
Common questions
Is lactic acid gentler than glycolic acid?
Generally yes; it is a larger molecule that penetrates more slowly and also hydrates, making it a good choice for sensitive or dry skin.
What percentage of lactic acid should I use?
Around 5–10% for exfoliation at low pH; lower levels behave more as a humectant.
Can lactic acid hydrate as well as exfoliate?
Yes; lactate is part of the skin's natural moisturising factor, so lactic acid has a genuine humectant role alongside exfoliation.