What it does
Lactic acid is a bigger molecule than glycolic acid, so it works more slowly and more superficially — which is precisely why it suits people whose skin does not enjoy being pushed. It also has humectant properties, so it is less dehydrating than its reputation as an acid suggests.
It is a good starting exfoliant: low strength, once or twice a week, in the evening, followed by moisturiser. If nothing objects after a month, you can increase frequency before you increase strength.
The same sun-sensitivity rule applies as with any AHA — daily sunscreen, no exceptions.
In a routine
Layers well with
- Hyaluronic acid
- Ceramides
- Glycerin
Do not layer with
- Retinol
- Glycolic acid
Same routine is fine for some pairs — same step is the problem. Split them morning and evening when in doubt.