Lactic acid (AHA): what it does and how to use it
Lactic acid is a gentler AHA that exfoliates and hydrates at the same time. Like all AHAs, it increases sun sensitivity.
What it does
- Smooths rough, dull skin by loosening dead cells.
- Also acts as a humectant, so it feels less drying than glycolic acid.
- At low levels in moisturizers it mainly hydrates.
Strength and rules
- Same US safety finding as glycolic acid: 10% or less, final pH 3.5 or higher, with sun protection or a sun warning.
How to use it
- A good first acid for dry or sensitive skin.
- Use sunscreen daily and for a week after stopping.
Who should be careful
- Skip it on broken or sunburned skin.
Sources
General information, not medical advice. If you have a skin condition or are pregnant, ask your doctor.