How to use them
Alternate nights, for example Glycolic Acid on Monday, Wednesday and Friday and Lactic Acid on Tuesday and Thursday, with a plain moisturiser night in between if your skin feels sensitive. If your skin is resilient and already used to both, you can try layering them: apply Glycolic Acid first, wait a few minutes, then apply Lactic Acid.
- 1CleanseGentle cleanser, pat dry
- AMGlycolic Acid (day 1)then moisturiser and SPF 50
- PMLactic Acid (day 2)then moisturiser
What Glycolic Acid does
The smallest alpha-hydroxy acid, so it penetrates deepest. It dissolves the bonds between dead skin cells for smoother, brighter skin and fades marks, but it is the AHA most likely to sting.
- Typical strength
- 5% – 10%
- When
- PM
- Irritation
- Best for
- Normal, Oily And Combination skin
Everything that pairs with Glycolic Acid →
What Lactic Acid does
A gentler AHA with a larger molecule. It exfoliates while also acting as a humectant, so it suits dry and sensitive skin that cannot tolerate glycolic acid.
- Typical strength
- 5% – 10%
- When
- PM
- Irritation
- Best for
- Dry, Normal And Sensitive skin
Everything that pairs with Lactic Acid →
Trying to choose one? Read Glycolic Acid vs Lactic Acid: which is better for your skin.
Frequently asked questions
Can I use Glycolic Acid and Lactic Acid together?
Yes, but not at the same time. Glycolic Acid and Lactic Acid are both exfoliating acids. Layered together they can over-exfoliate, which shows up as stinging, shiny tight skin and breakouts. Pre-formulated blends are fine. Otherwise, use them on different nights.
Which goes first, Glycolic Acid or Lactic Acid?
Apply Glycolic Acid first, then Lactic Acid. The general rule is thinnest to thickest texture, and lowest pH first. For this pair, though, it is better not to layer them in the same routine at all.
Should I use Glycolic Acid in the morning or at night?
Glycolic Acid: best at night. Use 2–3 nights a week after cleansing. Skip it on nights you use retinoids. Sunscreen is non-negotiable because AHAs raise sun sensitivity.
Should I use Lactic Acid in the morning or at night?
Lactic Acid: best at night. Use 2–3 nights a week. It is good for beginners to exfoliation. Follow with a moisturiser, and wear SPF the next day.