How to use them
Alternate nights, for example Glycolic Acid on Monday, Wednesday and Friday and Salicylic 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 Salicylic Acid.
- 1CleanseGentle cleanser, pat dry
- AMGlycolic Acid (day 1)then moisturiser and SPF 50
- PMSalicylic 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 Salicylic Acid does
An oil-soluble beta-hydroxy acid that gets inside pores to dissolve the sebum and dead skin behind blackheads, whiteheads and breakouts. It is the go-to for oily, acne-prone skin.
- Typical strength
- 0.5% – 2%
- When
- AM/PM
- Irritation
- Best for
- Oily And Combination skin
Everything that pairs with Salicylic Acid →
Trying to choose one? Read Glycolic Acid vs Salicylic Acid: which is better for your skin.
Frequently asked questions
Can I use Glycolic Acid and Salicylic Acid together?
Yes, but not at the same time. Glycolic Acid and Salicylic 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 Salicylic Acid?
Apply Glycolic Acid first, then Salicylic 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 Salicylic Acid in the morning or at night?
Salicylic Acid: works morning or night. Use as a cleanser daily or a leave-on 2% serum 3–4 times a week. It can dry out skin, so moisturise well.
Is Glycolic Acid with Salicylic Acid safe during pregnancy?
Neither is a known risk in normal cosmetic amounts, but guidance varies for Salicylic Acid. Check with your doctor.