How to use them
Split them up: use Vitamin C in your morning routine (under sunscreen) and PHA at night.
- 1CleanseGentle cleanser, pat dry
- AMVitamin Cthen moisturiser and SPF 50
- PMPHAthen moisturiser
What PHA does
Polyhydroxy acids are the gentlest chemical exfoliants. They work only on the surface, hydrate at the same time, and are usually tolerated by sensitive and rosacea-prone skin.
- Typical strength
- 3% – 10%
- When
- AM/PM
- Irritation
- Best for
- Sensitive, Dry And Normal skin
Everything that pairs with PHA →
What Vitamin C does
A powerful antioxidant that brightens dull skin, fades dark spots and boosts your sunscreen's protection against free radicals. Pure L-ascorbic acid works best at a low pH and oxidises (turns orange) quickly.
- Typical strength
- 10% – 20%
- When
- AM
- Irritation
- Best for
- Normal, Oily, Combination And Dry skin
Everything that pairs with Vitamin C →
Trying to choose one? Read PHA vs Vitamin C: which is better for your skin.
Frequently asked questions
Can I use PHA and Vitamin C together?
Yes, but not at the same time. Pure vitamin C is already acidic. Layering PHA on top lowers the pH further and raises the risk of stinging and irritation. Use vitamin C in the morning and PHA at night.
Which goes first, PHA or Vitamin C?
Apply Vitamin C first, then PHA. 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 PHA in the morning or at night?
PHA: works morning or night. You can use it daily. It is a good first acid, or a way to keep exfoliating on retinoid "rest" nights if your skin tolerates it.
Should I use Vitamin C in the morning or at night?
Vitamin C: best in the morning. Apply in the morning on clean skin before moisturiser and sunscreen. Store it away from light and heat, and throw it out once it turns dark orange.