How to use them
Alternate nights, for example Benzoyl Peroxide on Monday, Wednesday and Friday and PHA 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 PHA first, wait a few minutes, then apply Benzoyl Peroxide.
- 1CleanseGentle cleanser, pat dry
- AMPHA (day 1)then moisturiser and SPF 50
- PMBenzoyl Peroxide (day 2)then moisturiser
What Benzoyl Peroxide does
It kills acne-causing bacteria (C. acnes) by releasing oxygen into the pore. It works fast on inflamed pimples, but it is drying and can bleach towels and pillowcases.
- Typical strength
- 2.5% – 5%
- When
- AM/PM
- Irritation
- Best for
- Oily And Combination skin
Everything that pairs with Benzoyl Peroxide →
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 →
Frequently asked questions
Can I use Benzoyl Peroxide and PHA together?
Yes, but not at the same time. Both fight acne, but together they can seriously dry out skin. Many people use a salicylic or AHA product in one routine and benzoyl peroxide in the other, or alternate days.
Which goes first, Benzoyl Peroxide or PHA?
Apply PHA first, then Benzoyl Peroxide. 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 Benzoyl Peroxide in the morning or at night?
Benzoyl Peroxide: works morning or night. 2.5% works about as well as 10% and irritates less. Use as a short-contact wash or a spot treatment, and keep it away from fabrics.
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.
Is Benzoyl Peroxide with PHA safe during pregnancy?
Neither is a known risk in normal cosmetic amounts, but guidance varies for Benzoyl Peroxide. Check with your doctor.