Benzoyl peroxide (BP) is one of the most effective and widely available acne treatments in the UK. It is sold over the counter at pharmacies in strengths of 2.5%, 5%, and 10% under brand names such as Acnecide and PanOxyl.
How Does It Work?
Benzoyl peroxide has three main actions against acne:
- Antibacterial: It releases oxygen into the pore, killing C. acnes bacteria. Unlike antibiotics, bacteria cannot develop resistance to benzoyl peroxide.
- Keratolytic: It helps shed dead skin cells, preventing pore blockages.
- Mild anti-inflammatory: It reduces redness and swelling around spots.
Choosing the Right Strength
Research shows that 2.5% benzoyl peroxide is nearly as effective as 10% but causes significantly less irritation. Dermatologists often recommend starting at the lowest strength and increasing only if needed.
Application Tips
- Apply a thin layer to the entire acne-prone area, not just individual spots.
- Start with application every other night for the first two weeks, then move to nightly use.
- Always follow with a fragrance-free moisturiser.
- Be aware that BP bleaches fabrics — use white pillowcases and old towels.
Side Effects
Dryness, peeling, and mild stinging are common in the first few weeks. These typically settle as your skin acclimatises. If irritation is severe, reduce frequency to every second or third night.
A small number of people are allergic to benzoyl peroxide. If you develop significant swelling, itching, or blistering, stop use immediately and seek medical advice.
Using BP With Other Treatments
Benzoyl peroxide pairs well with topical retinoids like adapalene. Apply the retinoid in the evening and BP in the morning, or alternate nights. It is also a key ingredient in combination products such as Duac (BP + clindamycin) and Epiduo (BP + adapalene).
For many people with mild-to-moderate acne, benzoyl peroxide alone — used consistently — can deliver excellent results without needing a prescription.