What is benzoyl peroxide?

By Dr Magnus Lynch
MA(Cantab) DPhil(Oxon) MRCS FRCP
Consultant Dermatologist & Dermatological Surgeon

Benzoyl peroxide is a topical antiseptic that reduces the quantity of bacteria in the skin. Naturally occurring skin bacteria including P.acnes contribute to the formation of acne lesions. Benzoyl peroxide also helps to reduce blockage of hair follicles that leads to whiteheads and blackheads.

5% benzoyl peroxide is available in gel and face-wash formulations without prescription and is present at lower concentrations as an ‘active’ ingredient in a number of over the counter products such as cleansers. It is additionally included with other prescription-only topical treatments such as retinoids (e.g. epiduo) or antibiotics (e.g. duac). These are known as combination treatments.

Benzoyl peroxide can be an effective treatment for mild acne, however it takes several weeks until you start seeing the effects. On its own It is not a suitable treatment for moderate or severe acne.

Benzoyl peroxide is a safe treatment, that is usually well tolerated, however it can irritate the skin - particularly if used in large quantities. It can also make your skin more sensitive to sunlight and can bleach clothes and hair.

Related Articles

• What over the counter acne treatment should I use?
• What topical treatments are available for acne?
• What are combination acne treatments?

About Dr Magnus Lynch

I am a London-based Consultant Dermatologist and Dermatological Surgeon. My NHS practice is at Guy's Hospital and is focused on Mohs micrographic surgery and the treatment of complex skin cancers. My private practice additionally focuses on laser treatments, regenerative dermatology, rosacea, acne, pigmentation and scarring. I have particular expertise in the diagnosis and treatment of skin cancer, including minimally-invasive techniques, Mohs micrographic surgery, and facial reconstructive surgery. I studied at the Universities of Cambridge and Oxford, and completed my dermatology training and Mohs fellowship at the prestigious St John’s Institute of Dermatology. I graduated from medical school in 2003 and have worked exclusively in Dermatology since 2012.

I lead a research team at King’s College London investigating the molecular biology of skin cancer and skin cancer diagnostics, and I constantly aim to translate the latest findings into better patient care. You can learn more about my Research.

In recent years I have been involved in Media Appearances, including the Channel 5 series 'Skin A&E', where I perform skin surgeries and treat various skin conditions. Filming for the next series has recently completed and the series will be released later in 2025.

How I can help

I consult with private patients at several well-appointed and conveniently located sites across central London:

• London Bridge Hospital: Conveniently situated within The Shard, next to London Bridge station.
• Skin55 Ltd: Located at 55 Harley Street, this beautiful Edwardian building houses one of the largest private dermatology facilities in the UK with a comprehensive laser suite.
• OneWelbeck: Located close to Bond Street underground station. Mohs surgery, lasers, and other skin surgeries are performed in the state-of-the-art surgical suite here.

A new consultation is £250, a follow up consultation is £220. For more information on fees, please visit Prices.