Benzoyl Peroxide

What is benzoyl peroxide and what does it do?

Benzoyl peroxide releases oxygen-rich free radicals when it contacts the skin, which kill Cutibacterium acnes, the bacteria involved in inflammatory acne. Because it works by oxidation rather than as an antibiotic, bacteria do not develop resistance to it, which is why guidelines often pair it with topical or oral antibiotics to reduce resistance. It also has a mild comedolytic effect, helping clear blocked pores. It is used as a wash, gel or cream, in strengths commonly from 2.5% to 10%, and lower strengths often irritate less with similar benefit. It can bleach fabric, towels and hair, so application and laundering need care. [1]

What does the evidence show?

Benzoyl peroxide is supported by many randomised controlled trials in mild to moderate acne, and the American Academy of Dermatology guidelines strongly recommend it, alone or combined with retinoids or antibiotics. Its role in limiting antibiotic resistance is well established. Evidence for it as a stand-alone treatment in severe or scarring acne is limited, where combination or systemic treatment is usually needed.

Who should avoid benzoyl peroxide?

People with a known allergy to benzoyl peroxide should avoid it; a small number develop allergic contact dermatitis. It commonly causes dryness, peeling and stinging, so very dry or eczema-prone skin may need lower strengths or short-contact washes. Avoid contact with eyes, lips and broken skin. Check with a doctor before using in pregnancy.

Is benzoyl peroxide available in Singapore?

Acne products containing benzoyl peroxide are generally regulated as medicines in Singapore rather than cosmetics, and lower-strength gels and washes are usually available from pharmacies. Combination products with antibiotics or retinoids need a doctor's prescription. It depends on strength and product, so check with a pharmacist or doctor.

If a dark patch, breakout or irritation is not responding to what you are using, the next step is a diagnosis rather than another product. See the Skin A–Z library for related ingredients.