Topical anti-acne (oxidising / antibacterial / keratolytic) Pregnancy: Considered safe — minimal systemic absorption; first-line topical anti-acne in pregnancy.

Benzoyl peroxide

Brand names: Acnecide, PanOxyl, Epiduo (with adapalene), Duac (with clindamycin)

Adult dose

Dose: Apply thin layer to affected areas OD–BD. Start with 2.5% or 5%; escalate to 10% if tolerated. Begin with shorter contact (15 min then wash off) and build up to overnight contact.

Route: Topical

Frequency: Once or twice daily

Bleaches hair, fabric, towels and bedlinen — counsel about white pillowcases/towels. Wash hands after application.

Clinical pearls

Antibacterial against Cutibacterium acnes WITHOUT inducing resistance — must accompany topical or oral antibiotics for acne (NICE NG198) to prevent antibiotic resistance.
Combination products (Duac = BPO + clindamycin; Epiduo = BPO + adapalene) preferred over monotherapy — better efficacy, fewer steps for adherence.
10% strength is no more effective than 5% but more irritating — start lower and escalate.
Effective in folliculitis (especially Pseudomonas hot-tub folliculitis) and as decolonisation adjunct.
Bleaches towels, pillowcases, dark clothing — recommend white linens during treatment.

Contraindications

Hypersensitivity
Avoid contact with eyes, mouth, nostrils, mucous membranes, broken skin

Side effects

Skin irritation: erythema, dryness, scaling, burning
Contact dermatitis (1–3% — true allergy)
Photosensitivity
Bleaching of hair, eyebrows, fabric
Initial worsening / 'purge' in first 1–2 weeks

Interactions

Other irritants (retinoids, salicylic acid): apply at different times
Sunscreens: combine — SPF 30+ daily

Monitoring

Treatment response at 6–12 weeks

Reference: BNF 90; SmPC Acnecide / Duac / Epiduo; NICE NG198 (Acne 2021); BAD Acne Guideline. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways