Acne vulgaris affects over 80% of teenagers, and persists beyond the age of 25 years in 3% of men and 12% of women. Typical lesions of acne include comedones, inflammatory papules, and pustules. Nodules and cysts occur in more severe acne and can cause scarring and psychological distress.We conducted a systematic review and aimed to answer the following clinical question: What are the effects of topical and oral treatments in people with acne vulgaris? We searched: Medline, Embase, The Cochrane Library and other important databases up to June 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 67 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: topical treatments (adapalene, azelaic acid, benzoyl peroxide, clindamycin, erythromycin (alone or plus zinc), isotretinoin, tetracycline, tretinoin), and oral treatments (doxycycline, isotretinoin, lymecycline, minocycline, oxytetracycline, tetracycline).