Benzoyl peroxide has an antibacterial effect. It also has a mild drying effect that allows excess oil and dirt to be washed away. Clindamycin is an antibiotic that prevents bacteria from growing on the skin. Benzoyl peroxide and clindamycin topical (for the skin) is a combination medicine used to treat acne. Benzoyl peroxide and clindamycin topical may also be used for purposes not listed in this medication guide.