This??medication??is used to treat severe??cystic acne??(also known as nodular??acne) that has not responded to other treatment (such as??benzoyl peroxide??or??clindamycin??applied to the??skin??or??tetracycline??or??minocycline??taken by??mouth). It belongs to a class of drugs known as retinoids. It works by decreasing facial oil (sebum) production. High amounts of sebum can lead to severe acne. If left untreated, severe acne may cause permanent scarring.