Amoxicillin an antibiotic in the Penicillin family. Amoxicillin is a very common antibiotic that is used to treat many different kinds of infection. Amoxicillin is uncommonly used to treat acne. However, many acne patients report Amoxicillin helped improve their acne symptoms. Amoxicillin is available as an oral and topical antibiotic, although oral use is much more common. Amoxicillin shoud not be used by people that are allergic to penicillin or ampicillin due to an increased risk of side effects.