What is Benzac AC 2.5 Gel? Benzac AC Gel is a topical acne treatment that contains Benzoyl Peroxide as its active ingredient. This powerful compound is renowned for its ability to fight acne-causing bacteria and reduce inflammation, making it a staple in many skincare routines. Benzoyl Peroxide works by penetrating the pores and killing the bacteria that lead to acne. It also helps to remove excess oil and dead skin cells, preventing clogged pores and breakouts. This dual-action mechanism is what sets Benzac AC Gel apart as an effective acne treatment.