Benzoyl Peroxide 2.5% may be used as an adjunct in acne treatment regimens including antibiotics, retinoic acid products, and sulfur/salicylic acid containing preparations. For the treatment of acne. Goes deep into pores where pimples begin. Has been prescribed by doctors for years. The active ingredient goes to work fast and deep into the pores where pimples begin. Benzoyl peroxide has been prescribed by doctors and dermatologist for years.