Formulated by Acne.org founder Dan Kern. * Our formula contains an optimal 2.5% benzoyl peroxide. Studies show that 2.5% works as well as 10% solutions, without the excessive dryness and irritation. * Benzoyl peroxide has been clinically proven to quickly kill over 99.9% of acne bacteria. * Our benzoyl peroxide is pharmaceutical grade and triple milled so it penetrates the skin better than many benzoyl peroxide products. * Generously sized 8 oz. tube.