A variety of acne products can be purchased on drug store shelves without a prescription. Most of these contain chemicals such as benzoyl peroxide that is helpful with mild cases of acne, especially for people with blackheads and whiteheads. Other forms of over-the-counter treatments may contain salicylic acid, an exfoliating chemical that helps to remove dead skin cells that build up in acne-prone pores. Usually, it takes up to 2 or 3 months for these treatments to have their optimal effects. While these and other similar products are helpful in treating mild or moderate acne, they are often not enough to achieve the best results. The addition of prescription treatments can be very important for an optimal response.