Differin and Duac are brand name topical acne medications prescribed to people with severe, hard-to-treat acne. Differin, also known as adapalene, is a vitamin-A derivative that prevents pimples from forming by promoting cell turnover in pores and preventing follicles from clogging. Duac is a combination of the antibiotic clindamycin and benzoyl peroxide.
Retinol is an over-the-counter vitamin A-derived topical medication used to treat breakouts. Unlike the prescription-strength Differin, retinol is used to treat mild to moderately severe acne, according to Dermnet NZ, the official website of the New Zealand Dermatological Society. Retinol helps fight acne by promoting new cell production, and prevents the formation of pus-filled pimples.
While there are no over-the-counter versions of antibiotics, when it comes to fighting acne, benzoyl peroxide is one of the closest nonprescription medications you'll get to an antibiotic like clindamycin, the medication found in Duac. Benzoyl peroxide prevents acne from forming by killing the bacteria that cause the production of pimples. One of the benefits of using benzoyl peroxide is that you do not develop a resistance to it like you do with antibiotics. Benzoyl peroxide also reduces swelling and inflammation in papules and pustules, and dries out the sebum that clogs pores, according to the Acne Resource Center. Duac contains 5 percent benzoyl peroxide, an amount that you can buy over the counter.
Salicylic acid is an over-the-counter medication used in some prescription-strength acne medications. Salicylic acid prevents pores from clogging by slowing cells from shedding inside the pore and sloughing off dead skin cells. Salicylic acid is available as a topical cream and gel, as well as formulated with other products, including soap, exfoliator and shampoo, a product that is helpful for people with hairline acne.
Alpha Hydroxy Acids
Alpha hydroxy acids, or AHAs, including lactic and glycolic acid, are over-the-counter acne medications derived from fruits containing sugar, according to MayoClinic.com. They help prevent acne by removing dead skin cells and reducing inflammation. Like vitamin-A derived medications, alpha hydroxy acids promote the growth of new cells. The FDA explains that high concentrations of AHAs are designed to remove the outer layer of skin. AHAs are sold alone, and are also formulated with other products and sold as a "skin peeler," or with soaps, lotions and exfoliators.