Used to treat mild, moderate and severe acne, the effectiveness of over-the-counter medications lies in the product’s active ingredient(s). Not all active ingredients work the same way. The active ingredient benzoyl peroxide reduces P. acnes(bacteria); whereas, salicylic acid helps correct abnormal skin shedding. For lesions to clear, the product(s) must be effective against the factor(s) causing the acne. The following describes common active ingredients used in over-the-counter acne medications sold in the United States. Check with your dermatologist or pharmacist before combining acne products.

Alcohol and acetone Found together in some over-the-counter medications used to treat acne, acetone works as a degreasing agent and alcohol has mild antimicrobial properties. When used alone, acetone tends to have no effect.

Benzoyl peroxide The mainstay of over-the-counter acne treatment, benzoyl peroxide works to clear up acne by reducing P. acnes and removing dead cells from the skin to prevent comedones. It was one of the first agents found to be effective in treating mild acne and has been used in acne treatment for decades. The principal side effect is excessive dryness of the skin, so be sure to follow directions and not use more than stated unless otherwise instructed by a physician. Care should also be taken when applying it to avoid the bleaching effect. Benzoyl peroxide has been known to bleach hair, sheets, towels and clothing. For this reason, an old shirt should be worn after applying benzoyl peroxide to acne on the back or chest. Benzoyl peroxide is available over-the-counter as a lotion or gel. Use of benzoyl peroxide should be continued after acne clears to prevent new lesions from forming.
“Herbal,” “organic” and “natural” products Over-the-counter products labeled “herbal,” “organic” or “natural” are marketed as acne treatments but their effectiveness has rarely been tested in clinical trials. The value of such treatments is generally unknown.

Resorcinol A popular ingredient in over-the-counter acne medications, resorcinol controls small acne lesions and is frequently combined with sulfur in over-the-counter products.

Salicylic acid Effective in treating non-inflammatory acne lesions, salicylic acid helps correct the abnormal shedding of skin cells and unclog pores to resolve and prevent lesions. Salicylic acid does not have any effect on sebum production or P. acnes. Like benzoyl peroxide, salicylic acid must be used continuously. Once stopped, pores clog and acne returns. Salicylic acid is found in many over-the-counter acne products, including lotions, creams and pads. It may be irritating to the skin.

Sulfur Sulfur has been used for more than 50 years in combination with other agents, such as alcohol, salicylic acid and resorcinol and is found in many over-the-counter acne medications. While long used to treat acne, it is not known how sulfur works to clear acne. Due to its unpleasant odor, sulfur is not frequently used alone as an acne treatment.