Benzoyl peroxide and salicylic acid are two of the most commonly used over-the-counter acne treating ingredients available at the drug store. However, many people don't understand the difference between these two unique acne-fighting medications. Dr. Schweiger explains that, "Benzoyl peroxide and salicylic acid are two of the most effective OTC medications for acne; for this reason, it is important to understand how and why each ingredient treats acne, in order to choose the most effective OTC option for your acne." Benzoyl peroxide works by killing the acne-causing p. acnes bacteria on the skin. It comes in many formulations, including spot treatment creams and gels, and medicated cleansing washes. Salicylic acid works by cleaning out the plugged follicles of the skin, therefore preventing the formation of the precursor to acne. The dead skin cells and excess sebum (oil) that build up in the follicles are removed by salicylic acid. Salicylic acid is also available in a variety of formulations, including spot treatment creams, medicated cleansing washes, and pads. Finding the best OTC treatment for your acne often requires some trial and error, which is why we recommend visiting a dermatologist at the first sign of acne. While you are searching for an effective OTC treatment, your acne may be worsening and could lead to permanent scarring. A dermatologist will be able to get you on an appropriate acne-fighting regimen to eliminate acne quickly, before it leads to permanent marks on the skin. Click here to read more about OTC treatments for acne.