Salicylic Acid is a beta hydroxy acid that exfoliates the skin. This 2% treatment solution helps exfoliate the inside walls of pores to fight the appearance of blemishes and for better visible skin clarity with continued use. Contraindications: This formula should not be used on sensitive, peeling or compromised skin. Please refer to additional sun protection note and other warnings in provided Directions. Note: While exfoliating acids can result in quick visible benefits, we generally suggest indirect forms of skin exfoliation in favour of direct forms such as this formula due to potential inflammation and sensitivity associated with acids. Please refer to NIOD's Non-Acid Acid Precursor for such a reference. Note: This product is not medicine. If you are fighting extensive or persistent acne, please consult a physician. Effective medicine exists to fight acne successfully, including retinoic acid and benzoyl peroxide.