水楊酸
Salicylic acid is a non-steroidal anti-inflammatory drug (NSAID) almost identical to aspirin. In fact, aspirin's mechanism of action as an NSAID results from it being metabolized into salicylic acid. It is often incorrectly thought to be a drying agent; however, this is not true. Salicylic acid works as a keratolytic, comedolytic, and bacteriostatic agent, causing the cells of the epidermis to shed more readily, opening clogged pores and neutralizing bacteria within, preventing pores from clogging up again by constricting pore diameter, and allowing room for new cell growth.