This is where it gets scientific. Salicylic acid is a beta-hydroxy acid (BHA for short). This matters because it’s what makes it easier to penetrate deeper into the skin to clear out pores. It also is why once it penetrates it can dissolve excess oil, with the acid component. It also breaks apart the skin’s ‘glue’ so loosens dead skin cells and unclogs pores. Salicylic acid works also to reduce sebum secretion, so has a longer impact on excess oil production.
It’s also got anti-inflammatory properties, which make it great for soothing breakout skin.