Salicylic acid is a beta hydroxy acid that exfoliates dead skin cells on the skin's surface and decreases oil and sebum, says board-certified dermatologist Joyce Imahiyerobo-Ip, MD, FAAD, owner of

target="_blank" target="_blank">Vibrant Dermatology and SkinBar MD. In addition to being an exfoliant, it also works as a comedolytic and anti-inflammatory ingredient.

"As an oil-soluble ingredient that can absorb into the lipid skin layers more readily, it can penetrate deeper into the skin and the pores," explains Y. Claire Chang, a board-certified dermatologist at Union Square Laser Dermatology. "It exfoliates and brightens skin complexion as well as de-clogs pores to prevent blackheads, whiteheads, and subsequent acne breakouts. Salicylic acid not only helps to prevent and clear active acne, but it can also improve acne blemishing."

And because salicylic acid exfoliates so well, it can also help your topical products better penetrate the skin, which Chang says can be useful in treating conditions like psoriasis. The hardworking ingredient can also be used as a peeling agent for acne vulgaris, melasma, photodamage, sunspots, psoriasis, and warts.