Beta-hydroxy acid (salicylic acid) 

Beta-hydroxy acid is a organic acid also known as salicylic acid that removes dead skin cells. It exfoliates the skin causing the cells of the epidermis (upper layer of skin) to shed more easily, making room for new cell growth. This can help increase skin thickness, collagen production, reduce wrinkles & roughness plus improve hyperpigmentation (texture and color of sun-damaged skin). It can also penetrate deep through the epidermis to exfoliate the dead skin cells and excess oil built up in the pores to treat blackheads, whiteheads and acne. Studies have shown that salicylic acid is less irritating than skin care products containing alpha-hydroxy acids, while providing similar improvement in skin texture. As with any products that exfoliate the skin, it is very important to wear a daily sunscreen.