Salicylic acid which occurs naturally in nature softens, loosens and sheds dead skin cells on the skin�s surface and interior of the follicle wall. This is called keratolytic activity which improves the look and feel of the skin plus helps unblock clogged pores. Salicylic acid is known as a beta hydroxy acid because of the two molecular chains as opposed to an alpha hydroxy acid (glycolic acid) with one molecular chain. Since the molecular chain is larger it does not penetrate as deeply as an alpha hydroxy acid (glycolic acid) into the skin and considered excellent for surface work on acne and aging. Acne users appreciate the antiseptic and antimicrobial properties which reduce bacteria. Combined with an alpha hydroxy acid like glycolic acid the formula becomes synergistic meaning the formula is stronger with the combination than if used alone.