|Alpha hydroxy acids (AHA's) work mainly as an exfoliant. They cause the cells of the epidermis to become "unglued"
allowing the dead skin cells to slough off, making room for regrowth of new skin. AHA's may even stimulate the production of
collagen and elastin, and are reported to improve wrinkling, roughness, and mottled pigmentation of photodamaged skin after months of
daily application. Alpha hydroxy acids found in skin-care products work best in a concentration of 5% to 8% and at a pH of 3 to 4.
Beta hydroxy acid, salicylic acid, is a topical exfoliant that can reverse some of the effects of photoaging such
as fine wrinkles and discolored skin. Currently, salicylic acid is the only beta hydroxy acid used as an exfoliant.