The Science of Chemical Peels

A chemical peel is a treatment used to improve skin texture and tone. An acid is applied to skin to lower the pH, which loosens the connections between dead skin cells, inducing exfoliation and stimulating new cell growth. This process causes superficial layers of dead skin to peel off, revealing a smoother and more radiant complexion. Chemical peels can also thicken the epidermis, increase dermal volume and stimulate collagen.

Chemical peels have been used dating back to Ancient Egypt. Cleopatra used sour milk to improve the appearance of her skin, according to some sources. Lactic acid (an alpha hydroxy acid) is the active ingredient in sour milk.


Chemical peels are classified as light (superficial), medium, or deep, depending on the depth of penetration of the ingredients used. Light peels exfoliate to various levels of the epidermis. Medium-depth peels treat through the papillary dermis and deep peels to the mid-reticular dermis. Deeper peels require more downtime and increase the chance of side effects, which include photosensitivity, pigment changes and scarring.