One or a combination of acids is painted on skin like a mask in varying strengths—light (or superficial), medium, or deep.
How they work: The acid solution peels away layers of the skin. Superficial peels increase cell turnover and are used to improve skin texture (and uneven pigmentation); significant wrinkle reduction is unlikely. Medium and deep peels, which encourage collagen production and cell turnover, are more effective for wrinkles, but the deeper the peel is, the longer—and more painful—the recovery. Following a medium or deep peel, skin is red and a surface crust forms. This flakes off after about a week, but skin can remain red for a month.
On the horizon:New, superficial peeling solutions containing citric (from citrus fruits) or malic (from apples) acid are being developed and tested. These formulas could potentially give better results with less irritation than glycolic acid, says Jeffrey Dover, associate professor of dermatology at Yale University School of Medicine.