Glycolic acid is thought to work through a combination of reducing inflammation, promoting earlier removal of dry skin scales and optimizing moisturization. These three factors promote a more normal looking healthy epidermis. Studies have shown that glycolic acid products cause measurable improvement in the appearance of fine lines and wrinkles. In one study, fine lines were improved one-third after three weeks as measured by computer analysis. Improvement in photodamage with glycolic acid is widely believed to occur and is often discussed in professional publications.
Data documenting improvement in photodamage with glycolic acid use, however, is limited.
Alpha hydroxy acids are among the most effective skin moisturizing agents available. Glycolic acid may also help lighten the skin when used in conjunction with skin bleaching agents such as hydroquinone. It is thought that the glycolic acid works in concert with hydroquinone to lighten the skin more than either agent could if used separately. Glycolic acid products , being acid based, are neutralized at higher pH's and irritating at lower pH's. Manufacturers of these products consider this phenomenon when formulating the products in order to maximize efficacy and minimize irritancy.