Glycolic acid treatment increases type I collagen mRNA and hyaluronic acid content of human skin.

Chronic solar irradiation results in both morphologic and functional changes in affected skin. alpha-hydroxy acids, such as glycolic acid, have been shown to improve photodamaged skin. To investigate alterations in collagen gene induction and epidermal and dermal hyaluronic acid production as a result of administered glycolic acid. In this study we compared collagen gene expression from skin biopsy specimens, and epidermal and dermal hyaluronic acid immunohistochemical staining between glycolic acid-treated and vehicle-treated skin. Forearm skin was treated with 20% glycolic acid lotion or a lotion vehicle control twice a day for 3 months. Epidermal and dermal hyaluronic acid and collagen gene expression were all increased in glycolic acid-treated skin as compared to vehicle-treated controls. Our data suggest that epidermal and dermal remodeling of the extracellular matrix results from glycolic acid treatment. Longer treatment intervals may result in collagen deposition as suggested by the measured increase in mRNA.