There are numerous clinical publications supporting the use of traditional a-hydroxy acids (AHAs), including glycolic acid, lactic acid, and citric acid, to counter aging. Studies have demonstrated significant dermal effects, including increased deposition of glycosaminoglycans, improved elastic fiber quality, and collagen gene induction. These dermal effects provide antiaging benefits to skin. Lactobionic acid, a next-generation AHA possessing a polyhydroxy structure (a so-called polyhydroxy acid), has been shown to provide textural and smoothing benefits to skin and to increase skin thickness via digital caliper measurements, thereby providing multiple antiaging benefits. Lactobionic acid is also an antioxidant chelating substance that suppresses matrix metalloproteinase enzymatic activity, helping to protect against further sun damage. Lactobionic acid has also been shown to be gentle to skin without causing the stinging and irritation associated with some AHAs. This study was conducted to assess the efficacy of topical lactobionic acid 8% to reduce the visible signs of aging skin on the face and to determine histologic and dermal thickness changes on the arm during 12 weeks of controlled usage. Results indicate significant improvements in clinically graded parameters, a significant reduction in mild preexisting irritation, and significant increases in skin firmness and thickness. Histologic examples of reduced matrix metalloproteinase-9 activity and increased staining for glycosaminoglycans were observed. When used alone, either as a preventive or an active treatment, lactobionic acid provides beneficial antiaging effects. Owing to its gentleness, it may also be used in combination with cosmetic procedures.