Carnosine (dipeptide - a small, two amino acid (β-Ala-His) one) — the one used in cosmetic products is synthetically produced in a lab to copy the natural thing. Carnosine targets the interaction of proteins and sugar molecules which create pro-aging Advanced Glycation End Products or AGEs (associated with skin aging). Inhibition of glycation of proteins of extracellular matrix may help skin texture and appearance. Topically applied carnosine has been shown to prevent AGE formations and reduce levels of AGEs in both epidermis and reticular dermis in human skin explants. A 2017 review paper on topical carnosine writes that it is a "well-documented aqueous antioxidant with wound healing activity."