Carnosine is a kind of natural antioxidant, which can effectively remove ROS and α - β unsaturated aldehydes generated by fatty acid peroxidation of cell membrane during cell exposure to harmful substances such as ultraviolet rays and metal ions, so as to protect skin and delay skin aging. As shown in the control experiment below, carnosine has excellent antioxidant effect. Efficacy and application of carnosine can effectively remove the active carbonyl species (RCS). RCS leads to the decrease and loss of protein and cell function, and accelerates the aging process. Carnosine is a natural antioxidant, scavenging ROS (reactive oxygen species). Prevent collagen from cross-linking.