Carnosine

Antioxidant peptide that may help protect skin from damage. Carnosine, a dipeptide of beta-alanine and L-histidine, offers multifaceted skin protection. It acts as a potent antioxidant by neutralizing reactive oxygen species (ROS) and reactive nitrogen species (RNS), and by chelating metal ions like copper and zinc, thereby inhibiting their pro-oxidant activity. A key mechanism is its anti-glycation property; carnosine reacts with carbonyl groups on sugars and proteins, preventing the formation of advanced glycation end-products (AGEs) which contribute to collagen and elastin cross-linking and loss of skin elasticity. It also exhibits anti-inflammatory and membrane-stabilizing effects, supporting cellular integrity.

Carnosine is generally considered safe for cosmetic use due to its natural presence in the human body and extensive research. It is non-irritating and non-sensitizing at typical cosmetic concentrations.

Look for products with 0.1-2% (most formulas use 0.5-1.5%) for clinical efficacy.