This revolutionary anti-ageing serum from Obagi® contains a 15% prescription strength concentration of stabilised L-ascorbic acid, the only form of vitamin C that can be effectively absorbed by the body. This revitalising compound penetrates down into the deeper layers of your skin, neutralising free radicals produced from over exposure to the sun and the natural processes of ageing. The clever mechanism of action prevents further damage to the skin and slows down the ageing process. Furthermore, L-ascorbic acid is essential for the cross-linking of new collagen molecules and prevents trans-epidermal water loss. This ensures your skin remains plump and hydrated; leaving your skin looking younger and firmer.