Obagi Professional-C Vitamin C 10% Serum provides L-Ascorbic Acid, the most bioavailable form of Vitamin C, for optimal skin absorption and results. As we age, our skin doesn't snap back like the way it did in our younger years, resulting in more signs of skin aging, such as the appearance of fine lines and wrinkles. L-Ascorbic Acid is the active form of Vitamin C and is proven to help reduce the look of fine lines and wrinkles. Known as the most powerful form of Vitamin C, L-Ascorbic Acid helps neutralize free radicals, minimize the look of fine lines and wrinkles, and brighten skin tone. This powerful daily antioxidant serum made with 10% L-Ascorbic Acid is effective in defending the appearance of fine lines, wrinkles and photoaging of the skin, while also working to neutralize free radicals and environmental stressors.