Obagi's Professional-C Serums provide L-Ascorbic Acid, the most bioavailable form of Vitamin C, for optimal skin absorption and results. As we age, our skin doesnt 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.L-Ascorbic Acid 10% - 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.Daily Use of Vitamin C - Proactively fortifies the skin defenses against environmental assaults. Encourages skin to rebound from previous, visible damage for an improved appearance of fine lines, wrinkles and uneven skin tone. Aids in restoring skin's antioxidant strength to help skin appear younger for longer.Usage Instructions Apply 5 to 7 drops of Obagi Professional-C Serum to the face, neck and chest using fingertips , Apply to cleansed skin in the morning before sunscreen or makeup applicationIngredients Propylene glycol, water (aqua), propylene carbonate, L-ascorbic acid, fragrance