Discover Obagi's bestselling Professional C® Serum 20%, formulated with 20% L-Ascorbic Acid and Sodium Hyaluronate. Fast-absorbing serum helps to brighten and even skin tone, reduce the appearance of dark spots, strengthen antioxidant defenses, and improve the appearance of fine lines and wrinkles. For a supercharged, hydrated glow and more youthful-looking skin. Ideal for normal to oily skin types.