Obagi’s bestselling Professional C® Serum 20%, formulated with 20% L-Ascorbic Acid and Sodium Hyaluronate, is a fast-absorbing serum that works to brighten and even skin tone, reduce the appearance of dark spots, encourage the growth of collagen and elastin fibers, and improve the appearance of fine lines and wrinkles. This concentrated formula infuses the skin with a generous 20% concentration of Vitamin C to rejuvenate and brighten the skin while providing effective protection against environmental stressors. Hyaluronic Acid retains long-lasting moisture to prevent dryness, leaving the skin feeling more even and supple with every use.