Obagi Professional-C Serum 15% infuses your skin with L-ascorbic acid, the only form of vitamin C suitable for topical application. Designed to penetrate deep into your skin, this vitamin C serum provides effective antioxidant protection from UV damage as it brightens away hyperpigmentation and encourages the growth of collagen and elastin fibers. | Obagi Medical Professional-C Serum 15%, 1 fl. oz | Dermstore