Obagi Professional-C Serum 20% provides ultimate antioxidant protection and instant radiance. Suitable for normal to oily skin. Obagi Professional-C Serum 20% is the highest concentrated Vitamin C serum in the Obagi Professional-C range. A strong and powerful formula, Obagi Professional C-Serum 20% helps reduce the appearance of fine lines and wrinkles, evens skin tone and retains skin moisture, giving you a brighter, healthy-looking complexion. With 20% L-ascorbic acid (the most potent form of Vitamin C) to help calm and brighten skin, as well as retain moisture, Obagi Professional-C Serum 20% gives you an instant glow without leaving skin feeling greasy. Best suited to normal to oily skin types. Did you know? Free radicals break down your skin’s collagen and elastin which results in premature skin ageing – the cause of fine lines, wrinkles and dark spots. Vitamin C stimulates new collagen production, reduces fine lines and wrinkles and protects your skin from harmful free radicals and UV exposure.