Obagi Professional-C Serum 20% (1 fl oz) Grant your skin the defense it needs to stay healthy and fit with Obagi Professional-C Serum 20%. It's designed to visibly reduce the signs of aging, protect your skin from future damage from free radicals, and support healthy skin function. The smooth serum also boosts collagen, brightens skin tone, and restores needed moisture and hydration to improve the skin's tone and texture. Obagi�s strongest Professional-C Serum provides the strongest brightening effects. Directions: Apply a few drops to your face, neck, and chest in the morning. If you are using the Obagi-C Rx line, you will want to replace it with the C-Clarifying Serum to boost the Vitamin C benefits, but not until after sufficient lightening results have been achieved. INGREDIENTS: Ascorbic Acid, Propylene Glycol, Water, Propylene Carbonate, Fragrance