OBAGI PROFESSIONAL-C SERUM 20% OVERVIEW Professional-C Serum 20% is our highest concentrated serum, packed with antioxidants to help minimize the appearance of fine lines and wrinkles while leaving skin feeling silky soft. This high-performance serum is formulated with 20% L-ascorbic acid (Vitamin C), and is best suited for normal to oily skin. Key Benefits: 20% L-ascorbic acid (Vitamin C) encourages skin to rebound from previous visible damage Improve overall complexion by reducing the appearance of fine lines and wrinkles Formulates to immediately absorb and remain in the skin Highest concentrated serum with antioxidant L-ascorbic Acid, best suited for Normal/All Skin Types to oily skin. Uniquely formulated to help reduce the appearance of skin aging and leave skin feeling silky soft. Daily use helps to fortify skin and safeguard your youthful appearance. Formulated with pure L-ascorbic acid to optimize efficacy, permeability, and stability. Obagi Professional-C Serum 20% is the highest concentrated serum with antioxidant L-ascorbic Acid, best suited for Normal/All Skin Types to oily skin. KEY INGREDIENTS L-ASCORBIC ACID 20% - Known as the purest form of Vitamin C, L-ascorbic Acid helps neutralize free radicals, minimize the look of fine lines and wrinkles, and brighten skin tone. HOW DO I USE OBAGI PROFESSIONAL-C SERUM 20%? Apply 5 to 7 drops of Obagi Professional-C Serum to the face, neck and chest using fingertips. Apply to cleansed skin in the morning before sunscreen and makeup application. A slight tingling may occur in some people, which diminishes with continued use.