Obagi Professional-C Vitamin Serum 20% L-ascorbic Acid 30ml / 1oz The earlier you add a vitamin C serum to your routine, the longer your complexion will remain youthful and radiant. Obagi Professional-C Serum 20 is a concentrated serum with 20% vitamin C that provides multiple benefits for the complexion. This ingredient neutralizes free radicals that break down collagen and elastin causing damage and leading to fine lines, wrinkles and dark spots. Vitamin C also promotes collagen production Brand New,sealed EXP:06/25