About the brand: Powerful skincare backed by science and innovation. 1oz Obagi System Professional-C 10% Vitamin C Serum The 10 percent L-ascorbic acid helps in defending against damaging UVA and UVB rays, helps prevent premature signs of aging such as fine lines and wrinkles, and contributes to collagen synthesis. Ingredients: Propylene glycol, water, propylene carbonate, ascorbic acid, fragrance. Made in the USA