The C15 Super Booster is a concentrated, light-as-water liquid treatment product designed to supercharge your Paula's Choice serum, or it may be used alone. This serum combines a blend of 15% stabilised Vitamin C (L-Ascorbic Acid), antioxidant Vitamin E, Ferulic Acid, & peptides to repair visible signs of ageing & stimulate collagen production for smoother, brighter & firmer looking skin.