Resist 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% stabilized Vitamin C (L-Ascorbic Acid), antioxidant Vitamin E, Ferulic Acid, and peptides to repair visible signs of aging and stimulate collagen production for smoother, brighter and firmer skin. Benefits: Vitamin C helps to even skin tone. Provides younger, healthier and more radiant skin. Can be used by all skin types.