The Vitamin C Serum utilizes a stabilized form of vitamin C called sodium ascorbyl phosphate (SAP) alongside vitamin E and ferulic acid to create a potent, antioxidant-rich treatment for all skin types! The Vitamin A Serum utilizes a next-generation form of vitamin A called HPR that is a gentle, yet effective way to smooth the appearance of fine lines and wrinkles as well as diminish the appearance of discoloration. We recommend using the Vitamin C Serum in the morning and the Vitamin A Serum at night for best results.