SkinMedica Vitamin C + E Complex utilizes water soluble silicon gel, aqueous form of Vitamin C (Ascorbic Acid), to be gradually released throughout the day. The lipid soluble form of Vitamin C (Tetrahexyldecyl Ascorbate) diffuses directly into the skin for antioxidant defense. SkinMedica Vitamin C + E Complex. Fights, improves, prevents sun damage. Improves skin tone, texture and firmness. In the morning, apply 1-2 drops to fingertips and gently smooth onto face and neck with an upward stroke. Use after TNS Recovery Complex. A mild, temporary stinging is normal