Medik8's revolutionary Vitamin CE serum is highly stable and works to combat sun related skin damage. Vitamin C works to maintain collagen production, increase the skin's elasticity and density, as well as improve the skin’s texture and brighten the complexion. The Medik8 CE Tetra contains a medium strength concentration of lipid soluble vitamin C which is ideal for penetration and stability. CE-Tetra contains vitamin E which boosts the overall antioxidant effect. With more than double level of vitamin C is included in CE-Tetra formula compared with C-Tetra. Medik8 CE Tetra is highly potent and safe to use. The CE Tetra formula is ideal for those of any age who are seeking a high strength vitamin C serum, and perfect for those in their 40's or above who want to use a strong concentration of Vitamin C from the get-go.