This exquisite lightweight oil-based (no water or preservatives) serum brightens, firms, evens skin tone, and reduces the look of wrinkles. The advanced Skin Optimized Vitamin C Serum contains one of the most stable forms of vitamin C (tetrahexyldecyl ascorbate) at 10% concentration in a highly-absorptive formula to leave your skin exceptionally soft, brightened, and luminous.