Cellex-C serum contains 10% vitamin C in the form of L-ascorbic acid. This is the only form of vitamin C that is biologically useful to the skin. With continued use your skin will look and feel the way it did when you were younger. Although scientists have known for many years the importance of vitamin C to the skin, taking vitamin C orally does not necessarily provide benefits. Until now the technology has not existed to allow a stabilized form of vitamin C to penetrate the skin. Advanced Cellex-C High Potency Serum $128.00 Cellex-C Skin Firming Cream $128.00 GLA Extra Moist $73.00