Cellex-C Core Formulations are medical grade superheroes, each with a specific mission, and virtually guaranteed to help you look 5-10 years younger. They contain from 5-15% L-ascorbic acid (Vitamin C) as well as the full complement of Cellex-C complex signature ingredients. L-ascorbic acid is the only form of Vitamin C the body can recognize and use for collagen production, which makes Cellex-C Core Formulations some of the most potent skin care products available.