Ester-C is a unique breakthrough Vitamin C formula supported with naturally occurring metabolites. It is a potent antioxidant that works to support our immune system by fighting free radicals. The damaging effects of free radicals are responsible for the premature aging of metabolic cells. White blood cells are an important part of the immune system, and use Ester-C as a key nutrient in this mechanism. Ester-C delivers the active immune support system you can depend on.