This Solgar Ester-C Plus 500 Immune Boost formulation is designed to support robust immune function. Ester-C is a uniquely buffered, non-acidic form of Vitamin C, which means it is gentle on the stomach. It is formulated to provide sustained levels of Vitamin C as it is absorbed and utilized by the body. This supplement is ideal for daily maintenance of healthy immune defenses or for extra support during periods of increased stress.