24-Hour Immune Support; Ester-C is a unique Vitamin C formula that delivers 24-hour immune support, so one daily serving of 1000 mg is all you need Potent Antioxidant; As an antioxidant, Ester-C helps fight free radicals, which can cause oxidative stress that may lead to the premature aging of cells Gentle On The Stomach; Ester-C's water-based manufacturing process neutralizes pH, making it non-acidic and gentle on the stomach