Ester-C 1000mg Tablets provide the support you can count on all day, every day. A daily dose of Ester-C gets into your white blood cells, and stays there – for up to 24 hours, which is longer than regular Vitamin C.(2) Plus, Ester-C is manufactured without chemicals to neutralize pH, which means it’s non- acidic and gentle on your stomach. (1)These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure or prevent any disease. (2) Ester-C Vitamin C has been clinically studied to stay in your white blood cells for up to 24 hours, which is longer than regular Vitamin C. White blood cells are an important component to the immune system.