Nature's Bounty Nature's Bounty Immune 24 Hour +, The only Vitamin C with 24 Hour Immune Support from Ester C, Rapid Release Softgels, 50 Count24 HOUR IMMUNE SUPPORT: Nature's Bounty Immune 24 Hour + contains the only clinically studied Vitamin C with 24 hour immune support from Ester C (1) SUPPORTS UPPER RESPIRATORY HEALTH: Highly bioavailable Ester C can increase Vitamin C levels in the body which is important for white blood cell function and contributes to the health of the upper respiratory tract (1) WITH ELDERBERRY AND ECHINACEA: Nature's Bounty Immune 24 Hour + rapid release softgels