Sisu - Cold & Flu Rescue with Ester-C® - 60 Veggie Capsule(s) - NPN: 80026563 -- Use Cold & Flu Rescue with Ester C for the relief of cold and flu symptoms and of upper respiratory tract infection. Cold & Flu Rescue with Ester C is a unique combination of four powerful ingredients, Ester-C®, andrographis, NAC, and echinacea, each of them proven in human research to lessen the severity and duration of cold and flu symptoms.