NHC-diphosphate triammonium is an active phosphorylated intracellular metabolite of β-d-N4-Hydroxycytidine (NHC) (HY-125033) as a diphosphate form[1]. NHC-diphosphate triammonium is a weak alternative substrate for the viral polymerase and can be incorporated into HCV replicon RNA[1][2].