Potent and selective Nav1.7 channel blocker (IC50 = 8, 11 and 171 nM for mouse, human and rat Nav1.7, respectively). Exhibits selectivity for Nav1.7 over other Nav1 channels (IC50 values are 0.11, 0.16, 0.85, 10, 11 and 25 μM for Nav1.2, Nav1.6, Nav1.1, Nav1.4, Nav1.3 and Nav1.5, respectively). Also exhibits selectivity over a panel of 81 other ion channels, receptors, enzymes and transporters. Blocks spontaneous firing of inherited erythromelalgia (IEM)-derived iPSC sensory neurons in vitro. Purity 98%. MW (observed): 672.56