Huwentoxin-IV TFA is a potent, selective blocker of sodium channels, specifically inhibiting neuronal Nav1.7, Nav1.2, Nav1.3, and Nav1.4 with IC50 values of 26, 150, 338, and 400 nM, respectively. It preferentially targets the peripheral nerve subtype Nav1.7 by interacting with neurotoxin receptor site 4, demonstrating analgesic effects in animal models of inflammatory and neuropathic pain [1] [2].