Phrixotoxin 3 TFA is a potent inhibitor of voltage-gated sodium channels, demonstrating IC50 values of 0.6 nM for NaV1.2, 42 nM for NaV1.3, 72 nM for NaV1.4, 288 nM for NaV1.1, and 610 nM for NaV1.5, respectively. This compound modulates the activity of these channels similarly to traditional gating-modifier toxins, inducing a depolarizing shift in gating kinetics as well as obstructing the inward sodium current.