CLP257 is a selective K+-Cl− cotransporter KCC2 activator (EC50: 616 nM) and it is inactive against NKCC1, GABAA receptors, KCC1, KCC3 or KCC4. CLP257 alleviates hypersensitivity in rats with neuropathic painc and it also modulates plasmalemmal KCC2 protein turnover post-translationally. CLP257 restores impaired Cl− transport in neurons with diminished KCC2 activity.