Norverapamil-d6 (()-Norverapamil-d6) hydrochloride is deuterium labeled Norverapamil (hydrochloride). Norverapamil hydrochloride (()-Norverapamil hydrochloride), an N-demethylated metabolite of Verapamil, is a L-type calcium channel blocker and a P-glycoprotein (P-gp) function inhibitor[1][2][3].