An inhibitor of VMAT2 that is selective over VMAT1 (Kis = 97 and >20,000 nM, respectively, in a serotonin uptake assay); dose-dependently reduces levels of the monoamines norepinephrine, dopamine, and 5-HT in rat brain; has been used to induce depressive-like behavior in animal models; improves performance in balance beam and rotarod tests and prevents decreases in the number of striatal MSNs in a YAC128 transgenic mouse model of Huntington’s disease at 5 mg/kg