UCPH-101 is a noncompetitive inhibitor of excitatory amino acid transporter 1 (EAAT1), which takes up extracellular glutamate in the central nervous system. UCPH-1 is selective for EAAT1 over EAAT2 and EAAT3 with IC50 values of 0.66, >300, and >300 μM, respectively, in a radioligand uptake assay using HEK293 cells transfected with the human transporter. It selectively inhibits anion currents in tsA201 cells expressing human EAAT1 (Kd = 0.34 μM) over rat EAAT4 and mouse EAAT5 at concentrations up to 10 μM. UCPH-101 is orally bioavailable in rats at a dose of 10 mg/kg but does not cross the blood-brain barrier.