Potent and selective orexin OX2 receptor agonist (EC50 = 28 nM at human OX2 expressed in CHO cells). Displays approximately 100-fold selectivity for OX2 over OX1 (EC50 = 2.75 μM at human OX1 expressed in CHO cells). Depolarizes OX2-expressing histaminergic neurons in mouse brain slices. Increases wake time in wild type mice. Suppresses cataplexy-like symptoms in OX knockout mice.