[Ala11,D-Leu15]-Orexin B(human) TFA is a potent, selective agonist for the orexin-2 receptor (OX2), demonstrating 400-fold higher selectivity for OX2 (EC 50 =0.13 nM) compared to the orexin-1 receptor (OX1) with an EC 50 of 52 nM.