A neuropeptide agonist of NMU1 and NMU2 (EC50s = 65 and 91 pM, respectively); induces phase shifts in the circadian rhythm of locomotor activity in rats (1 nmol, i.c.v.); inhibits the ability of neuropeptide Y, ghrelin, and ARP to stimulate food intake in rats by greater than 50% (1 nmol, i.c.v.); increases vasopressin levels 5-fold in rat plasma within five minutes and decreases urinary volume by 25% during the dark period (0.2 nmol, i.c.v.)