Highly potent and selective nociceptin/orphanin FQ receptor (OP4) agonist peptide (pKi = 10.68; pEC50 = 9.80). Displays > 8000-fold selectivity over δ, κ, and μ opioid receptors and has relatively long lasting pronociceptive, hypotensive, negative inotropic and feeding stimulation effects in vivo.