Orexin A human, rat, mouse, a 33 amino acid excitatory neuropeptide, orchestrates diverse central and peripheral processes. Orexin A human, rat, mouse is a specific, high-affinity agonist for G-protein-coupled receptor OX1R. Orexin A human, rat, mouse has a role in the regulation of feeding behavior. Orexin A human, rat, mouse is an effective anti-nociceptive and anti-hyperalgesic agent in mice and rats.