Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue receptor (GHSR). Ibutamoren is an orally-active, non-peptidic agonist of GHSR (Kd = 0.4 nM) and, as a result, is a GH secretagogue. It elevates GH in dogs after oral doses as low as 0.125 mg/kg, without significantly changing plasma levels of aldosterone, luteinizing hormone, thyroxine, or prolactin.