Lenomorelin (Ghrelin) is a pleiotropic hormone, whose effect on growth hormone secretion, through the growth hormone secretagogue (GHS) receptor, is one of its many actions. It is synthesized principally in the stomach. Ghrelin-producing cells constitute a distinct group of endocrine cells dispersed throughout the gastric mucosa and to a lesser extent in the small intestine and the endocrine pancreas. Ghrelin plasma levels rise during fasting and chronic caloric restriction to stimulate food intake and fat storage and to prevent life-threatening falls in blood glucose. Plasma ghrelin levels decrease after a meal is consumed and in conditions of energy surplus (such as obesity). Ghrelin has emerged as a key player in the regulation of appetite and energy homeostasis. It stimulates food intake and transduces signals to hypothalamic regulatory nuclei that control energy homeostasis. Ghrelin levels are negatively correlated with body mass index (BMI) and insulin resistance. Lenomorelin is a peptide of 28 amino acids, in which the serine 3 residue is n-octanoylated, which is necessary for biological activity.