Ghrelin (acylated) itself shows a rather complex spectrum of effects on systemic metabolism, such as stimulation of gut motility, gastric acid secretion, regulation of glucose metabolism, inhibition of insulin secretion, increase of adiposity etc. Beside its role in reward seeking behavior, ghrelin modulates sleep, stress, anxiety, learning and memory performance, but also protection against muscle atrophy, improvement of some cardiocvascular functions, and role in retinopathy were described (for references see review [71]). Here, GHRL is linked to muscle atrophy.