Growth hormone secretagogues: history, mechanism of action, and clinical development

Abstract

Growth hormone secretagogues (GHSs) are a generic term to describe compounds that increase growth hormone (GH) re-lease. GHSs include agonists of the growth hormone secretagogue receptor (GHS-R), whose natural ligand is ghrelin, and agonists of the growth hormone-releasing hormone (GHRH) receptor, to which the GHRH binds as a native ligand. Several GHSs have been developed with a view to treating or diagnosing of GH deficiency, which causes growth retardation, gastrointestinal dysfunction, and altered body composition, in parallel with extensive research to identify GHRH, GHS-R, and ghrelin. This review will focus on the research history and the pharmacology of each GHS, which reached randomized clinical trials. Further-more, we will highlight the publicly disclosed clinical trials regarding GHSs.