Growth hormone-releasing peptide 6 (GHRP-6) (developmental code name SKF-110679), also known as growth hormone-releasing hexapeptide, is one of several synthetic met-enkephalin analogues that include unnatural D-amino acids, were developed for their growth hormone-releasing activity and are called growth hormone secretagogues. They lack opioid activity but are potent stimulators of growth hormone (GH) release. These secretagogues are distinct from growth hormone releasing hormone (GHRH) in that they share no sequence relation and derive their function through activation of a completely different receptor. This receptor was originally called the growth hormone secretagogue receptor (GHSR), but due to subsequent discoveries, the hormone ghrelin is now considered the receptor's natural endogenous ligand, and it has been renamed as the ghrelin receptor. Therefore, these GHSR agonists act as synthetic ghrelin mimetics.