This peptide is a modified fragment of hGH which contains the portion of the molecule that is believed to be responsible for hGH’s anti-obesity effects. The peptide has been shown to increase fat burning without the increase in blood sugar and growth rate that has been seen with hGH itself. AOD 9604 has been deemed safe for chronic use by the FDA, receiving Human GRAS status in 2014. In addition to its utility as an anti-obesity peptide, AOD 9604 has been shown to have very favorable cartilage repair and regenerative properties, especially when paired with peptide BPC 157.
The effect of GHSs on GH release is dose dependent and more reproducible than that of GHRH. The peptide GHSs (e.g., GHRP-6, GHRP-1, GHRP-2, and hexarelin) and the nonpeptide GHSs differ in terms of their pharmacokinetics. The nonpeptides MK-0677 and macimorelin have been developed specifically as orally active agents. The peptidyl GHSs are also active PO, but only at doses several hundred times higher than that required when administered IV.
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.