GHRP-2 (and its siblings GHRP-1 and GHRP-6) are tiny synthetic peptides that reliably boost growth hormone (GH) when taken by injection or even by mouth. They work in both animals and humans, and the oral form can produce near‑maximal GH spikes. Combining a tiny dose of GHRP‑1 with the natural GH‑releasing hormone (GHRH) makes the effect even stronger.

A new class of small synthetic peptides has been developed which specifically release GH. They consist of 6-7 amino acids and release GH in animals as well as humans. So far 3 of these peptides have been administered to humans, i.e., GHRP-6, GHRP-1 and GHRP-2. As in rats, these 3 peptides have been found to be increasingly more effective in releasing GH in humans. All 3 GHRPs release GH more efficaciously than GHRH 1-44 NH2 in humans. Particularly note-worthy is that GHRP-6, GHRP-1 AND GHRP-2 all release GH after oral administration. Near maximal amounts of GH can be released after GHRP-1 and GHRP-2 oral administration. In the present studies, the GH responses and serum irGHRP levels after i.v., s.c. and oral administration have been determined in normal younger men and/or women. By each route of administration GH was very effectively released. Additionally, GH release was induced by oral GHRP-6 in children with various degrees of GH deficiency. Noteworthy is the synergistic release of GH induced by the combined i.v. bolus administration of 1 microgram/kg of GHRP-1 + GHRH 1-44NH2. Thus, these results demonstrate GHRPs' potential importance at the theoretical as well as pharmaceutical level.