Growth Hormone · 5mg × 10 vials
Ghrelin mimetic. Similar profile to GHRP-2 with stronger ghrelin-receptor appetite signaling.
GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) is a synthetic hexapeptide developed by Cyril Bowers and Frank Momany in the early 1980s, the original growth hormone releasing peptide that defined the class. It binds the growth hormone secretagogue receptor (GHS-R1a) on pituitary somatotrophs and on hypothalamic neurons that drive feeding behaviour, triggering a pulse of growth hormone release and a strong central appetite signal. The same receptor was identified in 1999 as the endogenous target of ghrelin, which is why GHRP-6 is best understood as a ghrelin mimetic.
What separates GHRP-6 from the later, more selective GHRPs (ipamorelin, and to a lesser extent GHRP-2) is the breadth of its receptor activity. At GH-releasing exposures, GHRP-6 also meaningfully elevates ACTH, cortisol, and prolactin through downstream HPA activation, and its orexigenic signal is the strongest in the class. Ipamorelin, developed in 1998 specifically to address this, releases GH at similar potency without the cortisol and prolactin rise and without the pronounced appetite effect. GHRP-6 retains a research niche in contexts where appetite stimulation is itself the endpoint, including cancer cachexia, HIV-associated wasting, and post-surgical anorexia models.
What the published studies measured.
Peer-reviewed studies and clinical guidelines - tap any to read the source.
:1537-1545, PMID 6714155](https://pubmed.ncbi.nlm.nih.gov/6714155/) - the foundational synthesis paper, Bowers/Momany's original characterization of the GHRP-6 hexapeptide
Read study ↗PubMedSmith RG, Van der Ploeg LH, Howard AD et al. Peptidomimetic regulation of growth hormone secretion. Endocr Rev 1997, 18(5):621-645:621-645](https://pubmed.ncbi.nlm.nih.gov/9331545/) - review of the GHRP class through 1997, before ghrelin was identified, contextualizes GHRP-6's positioning
Read study ↗PubMedKojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature 1999, 402(6762):656-660:656-660](https://pubmed.ncbi.nlm.nih.gov/10604470/) - the discovery paper for ghrelin as the endogenous GHS-R1a ligand, retroactively explains GHRP-6's appetite signal
Read study ↗PubMedRaun K, Hansen BS, Johansen NL et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol 1998, 139(5):552-561, PMID 9849822:552-561, PMID 9849822](https://academic.oup.com/ejendo/article-abstract/139/5/552/6748390) - the ipamorelin paper that directly compared selectivity against GHRP-6 in pigs, established the cortisol/prolactin gap that drove ipamorelin to become the default GHRP
Read study ↗PubMedLocatelli V, Torsello A. Growth hormone secretagogues: physiological role and clinical utility. Endocrine 2014, 47(3):788-803:788-803](https://pubmed.ncbi.nlm.nih.gov/24846777/) - review covering clinical positioning of GHRP-6 in cachexia, wasting, and frailty contexts
Read study ↗PubMedNass R et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Ann Intern Med 2008, 149(9):601-611:601-611](https://pubmed.ncbi.nlm.nih.gov/18981485/) - MK-677 / ibutamoren data, the comparator for chronic GHS-R1a agonism vs the GHRP-6 acute-pulse approach
Read study ↗Storage: refrigerated, ~30 days after reconstitution. Unreconstituted vials stable at room temperature short-term, refrigerate for long-term storage. Do not freeze reconstituted vials. Allow refrigerated vials to reach room temperature for a couple of minutes before injecting.