What is the ghrelin receptor?
The ghrelin receptor — also called GHSR-1a (growth hormone secretagogue receptor type 1a) — sits on pituitary somatotroph cells, on gastric tissue, and on appetite-regulating central nervous system regions, where it operates as a G-protein-coupled receptor. The molecular target of ipamorelin and the broader growth hormone secretagogue compound class.
What the research literature says
The GHSR-1a receptor was first characterised as the receptor for endogenous ghrelin — a 28-amino-acid acylated peptide hormone secreted from gastric oxyntic cells. The receptor signals through Gαq with downstream IP3, DAG, and calcium-flux engagement. On pituitary somatotroph cells, GHSR-1a activation produces a discrete GH-release pulse; on appetite-regulating CNS regions, GHSR-1a activation drives orexigenic (appetite-stimulating) effects.
Synthetic GHSR-1a agonists — the growth hormone secretagogue compound class — engage the receptor without engaging the parallel orexigenic appetite pathway via the same signalling specificity. The Raun ipamorelin characterisation paper established the selectivity profile that distinguishes ipamorelin from earlier-generation GHSR agonists (PMID 9849822). The pharmacokinetic framework was characterised in the Johansen study (PMID 9879640). The Venkova rodent postoperative-ileus work documented prokinetic activity via gastric GHSR-1a engagement (PMID 19289567).
The combined CJC-1295 + Ipamorelin protocol pairs GHSR-1a engagement (from ipamorelin) with GHRH-receptor engagement (from CJC-1295) on the same pituitary somatotroph cells to drive additive GH release.
Why this matters in research context
The ghrelin receptor matters in peptide-research contexts as the molecular target of the GH secretagogue compound class. Researchers studying GH-axis pharmacology with ipamorelin should anchor protocol design to GHSR-1a engagement; the parallel GI-motility effects (via gastric GHSR-1a engagement) are the basis for the alternative postoperative-ileus research application.
Related compounds
- Ipamorelin 10mg — selective GHSR-1a agonist
- CJC-1295 + Ipamorelin Blend — combined ghrelin + GHRH receptor engagement
Related research questions
References
- Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol 1998;139(5):552-561. [PMID 9849822]
- Johansen PB et al. Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption. Xenobiotica 1998;28(11):1083-1095. [PMID 9879640]
- Venkova K et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. J Pharmacol Exp Ther 2009;329(3):1110-1116. [PMID 19289567]
Research-questions pages describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. Every compound in the Ronin catalog is sold strictly for laboratory and research use only.