Joshua E.Verified buyer
Jun 20, 2026
★★★★★
Pure!
Works as intended
Research summary
Ipamorelin — clinical & mechanistic profile
Ipamorelin is the first GHRP with GHRH-like selectivity, binding GHSR-1a (ghrelin receptor) to stimulate pulsatile GH release with EC50 = 1.3 nmol/L and Emax = 85% comparable to GHRP-6, but without ACTH/cortisol elevation even at >200-fold above GH ED50. Lower plasma clearance (5-fold slower than GHRP-6) with ~50% nasal bioavailability.
Research status
clinical investigational
Sequence
Aib-His-D-2-Nal-D-Phe-Lys-NH2
Molecular weight
711.85 g/mol
Molecular formula
C38H49N9O5
Studied applications
- •Exceptional selectivity: no significant ACTH/cortisol elevation at >200-fold GH ED50, mirroring GHRH selectivity
- •GHRP-6 equivalent potency: EC50 = 1.3 ± 0.4 nmol/L, Emax = 85 ± 5% in rat pituitary; ED50 = 80 nmol/kg in vivo
- •Pulsatile GH release: dose-dependent peaks at 15-60 min, baseline by 180 min; synergistic with GHRH
- •Superior pharmacokinetics: 5-fold lower plasma clearance than GHRP-6, ~50% nasal bioavailability
- •GI-independent action: gastrectomy reduces GHRP-6 GH release 60-70%, suggesting gastric ghrelin component
Mechanisms of action
- •GHSR-1a agonism: selectively binds ghrelin receptor, confirmed via GHRP antagonist pharmacology (not GHRH pathway)
- •Pituitary somatotroph activation: directly stimulates GH-producing cells via Gq-protein/calcium signaling
- •Hypothalamic modulation: may upregulate GHRH mRNA in arcuate nucleus, downregulate somatostatin in periventricular nucleus
- •Calcium influx: triggers intracellular Ca2+ signaling from IP3-mediated stores for GH vesicle release
- •Pathway selectivity: minimal cross-talk to ACTH-releasing or prolactin-releasing pathways
- •Synergistic with GHRH: amplifies GH pulse through complementary cAMP (GHRH) and Ca2+ (ipamorelin) pathways
Research constraints & safety notes
- •Not approved for human therapeutic use—research compound only
- •Clinical development for postoperative ileus discontinued
- •Short half-life (~2 hours) requires multiple daily administrations
- •GH elevation may affect glucose metabolism
- •Quality and purity of research compounds varies between sources
Peer-reviewed references
- Raun K, et al. — Ipamorelin selectivity and GH secretion (1998)PMID: 9849822View
- Ipamorelin vs. other GHRPs selectivity comparison (2001)PMID: 11452249View
- Pharmacokinetics and mechanism studiesPMID: 16352683View
- GHRPs hypothalamic GHRH/somatostatin modulationPMID: 8950613View
- Ipamorelin pharmacokinetics, nasal bioavailabilityPMID: 9879640View
For research use only. This summary is a research-scientific overview compiled from peer-reviewed sources. It is not medical advice and is not intended for human or veterinary consumption.
Related products