GH PEPTIDES MONOGRAPH
Ipamorelin Research Monograph
Selective ghrelin-receptor pentapeptide — GHS-receptor pharmacology research
Ipamorelin is a synthetic pentapeptide and one of the most receptor-selective growth hormone secretagogues (GHS) characterised in published literature. The defining feature of its pharmacology is GH-release activity without measurable cortisol or prolactin effects in the published Raun et al. (1998) characterisation.
Origin and selectivity
Ipamorelin was developed at Novo Nordisk and characterised by Raun et al. in the European Journal of Endocrinology (1998). The defining experimental finding was selective GHS-receptor activation without the cortisol and prolactin elevations that accompany broader-spectrum GHRPs.
Sequence and structure
The published sequence is Aib-His-D-2Nal-D-Phe-Lys-NH2, where Aib is aminoisobutyric acid. Molecular weight is 711.9 g/mol. The compound is supplied for research as a sterile lyophilised powder, sealed under nitrogen.
Primary research literature
Published ipamorelin research focuses on GHS-receptor pharmacology, pulsatile GH secretion research, and stack-based research designs combining ipamorelin with GHRH analogues like CJC-1295 and sermorelin. The pentapeptide's selectivity makes it the preferred GHS in research designs that require clean isolation of GHS-receptor effects.
Comparison with GHRP-2 and GHRP-6
GHRP-2 and GHRP-6 are older hexapeptide GHRPs that show additional cortisol- and prolactin-stimulating activity at higher research doses. Ipamorelin's selectivity profile makes it the preferred tool when those off-axis effects would confound the research design. See /compare/ipamorelin-vs-ghrp-2 for direct comparison.
Storage, reconstitution, and handling
Lyophilised ipamorelin is stable for months at −20°C in its sealed vial. After reconstitution, store at 2–8°C and use within 7 days.
Quality and verification
VESPER ipamorelin is supplied as a 2mg lyophilised vial at ≥99.5% HPLC purity, with sequence identity confirmed by mass spectrometry on every batch.
Sequence
Aib-His-D-2Nal-D-Phe-Lys-NH2
Molecular weight
711.9 g/mol
CAS
170851-70-4
Purity
≥99.5%
Storage
−20°C, protected from light
Vial format
2mg / vial
Frequently asked
What makes ipamorelin selective?
Ipamorelin produces GH release without measurable cortisol or prolactin elevation in the Raun et al. (1998) characterisation, distinguishing it from broader-spectrum GHRPs that engage additional pituitary axes.
Can ipamorelin be combined with CJC-1295 in research?
Yes — pairing a GHRH analogue (like CJC-1295) with a selective GHS (like ipamorelin) is a published research design. VESPER's Growth Hormone Stack bundles them together with MK-677.
What is the molecular weight of ipamorelin?
711.9 g/mol for the 5-amino-acid peptide.
⚠ For research use only. Not for human consumption.