What Is Ipamorelin? Selective Ghrelin Agonist Research Guide
Ipamorelin is a synthetic pentapeptide and a selective agonist of the ghrelin receptor (GHS-R1a). Among the growth hormone secretagogues it is the one most often chosen for research where a clean signal matters, because it shows comparatively little activity on cortisol and prolactin pathways in published work.
Structure and class
Ipamorelin has the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2 and a molecular weight of approximately 711.9 g/mol. It belongs to the growth hormone releasing peptide (GHRP) class alongside GHRP-2, GHRP-6 and Hexarelin.
Unlike the older GHRPs, Ipamorelin is described in the literature as highly selective for GHS-R1a, which is the basis of most comparisons made against it.
How it compares with other secretagogues
GHRP-6 is studied for a pronounced appetite-stimulating effect through ghrelin signalling. GHRP-2 is more potent at growth hormone release but shows more off-target activity in published work. Hexarelin is the most potent but shows the most receptor desensitisation over time.
Ipamorelin sits at the selective, lower-potency end. Research designs pick it when the aim is to isolate the growth hormone axis without confounding hormonal variables.
Preparation and storage
Supplied lyophilised, reconstituted with bacteriostatic water. Standard peptide handling applies: gentle swirling, no shaking, refrigerate after reconstitution, protect from light, avoid freeze-thaw cycling.
Frequently asked questions
- Is Ipamorelin a GHRH analogue?
- No. Ipamorelin is a ghrelin receptor (GHS-R1a) agonist, a different receptor from GHRH analogues such as CJC-1295 or Sermorelin. That is why the two classes are often studied together.
- Why is Ipamorelin described as selective?
- Published comparisons show minimal effect on cortisol and prolactin relative to older GHRPs such as GHRP-2 and Hexarelin, which makes it useful when a study needs to isolate a single pathway.
All information on this page is provided for laboratory and educational reference only. Peptides Lab SA (PTY) Ltd supplies compounds strictly for in-vitro research use. Nothing here is medical advice, a dosing recommendation, or a claim of human safety or efficacy.