Ipamorelin is a synthetic pentapeptide research compound that engages the growth hormone secretagogue receptor type 1a, more commonly written as GHS-R1a or the ghrelin receptor. In preclinical work, ipamorelin is studied for its selective activation profile at GHS-R1a, which drives a measurable growth hormone pulse in animal models without the cortisol and prolactin elevations seen with earlier secretagogues. This selectivity has made the ipamorelin ghrelin receptor interaction a useful tool for investigators isolating GH-pathway effects from broader pituitary axis activation. For wider context on the peptide and the cluster it sits within, see our ipamorelin selective GHRP overview and the CJC-1295 / Ipamorelin blend research summary.
Ipamorelin and GHS-R1a: Selective Growth Hormone Secretagogue Research
CJC-1295 / Ipamorelin · Published April 29, 2026 · Updated April 30, 2026 · 7 min read
Quick Answer
Ipamorelin is a synthetic pentapeptide that selectively activates the ghrelin receptor GHS-R1a in research models. Studies show that this binding stimulates growth hormone release with minimal measurable effect on cortisol and prolactin, distinguishing ipamorelin from earlier growth hormone secretagogues. For research use only, not for human or veterinary application.
Research Use Only. All products are strictly for research use only (RUO). Not for human consumption. Products on this site are not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA. By purchasing, you agree that you are a qualified researcher and that products will be used solely for in-vitro research purposes.
- What Is Ipamorelin and How Does It Engage the Ghrelin Receptor?
- How Does GHS-R1a Activation Drive Growth Hormone Release in Research?
- Why Does Ipamorelin Show Minimal Cortisol and Prolactin Response?
- What Preclinical Models Use Ipamorelin to Study GHS-R1a Signaling?
- How Does Ipamorelin Compare to Other GHS-R1a Agonists in Research?
- What Should Researchers Consider When Sourcing Ipamorelin for GHS-R1a Studies?
- Frequently Asked Questions
- Related Research Reading
- Frequently Asked Questions
- Glossary
Frequently Asked Questions
What is Ipamorelin in research contexts?
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Ipamorelin is a synthetic pentapeptide and selective ghrelin receptor (GHS-R1a) agonist. It is studied in research models as a growth hormone secretagogue with minimal effects on cortisol or prolactin secretion.
What makes Ipamorelin selective for the ghrelin receptor?
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Ipamorelin binds GHS-R1a with affinity comparable to ghrelin but lacks structural elements that activate cortisol- or prolactin-stimulating pathways. This selectivity profile, validated in pituitary research, distinguishes it from older GHRPs like GHRP-6.
How is Ipamorelin selectivity measured in research?
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Selectivity is assessed by measuring GH versus cortisol, ACTH, and prolactin responses to Ipamorelin in pituitary cell cultures and rodent in vivo studies. Ipamorelin uniquely produces robust GH release without elevating these other hormones.
Is Ipamorelin approved for human use?
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No. Ipamorelin is not approved by the FDA for any human therapeutic use. It is supplied strictly for in-vitro and preclinical research purposes by qualified investigators.
Glossary
Key terms used in this article.
- GHS-R1a
- Growth hormone secretagogue receptor 1a, the ghrelin receptor through which ipamorelin signals.
- GHRP
- Growth hormone-releasing peptide, a class of synthetic ghrelin receptor agonists that stimulate GH release.
- Ghrelin
- The endogenous 28-amino-acid acylated peptide hormone that activates GHS-R1a and stimulates appetite and GH release.
- Selectivity
- The pharmacological preference of a ligand for one receptor or pathway over others, minimizing off-target effects.
- Prolactin
- An anterior pituitary hormone primarily involved in lactation and reproduction, sometimes elevated by older GHRPs.
- Pentapeptide
- A peptide consisting of five amino acid residues; Ipamorelin's structure is Aib-His-D-2-Nal-D-Phe-Lys-NH2.
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Research Use Only. All products are strictly for research use only (RUO). Not for human consumption. Products on this site are not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA. By purchasing, you agree that you are a qualified researcher and that products will be used solely for in-vitro research purposes.
