Introduction to Ipamorelin
Ipamorelin is a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH₂) that acts as a selective ghrelin receptor agonist. It belongs to the growth hormone releasing peptide (GHRP) family but is noted for its high selectivity — it stimulates GH release without significantly raising cortisol, prolactin, or ACTH levels, which differentiates it from older GHRPs like GHRP-6.
Mechanism of Action
Ipamorelin binds to the ghrelin receptor (GHS-R1a) in the pituitary gland, stimulating growth hormone release in a pulsatile fashion that closely mimics natural GH secretion patterns. Its selectivity is attributed to its structural differences from other GHRPs that non-selectively activate multiple pathways.
Selectivity Profile
In animal studies comparing Ipamorelin to GHRP-2 and GHRP-6:
- Ipamorelin produced comparable GH release
- Minimal cortisol or ACTH elevation (unlike GHRP-6)
- No significant prolactin elevation
- No notable effect on appetite (unlike GHRP-6 which strongly increases appetite via ghrelin)
Research Applications
Ipamorelin is often studied in combination with CJC-1295, a GHRH analogue, as the two peptides work synergistically — CJC-1295 extends the GH release window while Ipamorelin amplifies the pulse.
Important Disclaimer
Ipamorelin is a research peptide. This information is for educational purposes only and does not constitute medical advice.
