Ipamorelin

Research Overview

Ipamorelin is a receptor-selective GH secretagogue, studied wherever a defined ghrelin receptor ligand is needed without the ACTH, cortisol or prolactin co-release reported for GHRP-2 and GHRP-6:

• Selective GHS-R1a receptor pharmacology and GH-axis investigations
• Pulsatile GH secretion and secretory-rhythm modelling
• IGF-1 axis signalling in cell and tissue models

How Ipamorelin Works: GHS-R1a Selectivity

Ipamorelin binds the ghrelin receptor (GHS-R1a) on somatotrophs in the anterior pituitary with high affinity. The receptor is Gq-coupled: activation drives phospholipase C, raises intracellular calcium and triggers exocytosis of stored GH secretory granules.

The selectivity is what sets it apart. Older secretagogues like GHRP-2 and GHRP-6 also engage corticotropin-releasing-hormone (CRH) pathways, which elevate ACTH and cortisol. Ipamorelin is described as selective because, unlike GHRP-2 and GHRP-6, its GHS-R1a activation is reported not to co-stimulate ACTH, cortisol or prolactin release in preclinical studies.

Receptor Comparison with CJC-1295

Ipamorelin (GHS-R1a agonist) and CJC-1295 (GHRH receptor agonist) act through different receptors on the same pituitary somatotrophs:

• GHRH receptor activation (CJC-1295) raises cAMP via Gs coupling.
• GHS-R1a activation (ipamorelin) raises intracellular calcium via Gq coupling, triggering secretory granule fusion.

Milo-Lab lists an Ipamorelin + CJC-1295 blend as a separate product.

Downstream Signalling

Released growth hormone binds the GH receptor and signals through JAK2/STAT5. Hepatic IGF-1 expression follows and mediates much of the downstream transcriptional response.

Storage

Lyophilised vials: store at -20°C, protected from light.

For research purposes only. Not for human consumption.