Cobalt PeptidesResearch Grade

Scientific Reference

Ipamorelin

Evidence profile: Human Phase 2 evidence

Ipamorelin is a synthetic pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, that acts as an agonist at the ghrelin receptor, GHS-R1a. It was derived from earlier growth hormone-releasing peptides and is one residue shorter than GHRP-2 and GHRP-6. What set it apart in the original animal pharmacology was selectivity: growth hormone release was not accompanied by the rises in ACTH and cortisol recorded for older compounds in the class. Because ghrelin receptors are also present in the gut, it has been examined in rodent models of gastrointestinal motility, and it has been the subject of a small number of human clinical studies. Human data remain limited, and most of what is known comes from animal work.

Mechanism of Action

Ipamorelin has been reported to bind GHS-R1a on somatotroph cells of the anterior pituitary, where receptor activation raises intracellular calcium and triggers growth hormone secretion. Its reported selectivity concerns other pituitary and adrenal hormones: in the animal studies that first characterised it, ACTH and cortisol did not rise appreciably, unlike with GHRP-6 or GHRP-2. The structural basis for this difference has not been fully explained. The receptor is also found in the gut wall and its nerve supply, which is the rationale for rodent studies of gastrointestinal transit using this compound.

Molecular Information

  • Type: Growth hormone secretagogue (GHRP)
  • Length: 5 amino acids
  • Molecular weight: 711.9 g/mol
  • Molecular formula: C38H49N9O5
  • CAS: 170851-70-4

Published Research

  • Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients

    Beck DE et al. · International journal of colorectal disease · 2014 · Clinical

    PMID 25331030 — View on PubMed

  • Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers

    Gobburu JV et al. · Pharmaceutical research · 1999 · Clinical

    PMID 10496658 — View on PubMed