Ipamorelin

Mechanism (as reported)

A pharmacology profile reported that ipamorelin stimulates GH release via a GHRP-like receptor (PMID 9849822). A PK/PD modeling study in humans described that ipamorelin induces episodic GH release after administration (PMID 10496658).

Key findings (each cites a source)

• Ipamorelin was described as a growth-hormone-releasing pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) with GH-releasing potency/efficacy assessed in vitro and in vivo, and its GH release profile was characterized as similar to GHRP-6 and mediated via a GHRP-like receptor (PMID 9849822). [PMID 9849822]
• In adult female rats, research reported that ipamorelin increased longitudinal bone growth rate in a dose-dependent manner and assessed several bone-related endpoints (PMID 10373343). [PMID 10373343]
• A pharmacokinetic/pharmacodynamic modeling study in human volunteers reported dose-proportional PK parameters, a short terminal half-life (~2 hours), and episodic GH release after ipamorelin exposure, with an indirect response model to describe the concentration–GH relationship (PMID 10496658). [PMID 10496658]
• In young adult female rats, research reported that continuous ipamorelin treatment increased bone mineral content in vivo (DXA measurements) and increased/altered bone dimensions and cortical bone cross-sectional area in analyses that were also reported as not changing certain volumetric density measures (PMID 10828840). [PMID 10828840]
• Orthopaedics-focused reviews described ipamorelin as a growth hormone secretagogue activating IGF-1 signaling and satellite-cell repair, while emphasizing a lack of clinical trials for orthopaedic applications (PMID 41490200). [PMID 41490200]
• A narrative review on injectable peptide therapy in orthopaedics/sports medicine noted that while growth-hormone secretagogue approaches (including CJC-1295 + ipamorelin in murine models) showed muscle-related effects in animal studies, limitations included that findings were limited to animal studies and that clinical parameters such as indications and dosing remain unknown (PMID 41476424). [PMID 41476424]
• A review addressing approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance reported that, for many peptides marketed to patients (including ipamorelin), rigorous human safety data were scarce and potential for serious harm was discussed (PMID 41966639). [PMID 41966639]
• A review on growth hormone secretagogues in hypogonadal males discussed ipamorelin among GH/IGF-1 stimulators and stated that current clinical efficacy data are limited for understanding their role in hypogonadism-related body composition changes (PMID 32257855). [PMID 32257855]