Ipamorelin

Educational overview

Ipamorelin is listed in the ezGLP knowledgebase under GH secretagogue. Evidence and regulatory status can vary by formulation, route, and jurisdiction.

Ipamorelin is a synthetic pentapeptide growth hormone secretagogue developed by Novo Nordisk in the 1990s. It is an agonist at the ghrelin receptor GHS-R1a and triggers growth hormone release from the pituitary through the same pathway as GHRP-6 and GHRP-2, but Raun and colleagues described it in 1998 as the first selective growth hormone secretagogue because, in their models, it did not meaningfully raise ACTH, cortisol, or prolactin at GH-releasing doses. That selectivity, together with a comparatively mild effect on appetite, is the main reason ipamorelin became the most widely compounded ghrelin mimetic and a common partner for GHRH analogues such as sermorelin and CJC-1295.

Human evidence is small and largely pharmacological. Gobburu and colleagues published a pharmacokinetic and pharmacodynamic model from healthy volunteers in 1999, describing a plasma half-life of roughly two hours and dose-related GH release. Helsinn later studied ipamorelin for postoperative ileus after bowel resection: Beck and colleagues' 2014 randomised, placebo-controlled proof-of-concept study found it well tolerated, but the subsequent phase II program did not meet its endpoints and development was discontinued. There are no controlled trials of ipamorelin for body composition, sleep, recovery, or aging in healthy adults, and long-term safety data do not exist, as Sigalos and Pastuszak noted in their 2018 review.

Ipamorelin has no marketing approval from the FDA, the EMA, or comparable regulators, and it is available in the United States only as a compounded or research-labelled product in injectable, nasal, and oral forms. The FDA has placed ipamorelin acetate among bulk drug substances that may present significant safety risks in compounding, citing an unnatural amino acid, immunogenicity potential from aggregation or peptide impurities, and published reports of serious adverse events including death with intravenous administration; its Pharmacy Compounding Advisory Committee reviewed the nomination in October 2024. The World Anti-Doping Agency names ipamorelin explicitly on its Prohibited List under section S2.2.4.

Compounded ipamorelin is most often supplied as a lyophilised powder reconstituted with bacteriostatic water for subcutaneous injection, either alone or blended in a fixed ratio with CJC-1295 or sermorelin. No approved label sets storage or beyond-use limits, and no published stability data cover reconstituted solutions, so the compounding pharmacy's documentation is the only formal reference. Because human studies show the GH pulse is brief and the half-life is about two hours, dose logs for ipamorelin commonly record the clock time of each administration relative to meals and sleep, together with lot number, reconstitution date, concentration produced, and storage temperature; for blends the record also captures the stated component ratio.

Category

GH secretagogue

Routes represented

Subcutaneous (SubQ)

Approximate library half-life

2 hours; formulation-dependent and not dosing guidance

Storage context

Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.