P/OSPeptideOS evidence & status map
OPEN SOURCE MEDICINE FOUNDATIONLast reviewed 2026-10-10No dosing · no vendors · no advicesource file

← All compounds · evidence tier first, by design

Evidence tier for each claimed use · ← established · unknown →
UseE1E2E3E4E5E6E7E8
E3 Postoperative ileusE3
E6 Bone growth and bone mineral contentE6
E8 Muscle gain, fat loss, recovery, sleep and anti-ageing (gray-market claims)E8
Class C · Gray market

Ipamorelin

Pentapeptide Aib-His-D-2-Nal-D-Phe-Lys-NH2 (Aib, alpha-aminoisobutyric acid; D-2-Nal, D-2-naphthylalanine); contains non-standard and D-amino acids.

Non-standard residues or modifications: no plain one-letter sequence

Also: Ipamorelin acetate

A synthetic five-residue peptide that stimulates growth hormone release by acting on the ghrelin (growth hormone secretagogue) receptor. It was developed by Novo Nordisk in the 1990s and later tested by Helsinn as an intravenous treatment for postoperative ileus, where its published Phase 2 trial did not meet its efficacy endpoints. It is not approved anywhere checked and has no active sponsor. It is sold as a "research chemical" with claims of muscle gain, fat loss, recovery, sleep and "anti-ageing".

  • US C gray market
  • EU C gray market
  • UK ? not verified
  • CA C gray market
  • AU ? not verified
  • JP ? not verified
  • CN ? not verified

01Regulatory status, by jurisdiction

Standing notice. This compound is not approved as a medicine in any jurisdiction tracked here and has no active sponsor seeking approval. Material sold under this name, typically labelled “research chemical, not for human consumption”, is of unverified identity and purity and is not manufactured to pharmaceutical standards.
JurisdictionStatusDetail and primary source
USNot approvedNot approved: no application found in Drugs@FDA (openFDA query, retrieval date). Ipamorelin acetate was placed in Category 2 (significant safety risks) of FDA's 503B interim policy on 29 September 2023 and remains listed there. For 503A it appears on FDA's list of substances previously in Category 2 whose nominations were withdrawn by the nominators; FDA's safety statement remains on the page. FDA states it has no safety information for other injectable routes and lacks sufficient information to know whether it would cause harm.
“Compounded drugs containing Ipamorelin acetate may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation or peptide-related impurities.”
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of 04/22/2026) · retrieved 2026-10-10
USNot approvedIpamorelin does not appear in Category 1, 2 or 3 of FDA's list of bulk drug substances nominated for 503A compounding (updated 14 May 2026). It is not on the 503A bulks list and is not a component of any FDA-approved drug product.
“Category 1: Bulk Drug Substances Under Evaluation”
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (Updated May 14, 2026) · retrieved 2026-10-10
EUNot approvedNo product containing ipamorelin appears in EMA's downloadable medicines dataset (2,748 records, generated 10 Oct 2026), which covers centrally authorised medicines, refusals and withdrawn applications. National authorisations were not checked individually.
“This includes information on marketing authorisations of centrally authorised medicines and post-authorisation procedures.”
Download medicine data | European Medicines Agency (EMA) · retrieved 2026-10-10
CANot approvedQueries of Health Canada's Drug Product Database for the active ingredient and brand name ipamorelin returned no products under any status on the retrieval date.
“Search by drug identification number”
Drug Product Database online query · retrieved 2026-10-10
UK AU JP CNNot yet verified from a primary source. No status is shown rather than an unsourced one.

Sport (WADA): Prohibited · class S2.2.4. “growth hormone secretagogues (GHS) and their mimetics [e.g. anamorelin, capromorelin, ibutamoren (MK-677), ipamorelin, lenomorelin (ghrelin), macimorelin and tabimorelin]” WADA source

02What the human evidence shows

E3

Postoperative ileus

No randomised controlled trial in humans has been published for this use.

0published human RCTs
2published human trials
3registered studies
0with posted results

In a randomised, double-blind, placebo-controlled Phase 2 trial in 114 adults after bowel resection, intravenous ipamorelin did not significantly shorten time to tolerating a solid meal and showed no differences on secondary endpoints. A second, larger Phase 2 trial (NCT01280344, 320 enrolled, completed 2014) has no results posted on the registry and no publication was identified. In a rat model of postoperative ileus, intravenous ipamorelin shortened time to first bowel movement.

  • [1] No significant difference from placebo in time to first tolerated meal in 114 bowel-resection patients
  • [2] Shortened time to first bowel movement after laparotomy and intestinal manipulation in rats

Registered-study counts: ClinicalTrials.gov intervention search “ipamorelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.

E6

Bone growth and bone mineral content

No human trial of any design has been published for this use.

0published human RCTs
0published human trials
3registered studies
0with posted results

Rat studies only. Ipamorelin increased longitudinal bone growth in young rats and bone mineral content in adult female rats; in the adult rats the gain reflected larger bones, with volumetric bone density unchanged. No human bone study exists.

  • [3] Increased longitudinal bone growth in rats
  • [4] Increased bone mineral content via larger bone dimensions, without change in volumetric density, in adult female rats

Registered-study counts: ClinicalTrials.gov intervention search “ipamorelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.

E8

Muscle gain, fat loss, recovery, sleep and anti-ageing (gray-market claims)

No human trial of any design has been published for this use.

0published human RCTs
0published human trials
3registered studies
0with posted results

No human study has tested any of these outcomes. Human data are limited to a pharmacokinetic study in healthy men showing a single, short-lived rise in growth hormone after intravenous infusion. In mice, ipamorelin increased body fat rather than reducing it, an effect the authors attributed to GH-independent mechanisms such as increased feeding. Raised hormone levels are a laboratory measure, not evidence of muscle gain, fat loss or any health benefit.

  • [5] Single episode of GH release with a terminal half-life of about 2 hours after intravenous infusion in healthy men
  • [6] Increased relative body fat and fat pad weight in GH-deficient and GH-intact mice
  • [7] Product-identity finding, not efficacy: glycine-extended ipamorelin (Gly-ipamorelin) identified in black-market growth-promoting products

Registered-study counts: ClinicalTrials.gov intervention search “ipamorelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.

Key registered trials

NCTTitle (as registered)PhaseStatus
NCT00672074Safety and Efficacy of Ipamorelin for Management of Post-Operative Ileus2Completed
NCT01280344Safety and Efficacy of Ipamorelin Compared to Placebo for the Recovery of Gastrointestinal Function2Completed

03Safety signals

S3Limited human safety data

There are no adequate human safety data. The absence of reported harm is not evidence of safety.

  • Serious adverse events including death in an intravenous gastric-motility trial [8]
    FDA's compounding safety-risk summary states that a published study identified serious adverse events including death when ipamorelin was given intravenously for gastric motility. The published postoperative ileus trial reported treatment-emergent adverse events in 87.5% on ipamorelin versus 94.8% on placebo, in a post-surgical population; causality for individual events is not established in either source.
  • Immunogenicity and impurity concerns [8]
    FDA states compounded ipamorelin acetate may pose a risk of immunogenicity for certain routes because of aggregation or peptide-related impurities, and that its unnatural amino acids complicate characterisation.

04What is unknown

  • No published human pharmacokinetic or safety data for subcutaneous use were identified in this review (published human studies used intravenous infusion); FDA states it has not identified safety-related information for certain other injectable routes
  • No human data on repeated exposure beyond about a week; no long-term safety data
  • Results of the larger Phase 2 ileus trial (NCT01280344, 320 enrolled) have not been posted or published
  • Whether it increases body fat in humans, as it did in mice, is unknown
  • Product identity: N-terminally glycine-extended ipamorelin (Gly-ipamorelin) has been identified in black-market growth-promoting products, so what a vial sold as ipamorelin contains is uncertain
  • Regulatory status in the UK, Australia, Japan and China was not verified from regulator sources for this record

05Product quality

No independent purity results have been published for this compound yet. The purity programme will publish full methods and vendor-named results, passes and failures, once its protocol has had legal review.

06Citations

  1. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients (2014). doi:10.1007/s00384-014-2030-8
  2. Efficacy of Ipamorelin, a Novel Ghrelin Mimetic, in a Rodent Model of Postoperative Ileus (2009). doi:10.1124/jpet.108.149211
  3. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats (1999). doi:10.1054/ghir.1999.9998
  4. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats (2000). doi:10.1677/joe.0.1650569
  5. Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin, a Growth Hormone Releasing Peptide, in Human Volunteers (1999). doi:10.1023/a:1018955126402
  6. Growth Hormone (GH)-Independent Stimulation of Adiposity by GH Secretagogues (2001). doi:10.1006/bbrc.2000.4065
  7. Analysis of new growth promoting black market products (2018). doi:10.1016/j.ghir.2018.05.001
  8. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks

Every DOI is resolved against Crossref and every NCT number against ClinicalTrials.gov, title for title, before publication. Regulatory sources are cited inline above with a verbatim quote and retrieval date.

07Mechanism

Ipamorelin is an agonist at the growth hormone secretagogue (ghrelin) receptor; it released growth hormone in rats and swine, and in swine it did not raise ACTH or cortisol above levels seen with GHRH.

Mechanism is placed last on purpose: a plausible mechanism is not evidence that a compound works in people.

Reviewed by OSMF research team (AI-assisted, source-verified) on 2026-10-10. Found an error? It goes in the corrections log: report it.