Research
Ipamorelin human and clinical evidence
Every human study and registered trial of ipamorelin, with designs, populations, endpoints and results as reported. Two trials; one never published.
By the Ipamorelin Research editorial team · Last reviewed · Scientific review: pending
Short answer
There are 2 registered clinical trials of ipamorelin, both phase 2, both complete. Between them they randomised 437 people, and results exist in the public record for 117 of them. The one reported trial tested recovery of gut function after bowel surgery and found no significant difference from placebo. Three human studies are indexed in PubMed, none of which measured muscle, fat, recovery or ageing.
Every registered trial
A search of ClinicalTrials.gov for ipamorelin returns three records [ClinicalTrials.gov]. All three are listed below in full, including the one that is not actually a study of ipamorelin and the one that has never reported. None has posted results to the registry.
- Registered trials of ipamorelin
- 2
- both phase 2, both completed
- Published with results
- 1
- one trial
- Completed but never reported
- 1
- the larger of the two
- Participants randomised
- 437
- 117 of them in the reported trial
- Published
Phase 2 · Completed · 2008-04 to 2009-12
Postoperative ileus, proof of concept
A Phase II, Double-Blind, Placebo-Controlled, Multiple-Dose Study to Evaluate the Safety and Efficacy of Ipamorelin Compared to Placebo for the Management of Post-Operative Ileus
- Sponsor
- Helsinn Therapeutics (U.S.), Inc
- Enrolment
- 117 participants at 19 sites
- Allocation
- Randomised, parallel assignment
- Masking
- Quadruple (participant, care provider, investigator, outcomes assessor)
- Population
- Adults aged 18 and over undergoing small or large bowel resection, open or laparoscopic
- Arms
- Ipamorelin 0.03 mg/kg intravenously twice daily · Matching placebo
- Primary endpoint
- Time from first dose of study drug to tolerance of a standardised solid meal(a clinical outcome, not an endocrine measurement)
Reported results for NCT00672074 Endpoint Ipamorelin Placebo As reported Median time to first tolerated solid meal 25.3 hours 32.6 hours P = 0.15, not statistically significant Any treatment-emergent adverse event 87.5% of subjects 94.8% of subjects Reported without a significance test What it found
The published report states that there were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses, and that ipamorelin was well tolerated. The numerical difference in time to first tolerated meal favoured ipamorelin but did not reach statistical significance.
Safety as reported
The publication reports overall adverse-event rates and describes the drug as well tolerated. FDA’s 2024 review of this trial reported serious adverse events in 10 ipamorelin subjects (17.9%) and 9 placebo subjects (15.5%), including two fatal serious adverse events in ipamorelin-treated subjects who had undergone bowel resection for colon cancer and developed anastomotic leak. FDA stated it is unclear whether those deaths were related to ipamorelin, and also noted higher rates of hypokalemia, insomnia and hyperglycemia in the ipamorelin group.
Limitations
The authors describe the study as small, with a broad range of underlying conditions. No registry results have been posted. The endpoint is postoperative gastrointestinal recovery; the trial measured nothing about body composition, muscle, athletic recovery or ageing.
NCT00672074 on ClinicalTrials.gov · Publication, PubMed 25331030 · Registry record retrieved 2026-11-11
- No results in the public record
Phase 2 · Completed · 2011-04 to 2014-05
Dose-finding, bowel resection
Phase II Double-Blind Placebo-Controlled Dose Finding Study to Evaluate Safety/Efficacy of Ipamorelin Compared to Placebo for Recovery of Gastrointestinal Function in Patients Following Small or Large Bowel Resection with Primary Anastomosis
- Sponsor
- Helsinn Therapeutics (U.S.), Inc
- Enrolment
- 320 participants at 45 sites
- Allocation
- Randomised, parallel assignment
- Masking
- Quadruple (participant, care provider, investigator, outcomes assessor)
- Population
- Adults aged 18 and over following small or large bowel resection with primary anastomosis
- Arms
- Ipamorelin 0.03 mg/kg twice daily · Ipamorelin 0.06 mg/kg twice daily · Ipamorelin 0.06 mg/kg three times daily · Matching placebo three times daily
- Primary endpoint
- Recovery of gastrointestinal function, up to 10 days(a clinical outcome, not an endocrine measurement)
What it found
No results have been posted to the registry and no publication of this trial was found in the PubMed search behind this database. This is the largest registered ipamorelin trial, at nearly three times the enrolment of the published one, and what it found is not in the public record.
Safety as reported
Adverse events were a listed secondary outcome measure. No safety results are available from any public source.
Limitations
Nothing can be said about what this trial found. Its absence matters: any summary of ipamorelin’s human evidence that cites only the published trial is describing the smaller of the two completed phase 2 studies.
NCT01280344 on ClinicalTrials.gov · Registry record retrieved 2026-11-11
- No results in the public record
Not applicable (observational) · Active, not recruiting · 2022-08-01 to 2026-11
Trifecta observational cohort
Trifecta Research Study: An Observational Study Evaluating the Impact of Ibogaine-Magnesium, 5-MeO-DMT, Magnetic e-Resonance Therapy, and Physiological Supplementation in Special Operations Forces Combat Veterans
Not a study of ipamorelin. Listed so the registry search is reproducible.
- Sponsor
- Axial Therapeutic Research
- Enrolment
- 52 participants at 1 site
- Allocation
- Observational prospective cohort
- Masking
- None
- Population
- Special operations forces combat veterans
- Arms
- Intervention sequence 1 · Intervention sequence 2
- Primary endpoint
- PTSD Checklist for DSM-5 and cognitive measures, to 12 months
What it found
This record is retrieved by a registry search for ipamorelin but is not a study of ipamorelin. Its interventions are ibogaine, 5-MeO-DMT, magnetic e-resonance therapy and a multi-component programme the protocol calls "Physiological Supplementation". It is listed here only so the registry search is reproducible, and it contributes no ipamorelin evidence.
Safety as reported
Not applicable to ipamorelin.
Limitations
Observational, single site, no control group, multiple simultaneous interventions. No ipamorelin-specific conclusion could be drawn from it even when it reports.
NCT07717866 on ClinicalTrials.gov · Registry record retrieved 2026-11-11
Endocrine findings and clinical outcomes are different things
These two categories are kept separate throughout this site, because conflating them is the most common error made about this compound.
Endocrine or pharmacodynamic
What the drug does to a hormone level
The 1999 study measured growth hormone concentrations in 40 healthy men and characterised a single pulse peaking at 0.67 hours [Gobburu 1999]. This is a real, reproducible measurement. It says nothing about whether anything useful follows from that pulse.
Clinical outcome
Whether patients were better off
The 2014 trial measured time to tolerate a solid meal after bowel surgery — something that matters to a patient. The result was 25.3 hours against 32.6 hours for placebo, P = 0.15, with no significant differences in the key and secondary analyses [Beck 2014].
Research administration is not validated dosing
The doses in these trials were chosen by a sponsor for a hospital study with intravenous infusion, monitoring and a defined surgical population, over no more than seven days. They were tested in two trials, one of which was null and one of which never reported, and no dose has ever been shown to be effective for anything. There is no validated dose of ipamorelin for any purpose, and this site publishes no dosing, administration or self-use guidance of any kind. The pharmacokinetics measured in healthy volunteers are reported on the molecular data page as research findings, not as instructions.
The three human records in PubMed
Beyond the trial registry, three indexed publications involve humans receiving ipamorelin. The third is a single-subject anti-doping excretion study, included because it establishes that intranasal administration has occurred under study conditions, though it measured no effect and no safety endpoint[Semenistaya 2015].
| Study | Model and route | What was measured | Limitations | Grade |
|---|---|---|---|---|
| Semenistaya 2015 Drug Test Anal Pharmacokinetics · Analytical and anti-doping methods | HumanIntranasal Healthy volunteers, single intranasal administration, urine collected for 2 days Among severaln = One volunteer per compound | The study administered GHRP-1, GHRP-2, GHRP-6, hexarelin and ipamorelin intranasally, one volunteer each, and identified urinary metabolites. Hexarelin and ipamorelin were reported to metabolise intensively and to be excreted as parent compound together with metabolites; ipamorelin (1-4) free acid was detected in urine after the parent substance had cleared. | One volunteer per compound, so this establishes that humans have received intranasal ipamorelin under study conditions but supports no conclusion about effect or safety. The purpose is anti-doping method development. | Evidence grade B |
| Beck 2014 Int J Colorectal Dis Gastrointestinal motility · Safety reporting | HumanIntravenous Adults undergoing small and large bowel resection by open or laparoscopic surgery, 19 sites Ipamorelin itselfn = 117 enrolled; 114 in the safety and modified intent-to-treat populations | The trial compared intravenous ipamorelin 0.03 mg/kg twice daily with placebo from postoperative day 1 to day 7 or hospital discharge. Median time to first tolerated meal was 25.3 hours with ipamorelin and 32.6 hours with placebo (P = 0.15). Any treatment-emergent adverse event occurred in 87.5% of the ipamorelin group and 94.8% of the placebo group. | The authors describe the trial as small, with patients drawn from a broad range of underlying conditions. It is a proof-of-concept study in postoperative recovery; it was not designed to measure body composition, athletic recovery or ageing, and it reports no such endpoints. | Evidence grade A |
| Gobburu 1999 Pharm Res Pharmacokinetics · Growth hormone secretion | HumanIntravenous Healthy male volunteers, 15-minute intravenous infusions Ipamorelin itselfn = 8 per dose level across 5 dose levels | The study measured pharmacokinetics and GH response after 15-minute infusions of 4.21, 14.02, 42.13, 84.27 and 140.45 nmol/kg. Pharmacokinetics were dose-proportional, with a terminal half-life of 2 hours, clearance of 0.078 L/h/kg and steady-state volume of distribution of 0.22 L/kg. GH release was a single episode peaking at 0.67 hours and declining exponentially to negligible concentrations at every dose. The concentration producing half-maximal GH stimulation was 214 nmol/L. | Healthy young men only; single infusions; the measured endpoint is hormone concentration, not any clinical outcome. PubMed indexes this record with the publication types "Clinical Trial" and "Randomized Controlled Trial", but the published abstract describes a dose-escalation design and does not describe randomisation or a placebo control, so it is graded here as a human study without a control group. | Evidence grade B |
How to read the safety numbers
The published trial and FDA's review of it describe the same data differently, and both descriptions are on the safety page, including the two deaths FDA reported and FDA's own statement that it is unclear whether they were related to ipamorelin[FDA briefing 2024].
References
- Beck DE, Sweeney WB, McCarter MD et al. (2014). Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. PubMed 25331030 · doi:10.1007/s00384-014-2030-8[Human, grade A]
- Gobburu JV, Agersø H, Jusko WJ et al. (1999). Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. PubMed 10496658 · doi:10.1023/a:1018955126402[Human, grade B]
- Semenistaya E, Zvereva I, Thomas A et al. (2015). Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin. Drug Test Anal. PubMed 25869809 · doi:10.1002/dta.1787[Human, grade B]
- ClinicalTrials.gov, U.S. National Library of Medicine (2008-04). A Phase II, Double-Blind, Placebo-Controlled, Multiple-Dose Study to Evaluate the Safety and Efficacy of Ipamorelin Compared to Placebo for the Management of Post-Operative Ileus (NCT00672074). Source[retrieved 2026-11-11]
- ClinicalTrials.gov, U.S. National Library of Medicine (2011-04). Phase II Double-Blind Placebo-Controlled Dose Finding Study to Evaluate Safety/Efficacy of Ipamorelin Compared to Placebo for Recovery of Gastrointestinal Function Following Bowel Resection (NCT01280344). Source[retrieved 2026-11-11]
- ClinicalTrials.gov, U.S. National Library of Medicine (2022-08-01). Trifecta Research Study (NCT07717866). Source[retrieved 2026-11-11]
- ClinicalTrials.gov, U.S. National Library of Medicine. ClinicalTrials.gov search: ipamorelin. Source[retrieved 2026-11-11]
- U.S. Food and Drug Administration (2024-10-29). FDA Briefing Document, Pharmacy Compounding Advisory Committee: Ipamorelin. Source[retrieved 2026-11-11]