Compound monograph
Ipamorelin
Also known as: NNC 26-0161
§1 Definition
Ipamorelin is a synthetic pentapeptide that selectively stimulates growth hormone release via the ghrelin receptor, without significantly raising cortisol, ACTH, or prolactin — a selectivity profile distinct from earlier growth-hormone-releasing peptides. Not FDA-approved for any use. It reached Phase 2 human trials for postoperative ileus, which did not meet its primary endpoint, and development was discontinued.
Educational purposes only, not medical advice. Dosing figures below are documented ranges from cited literature, not a recommendation for any individual. Consult a qualified provider before administering anything.
§2 Evidence tier and regulatory status
Evidence tier
2 — Late-phase trials
Not yet FDA-approved, but in Phase 2 or Phase 3 clinical trials with published human data.
Not FDA-approved for any indication. Originally developed by Novo Nordisk, later licensed to Helsinn Therapeutics, which sponsored a Phase 2 randomized controlled trial for postoperative ileus (ClinicalTrials.gov NCT00672074, completed December 2009) that did not meet its primary endpoint; development was discontinued afterward. No evidence was found in this research pass of an FDA 503A bulk-substance nomination or warning specific to ipamorelin.
§3 Documented dosing
No standardized human therapeutic dose was ever established, since development was discontinued before approval. The Phase 1 study below used IV infusion doses of 4.21-140.45 nmol/kg — a research dose-escalation range, not a recommended dose — so it is not presented as a documented range here.
§4 Reconstitution math
No FDA-approved product exists, so no FDA-labeled reconstitution protocol exists either. General lyophilized-peptide reconstitution practice is commonly applied by research users, but this is not backed by a compound-specific clinical or regulatory source.
- Concentration
- 5000 mcg/mL
- Draw volume
- 0.05 mL
- Syringe units
- 5.0
- Doses per vial
- 40
§5 What the research shows
| Trial | Phase | n | Duration | Endpoint | Result | Source |
|---|---|---|---|---|---|---|
| Phase 1 PK/PD study | Phase 1 | 40 | Single-dose IV infusion | Pharmacokinetic-pharmacodynamic characterization in healthy male volunteers | 8 healthy male subjects across 5 dose levels (4.21-140.45 nmol/kg). Dose-proportional pharmacokinetics; terminal half-life approximately 2 hours; GH release peaked 0.67 hours post-dose, with no significant ACTH, cortisol, or prolactin elevation across all doses tested. | [1] |
| Postoperative ileus trial | Phase 2 | 117 | Postoperative period following bowel resection | Time to GI recovery / first tolerated meal after bowel resection | Did not meet its primary endpoint — no significant difference vs placebo in time to first meal intake or measurable colonic function recovery. Development was discontinued following this result. | [2], [3] |
§6 Safety and reported adverse effects
No published adverse-effect data located.
No specific adverse-event incidence rates were located in this research pass. The Phase 2 trial's available summary emphasizes the missed efficacy endpoint over a detailed adverse-event table.
Contraindications
- No published data located — no FDA label or completed approval program exists for ipamorelin.
Known interactions
- No published data located — no FDA label or completed approval program exists for ipamorelin.
§7 Storage and handling
- Lyophilized
- No published data located.
- Reconstituted
- No published data located.
§8 Sourcing considerations
- Since ipamorelin is not FDA-approved for any use and is sold only as a research chemical, verify the seller provides a Certificate of Analysis from an independent, named third-party lab.
- Check for batch-specific testing rather than a generic product-line certificate, since purity and identity can vary between batches.
- Ipamorelin is often sold combined with CJC-1295 — verify each peptide's identity and concentration separately, since they are chemically distinct compounds with different evidence bases (see the CJC-1295 monograph).
§9 FAQ
What is ipamorelin?
A synthetic pentapeptide that selectively stimulates growth hormone release via the ghrelin receptor, notable for not significantly raising cortisol, ACTH, or prolactin — see the 1998 selectivity study cited in the sources below.
Is ipamorelin FDA approved?
No. It was in pharmaceutical development for postoperative ileus but did not meet its primary endpoint in a Phase 2 trial, and development was discontinued. It is now sold only as a research chemical.
Has ipamorelin been tested in humans?
Yes — a Phase 1 pharmacokinetic study in 8 healthy male volunteers, and a Phase 2 randomized controlled trial (n=117) for postoperative ileus that did not meet its primary endpoint.
Why was ipamorelin development discontinued?
Its sponsor (Helsinn Therapeutics) ran a Phase 2 trial for postoperative ileus that failed to show a significant difference from placebo in time to GI recovery, and development did not continue past that result.
Is ipamorelin the same as CJC-1295?
No. They are chemically distinct peptides with different mechanisms — ipamorelin is a ghrelin-receptor agonist, while CJC-1295 is a GHRH analog — commonly sold together but not the same compound.
What is ipamorelin's half-life?
Approximately 2 hours, based on a human single-dose IV infusion pharmacokinetic study.
Does ipamorelin raise cortisol?
The 1998 pharmacology study that characterized it found no significant elevation of cortisol, ACTH, or prolactin at any dose tested, distinguishing it from earlier growth hormone secretagogues.
§10 Sources
- [1] Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin, a Growth Hormone Releasing Peptide, in Human Volunteers. Pharmaceutical Research, 1999. Peer-reviewed. https://link.springer.com/article/10.1023/A:1018955126402
- [2] Prospective, Randomized, Controlled, Proof-of-Concept Study of the Ghrelin Mimetic Ipamorelin for the Management of Postoperative Ileus in Bowel Resection Patients. International Journal of Colorectal Disease, 2014. Peer-reviewed. https://link.springer.com/article/10.1007/s00384-014-2030-8
- [3] Safety and Efficacy of Ipamorelin for Management of Post-Operative Ileus. ClinicalTrials.gov, 2009. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT00672074
- [4] Ipamorelin, the First Selective Growth Hormone Secretagogue. European Journal of Endocrinology, 1998. Peer-reviewed. https://pubmed.ncbi.nlm.nih.gov/9849822/