Peptide dossier, updated Nov 1, 2026
Ipamorelin
A synthetic peptide that stimulates growth hormone release. Papers call it a growth hormone secretagogue and a ghrelin mimetic. It has no approved use. It was tested in two company-sponsored phase 2 trials for postoperative ileus. FDA lists it among compounding substances it flags for safety risk. This page lays out what each source actually says.
See all 11 verified records for Ipamorelin on the Records page
In plain terms
Approved for: Nothing. FDA has not approved ipamorelin for any use, and we found no approved drug that contains it.
What it is: A synthetic peptide that signals the pituitary gland to release growth hormone. Published papers describe it as a ghrelin-receptor agonist, meaning it acts on the same receptor as the hunger hormone ghrelin.
What it is said to do, and by whom:
- The sponsor, Helsinn: ran two phase 2 trials of intravenous ipamorelin to speed bowel recovery after abdominal surgery. The one published report found no significant difference from placebo on its main measure.
- Researchers: a 1999 study in healthy men reported that ipamorelin triggered growth hormone release at every dose tested. A 2001 rat study reported it counteracted a steroid-induced drop in bone formation.
- Sellers: FDA’s 2026 warning letters quote websites selling it in “research” blends with another peptide, and say those products are unapproved drugs. We did not collect the sellers’ own claims beyond what the letters quote.
How strong the evidence is: Thin. The two human efficacy trials were in postoperative ileus, not the uses sellers describe, and one has no published report that we found. FDA says a published study reported serious adverse events including death with intravenous use.
Human studies
ClinicalTrials.gov lists two ipamorelin studies as of Nov 1, 2026, both sponsored by Helsinn. A third record that matched the search, an observational study of combined therapies in combat veterans (NCT07717866), is left out. We opened it: its listed interventions are ibogaine with magnesium, 5-MeO-DMT, magnetic e-resonance therapy and “physiological supplementation”, and none names ipamorelin.
| Registry | Study | Status | What the record says |
|---|---|---|---|
| NCT00672074 | Phase 2, ipamorelin for postoperative ileus | Completed, Apr 2008 to Dec 2009 | 117 enrolled. Published in 2014: ipamorelin was well tolerated, and median time to the first tolerated solid meal was 25.3 hours versus 32.6 on placebo (p = 0.15). The authors report no significant differences in the key and secondary efficacy analyses. |
| NCT01280344 | Phase 2, ipamorelin versus placebo for recovery of gastrointestinal function | Completed, Apr 2011 to May 2014 | 320 enrolled. No results posted on the registry. We did not find a published report. |
Registry entries are written by sponsors and are not reviewed for scientific merit. A registered study is not a result.
FDA review
FDA’s safety-risk page (content current Apr 22, 2026) is the one FDA review document on ipamorelin that we read.
What the page says
- It lists ipamorelin acetate in the table of substances in category 2 under the 503B interim policy, added Sep 29, 2023. It says the substance also appears in the table of nominated-but-withdrawn substances.
- It says compounded drugs containing it may pose risk for immunogenicity for certain routes, because of aggregation or peptide-related impurities, and that it contains unnatural amino acids, which add to the complexity of characterization.
- It says a published study identified serious adverse events including death when ipamorelin was given intravenously to improve gastric motility. It says FDA has not identified safety information for certain other injectable routes, so it lacks sufficient information to know whether the drug would cause harm by those routes.
What we did not find
- The page does not name the study with the deaths. We did not confirm whether it is the 2014 trial above, whose abstract reports adverse events in both arms and does not mention deaths.
- We found no FDA briefing document, advisory committee review or press release specific to ipamorelin.
Published research
PubMed returns 51 results for ipamorelin in the title or abstract as of Nov 1, 2026. Most are animal studies, doping-detection work and 2026 reviews of peptide use.
What the papers show
- Postoperative ileus, 2014. The phase 2 trial above. Int J Colorectal Dis PubMed
- Healthy men, 1999. Eight men per dose at five intravenous dose levels. Terminal half-life about 2 hours, with growth hormone released at every dose. Pharm Res PubMed
- Rats, 2001. Ipamorelin counteracted a glucocorticoid-induced decrease in bone formation. Growth Horm IGF Res PubMed
- Reviews, 2026. Several narrative reviews discuss ipamorelin among performance and sports-medicine peptides. We read titles only. Front Endocrinol PubMed
Read with care
- A hormone rise in healthy volunteers is a laboratory measure, not evidence of a health benefit.
- The bone and other effects come from rats. We found no human study of ipamorelin for bone, muscle, fat or aging.
- We read abstracts only, not full text, funding or author disclosures.
FDA warning letters
We found three FDA warning letters that name ipamorelin: one to a compounding pharmacy and two to online sellers. This rests on web searches, not a full pull of FDA’s database.
| Recipient | Date | Letter | What it says |
|---|---|---|---|
| NuScience Peptides LLC, an online seller | Aug 24, 2026 | Warning letter 733652 | FDA lists a “Tesamorelin Ipamorelin Blend” among products it treats as unapproved new drugs, alongside retatrutide and others. It quotes the seller’s page saying research “has indicated” ipamorelin can counteract glucocorticoid-induced reductions in bone formation. |
| Royal Peptides LLC, an online seller | Aug 24, 2026 | Warning letter 734884 | FDA cites a “Tesamorelin and Ipamorelin” blend sold as a research product, and treats it as an unapproved new drug. |
| Tailor Made Compounding LLC, a compounding pharmacy | Apr 1, 2020 | Warning letter 594743 | FDA says an inspection found the firm compounding with a list of 22 bulk substances that includes Ipamorelin, and that drugs made from them were not eligible for the section 503A exemptions because none is covered by a USP or NF monograph, is a component of an FDA-approved drug, or appears on the 503A bulks list. We read the letter text. |
A warning letter is FDA’s statement about one firm’s conduct on one date. It is not a finding about the substance. FDA’s list of letters cannot be searched by peptide, so other letters could exist that we did not find.
Timeline
Newest first. Every entry links to the document it comes from.
- Government or registry record
- Journal
- Oct 30, 2026RegulatoryHHS publishes draft policy pausing enforcement on six peptides; Ipamorelin is not one of them
The draft policy’s appendix names six peptides: BPC-157, epitalon, KPV, MOTS-c, Semax and TB-500. The policy is a draft and not FDA approval. We read the appendix through a text extraction.
- Aug 24, 2026EnforcementFDA warning letters to two online sellers cite tesamorelin-ipamorelin blends
Both letters treat the blends as unapproved new drugs despite “research” labeling.
- July 23–24, 2026RegulatoryFDA advisory committee meets on seven peptides; Ipamorelin is not among them
The committee recommended six of the seven, all nonbinding. FDA’s notice of the meeting does not list Ipamorelin.
- Apr 22, 2026RegulatoryFDA’s safety-risk page lists Ipamorelin
FDA lists it as a substance that may present significant safety risks and cites a published study with serious adverse events including death after intravenous use.
- Jan 1, 2026Anti-dopingWADA’s 2026 Prohibited List names ipamorelin in S2.2.4
The list names it among growth hormone secretagogues. We read a copy hosted by an athletics federation, not WADA’s own file.
- Sep 29, 2023RegulatoryFDA places ipamorelin acetate in category 2 under the 503B interim policy
Date added, per FDA’s safety-risk page.
- Apr 1, 2020EnforcementFDA warning letter to a compounding pharmacy names Ipamorelin among 22 substances
The letter says drugs the firm compounded from these bulk substances were not eligible for the 503A exemptions.
- 2014LiteraturePhase 2 trial in postoperative ileus reports no significant difference from placebo
117 patients. Published in Int J Colorectal Dis.
Still not covered
Left off rather than guessed:
- HHS policy: we read the draft policy appendix through a text extraction, not as the original PDF layout. It names six covered peptides and not ipamorelin.
- FDA review: we found no FDA briefing document or advisory committee evaluation for ipamorelin. FDA’s notice for the July meeting does not name it, so the safety-risk page entry is the only FDA statement on it that we read.
- The second Helsinn trial: 320 enrolled, completed in 2014, no results on the registry. We searched PubMed and Europe PMC and found no publication.
- The study FDA cites for deaths: not identified by FDA’s page. The 2014 postoperative ileus trial (intravenous, 0.03 mg/kg twice daily) is the only published human intravenous ipamorelin study we found. Its abstract says the drug was well tolerated and does not mention deaths. Its full text is not open access, so we could not check whether it reports any, or whether it is the study FDA means.
- Drugs@FDA: we searched openFDA’s copy of the Drugs@FDA data by active ingredient and found no application. FDA’s own Drugs@FDA site could not be searched from our tools.
- Patents and SEC filings: not researched for this dossier.
- Seller claims and independent lab reports: how gray-market product is marketed versus what testing finds. We have not collected testing data.
- Unread items: full text of most papers; EU and other non-US regulators and registries; WADA lists for years other than 2026; FDA warning letters beyond those listed, which rest on web searches.