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Research review · Sources checked October 17–29, 2026

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Ipamorelin: what the research shows

Ipamorelin is a five-amino-acid peptide that releases growth hormone through the ghrelin receptor. Novo Nordisk designed it in the 1990s. It is not an FDA-approved drug, its one published patient trial failed, and FDA’s compounding advisers voted against it in 2024.[1][3][8][5]

Preclinical profile

Novo Nordisk researchers described ipamorelin in 1998 as the first selective growth hormone secretagogue. In rats and pigs it released growth hormone with potency similar to GHRP-6, and in pigs it didn’t raise ACTH or cortisol beyond the levels seen with GHRH, even at doses more than 200-fold above the effective dose.[1] These are animal findings.

Human studies

Every human study gave ipamorelin by vein. In healthy men, a 15-minute infusion produced a single growth hormone peak at about 40 minutes, with a half-life of about two hours; FDA notes the lowest dose (about 3 mcg/kg) produced negligible growth hormone.[2][4] In a phase 2 trial after bowel surgery (NCT00672074), 0.03 mg/kg twice daily didn’t significantly beat placebo among 114 patients (median time to first tolerated meal 25.3 vs 32.6 hours, p = 0.15). FDA’s review notes more low potassium and high blood sugar on ipamorelin and two deaths whose relation to the drug is unclear.[3][4] A larger 320-patient dose-finding trial (NCT01280344) finished in May 2014 with no results posted and no publication we could find; FDA says development was discontinued.[7][4] FDA found no human data for injection under the skin, the way it is sold.[4]

Regulatory status

No FDA-approved drug contains ipamorelin.[8] In October 2024 FDA’s compounding advisers voted 0 to 12, with 1 abstention, against adding either form to the 503A list, citing “a lack of information supporting safety and efficacy.”[5] Ipamorelin acetate is still in category 2 under FDA’s 503B (outsourcing facility) policy, added September 29, 2023, and also appears among withdrawn nominations.[6] It is not on the agenda for FDA’s 2026–2027 peptide advisory meetings.[10] An FDA peptide compounding policy cleared White House review on October 27, 2026; the version HHS made public on October 28 lists six peptides, and ipamorelin is not among them.[9]

Update, October 29, 2026: A coroner in Victoria, Australia, found that the March 2025 death of actor Richard Norton, 75, was “triggered by his injection of the peptide CJC1295/Ipamorelin,” which “caused an anaphylactic reaction which in turn led to cardiac arrest.” The finding says he had taken more than the prescribed dose, lists asthma and a heart condition as contributing, and notes the peptides could not be detected in post-mortem testing. The coroner recommended that Australia’s TGA consider prohibiting such peptides outside clinical trials.[11] One case can’t show how often this happens; our teardown walks through the finding.

What is not known

There are no positive efficacy trials in people, no data for the under-the-skin route, no long-term safety data, and no trial of ipamorelin combined with CJC-1295.[4] For the dose comparison and the full paper trail, see our teardown.

References

  1. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. PMID 9849822 (Novo Nordisk; rats and swine; no ACTH or cortisol rise beyond GHRH levels “even at doses more than 200-fold higher than the ED50 for GH release”). https://pubmed.ncbi.nlm.nih.gov/9849822/. Checked October 17, 2026.
  2. Gobburu JV, Agersø H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412-1416. PMID 10496658 (healthy men; 15-minute IV infusions of 4.21 to 140.45 nmol/kg; half-life about 2 hours; single GH peak at 0.67 hours). https://pubmed.ncbi.nlm.nih.gov/10496658/. Checked October 17, 2026.
  3. Beck DE, Sweeney WB, McCarter MD; Ipamorelin 201 Study Group. 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. 2014;29(12):1527-1534. PMID 25331030 (114 analyzed; 0.03 mg/kg IV twice daily; median time to first tolerated meal 25.3 vs 32.6 hours, p = 0.15). https://pubmed.ncbi.nlm.nih.gov/25331030/. Checked October 17, 2026.
  4. U.S. Food and Drug Administration. Pharmacy Compounding Advisory Committee briefing document: ipamorelin-related bulk drug substances (ipamorelin free base and acetate), for the October 29, 2024 meeting. Molecular weight 711.85 g/mol; Gobburu et al. 1999 summary (“Five groups with 6 healthy male subjects per group … over a 15-minute IV infusion and 2 subjects per group received placebo”; “The lowest dose of 4.21 nmol/kg group and placebo groups were not included in the PK/PD analysis due to negligible GH levels”); “FDA did not identify PK or PD information for the proposed SC route”; Beck et al. 2014 adverse events and two deaths (“it is unclear whether the two deaths were related to ipamorelin”); development discontinued (citing Ishida et al. 2020); FAERS through September 30, 2023 (two non-serious reports); M-CERSI report of a “trending” combination with CJC-1295. https://www.fda.gov/media/182088/download. Checked October 17, 2026.
  5. U.S. Food and Drug Administration. Summary minutes of the Pharmacy Compounding Advisory Committee, October 29, 2024 (approved January 15, 2025). Ipamorelin free base and ipamorelin acetate, uses reviewed growth hormone deficiency and postoperative ileus: 0 yes / 12 no / 1 abstain each (“lack of information supporting safety and efficacy”; “the high frequency of a drug being prescribed does not necessarily mean the drug is safe and effective”). Open public hearing speakers for ipamorelin: James Lavalle and Lee Rosebush (Farmakeio and Evexias). https://www.fda.gov/media/185412/download. Meeting page: https://www.fda.gov/advisory-committees/advisory-committee-calendar/october-29-2024-meeting-pharmacy-compounding-advisory-committee-10292024. Checked October 17, 2026.
  6. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (Category 2). Content current as of April 22, 2026. Ipamorelin acetate in the category 2 table (503B, added September 29, 2023: “A study published in literature identified serious adverse events including death when ipamorelin was administered intravenously for improving gastric motility”) and in the table of nominations withdrawn; CJC-1295 in the withdrawn table (“FDA has identified serious adverse events associated with CJC-1295 including increased heart rate and systemic vasodilatory reaction. Available clinical data are limited.”). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks. Checked October 17, 2026.
  7. ClinicalTrials.gov. NCT00672074 (Helsinn, ipamorelin in postoperative ileus, phase 2, completed) https://clinicaltrials.gov/study/NCT00672074; NCT01280344 (Helsinn, phase 2 dose-finding study of ipamorelin 0.03 mg/kg twice daily, 0.06 mg/kg twice daily or 0.06 mg/kg three times daily versus placebo after bowel resection; 320 enrolled; started April 2011; completed May 2014; no results posted) https://clinicaltrials.gov/study/NCT01280344. Checked October 17, 2026.
  8. U.S. Food and Drug Administration. Drugs@FDA via the openFDA drugsfda endpoint: application 022505, EGRIFTA (tesamorelin), Theratechnologies; original approval November 10, 2010. Searches for ipamorelin and CJC-1295 returned no approved application. Sermorelin was approved as Geref (NDA 019863 and 020443) until FDA withdrew both approvals in 2009 at the maker’s request; FDA later determined the products were not withdrawn for reasons of safety or effectiveness (78 FR 14095, March 4, 2013). https://api.fda.gov/drug/drugsfda.json?search=openfda.generic_name:%22tesamorelin%22. Checked October 17, 2026.
  9. Office of Information and Regulatory Affairs (OMB). Pending EO 12866 Regulatory Review: Interim Access Policy for Compounding Using Certain Peptides, RIN 0910-ZD94, received 10/14/2026, stage: Notice; no conclusion listed when checked at about 4 AM ET. https://www.reginfo.gov/public/do/eoDetails?rrid=1568964. Checked October 17, 2026. Update: OIRA’s report of reviews completed in the last 30 days, run October 28, 2026, lists this review as completed 10/27/2026, “Consistent with Change” (https://www.reginfo.gov/public/do/XMLViewFileAction?f=EO_RULE_COMPLETED_30_DAYS.xml). On October 28, 2026, HHS filed a notice of availability for public inspection, “Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances” (FR Doc. 2026-22192, RIN 0910-ZD94, docket HHS-OASH-2026-0496; filed 11:15 AM ET; published in the Federal Register October 30, 2026, 91 FR 68526; the notice says comments can be submitted via regulations.gov until 2 weeks after publication, and regulations.gov lists the comment deadline as November 13, 2026, 11:59 PM ET) (https://www.federalregister.gov/documents/2026/10/30/2026-22192/enforcement-discretion-policy-regarding-503a-compounding-using-certain-peptide-bulk-drug-substances). The policy document’s Appendix A lists BPC-157, epitalon, KPV, MOTS-c, semax and TB-500 (https://www.hhs.gov/sites/default/files/hhs-503a-peptide-enforcement-discretion-policy-appendix-b.pdf). Checked October 28, 2026, about noon ET.
  10. U.S. Food and Drug Administration. Pharmacy Compounding Advisory Committee, July 23–24, 2026: introduction to briefing packages (substances: BPC-157, KPV, TB-500, MOTS-c, semax, epitalon and emideltide/DSIP) https://www.fda.gov/media/193342/download; and Meeting of the Pharmacy Compounding Advisory Committee (“before the end of February 2027”; agenda: LL-37, GHK-Cu, dihexa acetate, Melanotan II, PEG-MGF), content current as of April 15, 2026 https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee. Checked October 17, 2026.
  11. Coroners Court of Victoria. Finding into death without inquest (Form 38): Richard John Norton, COR 2025 001710. Coroner David Ryan, signed October 28, 2026 (cause of death 1(a) complications of an out of hospital cardiac arrest, 1(b) anaphylaxis; 2 asthma, hypertrophic cardiomyopathy; recommendation to the TGA under section 72(2)). https://www.coronerscourt.vic.gov.au/sites/default/files/COR%202025%20001710%20Form%2038%20-%20Finding%20into%20Death%20without%20Inquest%5FSigned.pdf. Read in full October 29, 2026.

This page summarizes published research and regulatory documents. It is not medical advice and does not recommend using, sourcing, or dosing any of these substances.