Ipamorelin: two trials, and the one that mattered missed

What this comes down to

• The two reports found by our September 2026 search describe: a 1999 pharmacokinetic study in volunteers and a 2014 phase 2 trial in bowel-resection patients.
• The phase 2 missed. Median time to a first tolerated meal was 25.3 hours on ipamorelin against 32.6 on placebo, which the trial reports as not statistically significant.
• The FDA places ipamorelin acetate in category 2 under its 503B interim policy, nominated September 29, 2023, and separately lists it among the withdrawn nominations.
• The FDA links the 2014 intravenous ipamorelin study and says it identified serious adverse events including death. That statement does not establish that the drug caused a death.

The trial a drug company actually ran

Ipamorelin is a ghrelin-receptor agonist, and ghrelin stimulation speeds up the gut. That is a testable idea, and somebody tested it. A multicenter, double-blind, placebo-controlled phase 2 study enrolled 117 adults having open or laparoscopic bowel resection, of whom 114 made up the safety and modified intent-to-treat populations, and gave intravenous ipamorelin at 0.03 mg/kg twice daily from postoperative day one until discharge or day seven^[1].

The key endpoint was time from the first dose to tolerating a standard solid meal. Median 25.3 hours on ipamorelin, 32.6 on placebo, and the paper reports that as not significant. Treatment-emergent adverse events occurred in 87.5% of the ipamorelin group and 94.8% of the placebo group. The authors' conclusion is that the dose was well tolerated and that there were no significant differences between ipamorelin and placebo on the key or secondary efficacy endpoints. It is one of two reports returned by our September 2026 randomized-trial PubMed search^[3]; the other is a 1999 pharmacokinetic study in volunteers. A 2026 structured review of injectable peptides in sports medicine puts ipamorelin with the rest of the growth-hormone-axis secretagogues: investigational, uncertain safety, product quality concerns^[4].

The whole literature, counted. A PubMed search finds 2 results; the same search for semaglutide finds 316.

The one placement that is not a withdrawn nomination

Most peptides on these menus reach the FDA's compounding page as nominations somebody later pulled. Ipamorelin acetate is on that page twice: once in the live category 2 table, under the 503B interim policy, with a nomination date of September 29, 2023, and again in the withdrawn table with a note saying it also appears above^[2]. Category 2 is the bucket for substances where the agency has identified significant safety risks and declines to extend the enforcement grace period it gives category 1.

“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. Ipamorelin acetate also contains unnatural amino acids, which add to the complexity of peptide characterization. A study published in literature identified serious adverse events including death when ipamorelin was administered intravenously for improving gastric motility.”

^[2]

How it is actually sold

Across the 387 sellers we have read, one priced line names ipamorelin, and it is a blend — ipamorelin with CJC-1295, sold as one protocol at one price by Live Vital. Blending is the norm for this pair, and it has a consequence worth stating plainly: neither peptide was studied that way. The 2014 trial gave ipamorelin alone, intravenously, in a hospital. The CJC-1295 trial gave CJC-1295 alone, subcutaneously, to healthy adults. Our September 2026 PubMed search found no randomized-trial reports of the combination.

Both are also compounded preparations, which means the questions about the vial apply on top of the questions about the molecule — what a certificate of analysis does and does not cover is the place to start. And the FDA's own text flags the specific reason ipamorelin is hard to characterize: it contains unnatural amino acids.

Questions people actually ask