What Does Ipamorelin Do? Human Results and Vial Tests
A 1999 study gave ipamorelin to 40 healthy men (PMID 10496658). It triggered GH release at all five research levels (PMID 10496658). The release peaked at 0.67 hours (PMID 10496658). Its terminal half-life was 2 hours (PMID 10496658). The study measured hormones, not muscle gain, recovery, sleep, or fat loss. Its accessible record gives no funding statement. Two of four authors worked for Novo Nordisk. These claims were checked 22 August 2026.
What did ipamorelin do in human studies?
Two published human studies answer different questions. One measured growth hormone in healthy men. The other tested recovery of gut function after bowel surgery.
Growth hormone release in 40 healthy men
Gobburu and colleagues studied 40 healthy men across rising research levels (PMID 10496658). Eight men took part at each of five levels (PMID 10496658). The peptide triggered GH release at every level. The release peaked at 0.67 hours. It then fell to a negligible level in every group (PMID 10496658).
The terminal half-life was 2 hours (PMID 10496658). The reported clearance was 0.078 L/h/kg (PMID 10496658). The volume at steady state was 0.22 L/kg (PMID 10496658). The model estimated 214 nmol/L for a half-maximal GH response. It estimated a top GH production rate of 694 mIU/L/h (PMID 10496658). Hormone responses varied more between men than the drug measures did.
The accessible abstract reports no adverse-event result. The study measured hormone levels after an infusion into a vein. It did not measure muscle gain, recovery, sleep, fat loss, or another clinical result.
Funding: The accessible journal page gives no funding statement. Two authors were affiliated with Novo Nordisk. Two authors were affiliated with the State University of New York at Buffalo. These facts and results were checked 22 August 2026.
A published trial in 117 bowel-surgery patients
The second paper reports a randomized, double-blind, placebo-controlled phase 2 trial (PMID 25331030; NCT00672074). It enrolled 117 hospital patients after small or large bowel surgery. The analysis included 114 patients (PMID 25331030). The peptide and placebo were given into a vein.
Median time to the first tolerated meal was 25.3 hours with the peptide and 32.6 hours with placebo (PMID 25331030). The comparison was p = 0.15. The authors found no significant difference in the main or other effect checks.
At least one adverse event after treatment occurred in 87.5% of the active group and 94.8% of the placebo group (PMID 25331030). The accessible abstract calls the peptide well tolerated. It does not give event counts by type or name a serious event.
Funding: Helsinn Therapeutics supported the study. The authors' institutions received Helsinn grants to conduct it. Helsinn also supported manuscript development. The authors declared no financial or proprietary conflicts. These facts and results were checked 22 August 2026.
What happened to the larger phase 2 trial?
NCT01280344 was a separate randomized, double-blind, placebo-controlled phase 2 trial. It tested the peptide by vein after bowel surgery. The registry gives an actual enrollment of 320. Helsinn Therapeutics was the sponsor.
The study completed in May 2014 (NCT01280344). The registry posts no results. It links no results paper. It gives no reason for the absence. These registry facts were checked 22 August 2026.
The exact ClinicalTrials.gov search returned three records on 22 August 2026. The third record, NCT07717866, is an observational study with 52 actual participants. The peptide appears inside a bundled supplement programme. The design has no group for it alone. It cannot isolate its effect.
Did human studies measure muscle gain, recovery, sleep, or fat loss?
No published human result for muscle gain, workout recovery, sleep, fat loss, or healthy ageing was found. This is an absence in the exact-name trial search. It is not proof that an effect cannot exist.
The exact PubMed clinical-trial search returned two papers on 22 August 2026. They were PMID 10496658 and PMID 25331030. The first measured growth hormone in healthy men. The second tested gut recovery after surgery.
The 320-person study has no public result. The third registry record bundles the peptide with several other parts. None of these records reports the marketed outcomes above.
What ipamorelin side effects did the human studies record?
The 1999 abstract reports no adverse-event result (PMID 10496658). The 2014 abstract reports overall events after treatment, not a full table by event.
In the 2014 trial, 87.5% of the active group and 94.8% of the placebo group had at least one event after treatment (PMID 25331030). The study involved hospital patients after bowel surgery. The percentages are not rates for healthy users or current products.
The FDA page in the US makes a separate statement. It says a published study found serious events, including death, when the peptide was given by vein for gut motility. The accessible abstract of the only exact published trial of this kind does not mention death. The full trial text is not open. We therefore cannot establish whether the FDA in the US refers to that paper or another source.
The FDA in the US also says it lacks safety information for some other injectable routes. This is a US agency statement about an evidence gap. It is not a measured adverse-event rate.
These study and US FDA claims were checked 22 August 2026.
What does one user report about ipamorelin with CJC-1295?
Mike Jason Pascual described using the peptide with a product labelled CJC-1295 without DAC. The original ExcelMale thread was opened in a browser on 22 August 2026.
So, far so good. [...] Workouts are excellent. [...] I feel a little groggy in the morning.
The omitted words give an amount and schedule. This is one self-reported and self-selected account. The post cannot separate the two peptides. No lab checked the products. No payment is disclosed for the post. The complete thread is linked so the reader can weigh the account directly.
What have ipamorelin product tests found?
A peer-reviewed Danish paper analyzed seized powders (PMID 30136411). The tests found analogues of four named GH-releasing compounds, including this peptide. Every analogue had an extra glycine at one end. The abstract does not print how many ipamorelin preparations were tested. The PubMed record lists no grant support. These details were checked 22 August 2026.
A 2026 preprint analyzed 6,487 reports sent in by choice across 14 peptides (DOI 10.20944/preprints202604.1748.v1). It has not been peer-reviewed. It reports 6 identity failures for ipamorelin. The opened text gives no percentage or group total for the peptide.
Under the authors' stricter model, 34.2% of ipamorelin reports passed both the amount and purity limits. This was the second-highest rate among the 14 peptides. The model required 95% to 105% of label amount and at least 99.5% purity. These are the authors' limits for comparison. They are not official release decisions for the vials.
People and peptide companies chose which reports to send. The sample was not a random market survey. The tests measured identity, amount, and purity by chromatography. Only 243 reports across all 14 peptides included endotoxin tests. They did not establish sterility for the peptide group. The preprint reports no external funding. Its authors declared no conflict of interest. These details were checked 22 August 2026.
The vial-testing guide explains what identity, amount, purity, endotoxin, and sterility tests answer separately.
What does EMA's central register show for ipamorelin?
Rules differ by country. EMA made its report on 22 August 2026. It held 2,731 medicine rows. No row matched ipamorelin.
The search covers only EMA's central EU route. It does not cover national registers. Ipamorelin's status in Europe therefore stays unclear. Checked 22 August 2026.
What does the FDA say about ipamorelin compounding in the US?
For compounding in the US, the FDA's current page lists the acetate form in the 503B Category 2 table. The page also lists a separate nomination for that form in its withdrawn-nominations table. These are different table placements on the same page.
The US agency cites possible immune responses. It cites clumping and peptide impurities. It also cites unnatural amino acids and problems identifying the exact compound. The page publishes the serious-event statement above. This is the FDA's US risk assessment. It is not another clinical trial result.
These US status claims were checked 22 August 2026.
Primary FDA source in the US: current bulk-substance safety-risk page.
Where can a reader go next?
The training and recovery hub compares human and vial evidence across related compounds. The ipamorelin register record keeps evidence and regulatory status separate. The CJC-1295 guide covers the other compound in the forum account.