Peptide evidence preview
Ipamorelin: Safety, Legal Status, and Human Evidence
Ipamorelin is an unapproved ghrelin-receptor agonist whose only controlled human trial was negative. Mechanism, FDA safety findings, and WADA status.
Also known as: NNC 26-0161 · Ipamorelin acetate
Direct answer
Direct answer
Ipamorelin is a synthetic peptide that activates the ghrelin receptor and stimulates endogenous growth-hormone release. It has never been approved by FDA or Health Canada. Its selectivity is documented mainly in preclinical studies. The strongest controlled human trial, in postoperative ileus, did not show a significant benefit on its key or secondary efficacy outcomes, and marketed wellness claims remain unproven.
Status at a glance
As of October 27, 2026
- United States (FDA)
- Not approved for any indication. No ipamorelin product is listed in Drugs@FDA. U.S. Food and Drug Administration
- FDA compounding
- Ipamorelin acetate is in category 2 (may present significant safety risks) under the 503B interim policy since September 29, 2023, and is also listed as nominated but withdrawn. U.S. Food and Drug Administration
- Canada (Health Canada)
- No authorized drug product in Health Canada's Drug Product Database. Health Canada
- Sport (WADA)
- Prohibited at all times under class S2.2.4, which names ipamorelin among growth hormone secretagogues. World Anti-Doping Agency
WADA updates its Prohibited List every January; the 2027 List takes effect January 1, 2027. Athletes should check the list in force and their own federation's rules.
Public Evidence Passport preview
Preclinical mechanism + negative controlled human trial
The biological mechanism is supported mainly by laboratory and animal work. A controlled human program reached mid-stage testing but did not demonstrate a significant efficacy benefit for the studied indication.
- Strongest source tier
- Tier 4 — randomized controlled human trial
- Editorial review
- August 4, 2026
- Source coverage
- 9 inspectable records in this public preview
What matters
- The receptor mechanism is well characterized, but much of the selectivity evidence is preclinical.
- The completed controlled human trial was negative for the indication studied.
- Consumer claims around body composition, recovery, sleep, and healthy aging lack adequate controlled human support.
- Long-term human safety is not established, and ipamorelin is not approved for a clinical use in the United States or Canada.
Has ipamorelin been studied in humans?
Yes. A randomized trial studied recovery after bowel surgery. Its efficacy results did not show a significant advantage over placebo; it does not establish benefits for sleep, muscle gain, or general recovery.
| Source | Study design | Finding | Limit |
|---|---|---|---|
| Beck et al., 2014 | Multicenter, double-blind, placebo-controlled trial. 117 adults enrolled after bowel resection; 114 in the reported analysis populations. | No significant difference in the key or secondary efficacy analyses. | A small trial in surgical patients does not answer marketed wellness questions. |
| Raun et al., 1998 | Laboratory and animal pharmacology, including rat cells, rats, and swine. | Growth-hormone release and selectivity were characterized in these models. | These findings describe preclinical activity, not clinical benefit in people. |
Source notes updated . Added the human trial's study population, comparison, outcome, and limits, alongside the foundational preclinical paper.
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A peptide claim is easier to judge when you can inspect the study behind it. Open a public evidence preview in Peptidia and find What the sources support. Read the study design first. Was it a human trial, an animal experiment, or a laboratory study? Note the population and the comparison group. Next, read the finding and its limit together. A biological effect does not establish a useful clinical benefit. A study in one patient group may not answer a different health question. Follow the source link to inspect the original record. Check what changed in the source notes and keep the review date in view. Peptidia is an educational reference. It does not prescribe treatments or provide doses.
Mechanism
Ipamorelin acts as an agonist of the growth hormone secretagogue receptor, also called the ghrelin receptor. Receptor activation stimulates the pituitary release of endogenous growth hormone. Foundational animal and laboratory studies reported more selective hormone release than earlier secretagogues.
That selectivity advantage should be described carefully: controlled human endocrine evidence is sparse, and a mechanistic description does not establish a useful clinical outcome.
What the human evidence found
Ipamorelin advanced to a multicenter, double-blind, placebo-controlled study in adults after bowel resection. The study enrolled 117 patients and did not find a statistically significant difference on its key efficacy endpoint, time to a tolerated solid meal, or on its secondary efficacy analyses. The authors describe it as small, with patients who had a broad range of underlying conditions. The trial registry lists an industry sponsor, Helsinn Therapeutics.
The contrast between positive rodent gastrointestinal findings and the negative human trial is an instructive example of why preclinical activity cannot be assumed to translate.
What remains uncertain
There are no adequate controlled human trials establishing the marketed wellness, body-composition, muscle, sleep, or recovery claims commonly associated with ipamorelin. Long-term safety is also insufficiently characterized.
Growth-hormone and related signaling raises safety questions involving glucose regulation, fluid retention, and proliferative pathways. Those questions require individualized clinical assessment and cannot be resolved by an educational profile.
FDA's compounding safety-risk list cites a published study, which it does not name on that page, that identified serious adverse events, including death, when ipamorelin was given intravenously to improve gastric motility. FDA also notes possible immunogenicity and impurity concerns for compounded ipamorelin acetate.
Regulatory context
Ipamorelin is not approved by the U.S. Food and Drug Administration or Health Canada for a clinical indication. Availability through an unapproved or compounded channel is a separate question from evidence of benefit, product quality, and individual safety.
FDA places ipamorelin acetate in category 2 under its 503B interim policy for compounding. WADA prohibits ipamorelin in and out of competition as a growth hormone secretagogue.
Common questions
Is ipamorelin FDA approved?
No. Ipamorelin has never been approved by FDA or Health Canada for any indication, and no ipamorelin product is listed in Drugs@FDA. FDA places ipamorelin acetate in category 2, substances that may present significant safety risks, under its 503B compounding policy.
Sources:Drugs@FDA: FDA-approved drugsCertain bulk drug substances for use in compounding that may present significant safety risks
Is ipamorelin safe?
Not established. The postoperative ileus trial authors reported that it was well tolerated in that study. FDA, however, cites a published study that identified serious adverse events, including death, after intravenous use for gastric motility. Long-term human safety has not been studied.
Sources:Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patientsCertain bulk drug substances for use in compounding that may present significant safety risks
Is ipamorelin the same as MK-677?
No. Both are growth hormone secretagogues, and WADA lists both in that group. Ipamorelin is a peptide that acts on the ghrelin receptor, while MK-677 (ibutamoren) is an orally available small molecule rather than a peptide.
Sources:The Prohibited ListIpamorelin, the first selective growth hormone secretagogueProspective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patientsThe Safety and Efficacy of Growth Hormone Secretagogues
What is the difference between ipamorelin and sermorelin?
They act on different receptors. Ipamorelin is a growth hormone secretagogue that activates the ghrelin receptor. Sermorelin is an analog of growth hormone-releasing hormone, which acts through a different receptor. WADA lists them in separate groups within the same prohibited class.
Sources:The Prohibited ListIpamorelin, the first selective growth hormone secretagogueProspective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients
Does ipamorelin build muscle?
Not established. There are no adequate controlled human trials of ipamorelin for muscle gain, fat loss, sleep, or recovery. Those claims rest on extrapolation from growth hormone physiology and on small or preclinical data.
Sources:Ipamorelin, the first selective growth hormone secretagogueProspective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients
Is ipamorelin banned in sport?
Yes. WADA prohibits ipamorelin at all times, in and out of competition, under class S2.2.4. The list names ipamorelin directly among growth hormone secretagogues.
Sources:The Prohibited List
Inspect the record
Sources
- 01Ipamorelin, the first selective growth hormone secretagoguePubMed
Foundational preclinical characterization.
- 02Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patientsPubMed
Strongest controlled human evidence; efficacy analyses were negative.
- 03Safety and Efficacy of Ipamorelin for Management of Post-Operative IleusClinicalTrials.gov
Registry record for the phase 2 trial; industry sponsored.
- 04Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileusPubMed
Preclinical result that did not establish human benefit.
- 05The Safety and Efficacy of Growth Hormone SecretagoguesPubMed
Narrative review of the secretagogue class, including ibutamoren.
- 06Drugs@FDA: FDA-approved drugsU.S. Food and Drug Administration
Searched for ipamorelin on 2026-10-27; no product found.
- 07Certain bulk drug substances for use in compounding that may present significant safety risksU.S. Food and Drug Administration
Regulator safety-risk list; checked 2026-10-27.
- 08Drug Product Database online queryHealth Canada
Searched for ipamorelin on 2026-10-27; no product found.
- 09The Prohibited ListWorld Anti-Doping Agency
2026 list, class S2.2.4.
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