Ipamorelin: human evidence, safety and FDA status
A growth-hormone secretagogue with limited clinical evidence. Compare the surgical trial, safety findings and requirements for authorized research.
The short answer
Ipamorelin is a synthetic peptide that stimulates growth-hormone release through the ghrelin receptor. Human records include IV pharmacokinetic and postoperative studies, reported exposures by other routes and a newer multimodal protocol. They do not establish dependable wellness benefits or long-term safety. It is not FDA-approved; authorized investigation and retail eligibility are separate.
Definition
Ipamorelin (ipamorelin acetate, NNC 26-0161) is a synthetic peptide that triggers growth-hormone release by mimicking ghrelin, the body's hunger hormone. It is not FDA-approved.
Key takeaways
- Ipamorelin is a synthetic ghrelin-receptor agonist that can stimulate growth-hormone release; it is not FDA-approved.
- Animal selectivity findings do not establish a superior human safety profile or predictable wellness benefit.
- A published postoperative trial missed its primary endpoint. FDA describes serious events, including two deaths with uncertain drug causality in a medically complex population.
- IV studies are not the whole exposure record: FDA also describes nasal and subcutaneous reports, while a newer multimodal protocol supplies no isolatable ipamorelin result.
- Advisory votes were 0 yes, 12 no, 1 abstention on each reviewed form. Current records do not establish ordinary retail bulk eligibility; WADA prohibits ipamorelin at all times.
Key facts
| Fact | Detail |
|---|---|
| Other names | Ipamorelin acetate, ipamorelin free base, NNC 26-0161 |
| Type | Growth-hormone secretagogue peptide, sold as a research compound |
| FDA approval | Never approved |
| 503A pharmacy compounding | Current regulation and interim records do not establish ordinary retail bulk eligibility[10] |
| Advisory vote, October 29, 2024 | 0 yes, 12 no, 1 abstain, on each form[3] |
| 503B outsourcing | Acetate appears in current Category 2 under the 503B interim policy; this nomination document is not the complete final legal framework[12] |
| Human studies | IV PK and postoperative reports, additional exposure reports and newer protocol records; clinical wellness benefit unestablished |
| Sport | WADA Prohibited List 2026, S2.2.4[8] |
Ipamorelin is often marketed with CJC-1295, but a shared growth-hormone rationale is not a combination trial. The best-known published clinical reports are an IV pharmacokinetic study and a postoperative trial [6] [7]. Other reported exposures and newer protocols mean those two publications should not be described as the entire human record. FDA’s advisory transcript records no votes in favor of listing either reviewed form [3].
Ipamorelin is a lab-made ghrelin mimic that releases growth hormone
Your body has two main signals for growth-hormone release. One is growth-hormone-releasing hormone, the signal sermorelin copies. The other runs through the ghrelin receptor. Ipamorelin works on the second one: the 2014 phase 2 trial describes it as a ghrelin-receptor agonist, a "ghrelin mimetic" [7].
It came out of a drug-development program in the 1990s. The paper that introduced it describes a pentapeptide, a chain of five amino acids, built by modifying an earlier growth-hormone-releasing peptide [5]. FDA notes that it contains unnatural amino acids, which is one reason it raised immune-reaction concerns [4]. It contains no growth hormone.
Why it's called "selective": an animal finding that hasn't been tied to any human benefit
Ipamorelin's selling point is selectivity. In rat pituitary cells and in pigs, it released growth hormone about as strongly as an older peptide, GHRP-6 [5]. Unlike GHRP-6 and GHRP-2, it did not raise the stress hormones ACTH and cortisol, even at doses more than 200 times higher than the one needed for growth-hormone release.
That made it, in the authors' words, an interesting candidate for development [5]. It hasn't been shown to matter for any human outcome. No published trial has compared ipamorelin with another secretagogue on side effects in people, so the "cleaner" reputation rests on animal pharmacology.
Selected human studies and additional records
Gobburu’s published IV study examined pharmacokinetics and growth-hormone response in healthy men, with eight participants at each of five dose levels [6]. It described a single hormone pulse, not a validated muscle, sleep or aging benefit. The IV route also limits inference about an injected commercial product.
Beck’s randomized postoperative study enrolled 117 adults, with 114 receiving IV ipamorelin or placebo [7]. Median time to the first tolerated solid meal was 25.3 versus 32.6 hours (P=.15). The primary comparison was not statistically significant; that does not prove the true effect is exactly zero or establish a wellness benefit in healthy people.
A separate registry reports 320 actual participants, primary completion in June 2013 and overall completion in May 2014, with no posted results [1]. Its size must not be mistaken for available outcome data. The newer 52-participant multimodal observational record names ipamorelin among physiological-supplementation options alongside other interventions; it has no posted results and cannot isolate ipamorelin, establish that all participants received it or validate a CJC-1295 combination [13].
| Study | Population | Design and size | What it found | Strength of evidence |
|---|---|---|---|---|
| Raun 1998 [5] | Rat cells, rats, pigs | Preclinical pharmacology | Growth-hormone release like GHRP-6, without ACTH or cortisol rises | Not human evidence |
| Gobburu 1999 [6] | Healthy men, 8 per dose level | Dose-escalation pharmacokinetic study, IV | Half-life about 2 hours; single GH pulse peaking at about 0.67 hours | PK and hormone response, not wellness efficacy |
| Beck 2014 [7] | 117 adults after bowel surgery (114 analyzed) | Randomized, double-blind, placebo-controlled phase 2, IV | Time to first meal 25.3 vs 32.6 hours, not significant | Selected postoperative population; primary comparison nonsignificant |
| Additional records [2] [13] | Reported nasal/subcutaneous exposure; multimodal program | Not isolated randomized wellness evidence | No dependable effect or safety rate established | Do not treat all human information as only two IV publications |
How long ipamorelin lasts in the body: a half-life of about 2 hours
In healthy men given ipamorelin by IV infusion, its terminal half-life was about 2 hours. The growth-hormone response peaked at about 0.67 hours, roughly 40 minutes, then fell to negligible levels [6].
That study used IV infusion, and half-life is different from effect duration or a sports-test detection window. FDA’s assessment describes a nasal exposure report and a two-month subcutaneous combination with sermorelin, but these adverse-event reports do not establish route-specific controlled pharmacokinetics [2]. The fluid-retention review explains the limits of symptom attribution.
Safety: what FDA found in the trial record
FDA's 2024 briefing went back through the phase 2 trial and pulled out what concerned it. Two patients in the ipamorelin group died after colon-cancer surgery and serious postoperative complications; FDA said it was unclear whether the deaths were related to ipamorelin [2]. Serious adverse events, such as infection and leaks at the surgical join, occurred in 17.9% of the ipamorelin group and 15.5% of the placebo group.
FDA reports hyperglycemia at discharge in 14.3% versus 8.6%, insomnia in 10.7% versus 5.2%, and hypokalemia in 12.5% versus 3.4% [2]. These are numerical comparisons from postoperative patients, not proven drug-caused rates in healthy users. Three participants in each arm discontinued for adverse events.
| Finding | Ipamorelin | Placebo |
|---|---|---|
| Serious adverse events | 17.9% | 15.5% |
| High blood sugar at discharge | 14.3% | 8.6% |
| Insomnia | 10.7% | 5.2% |
Patients were recovering from bowel surgery and received IV ipamorelin for up to 7 days; these numbers don't describe healthy adults using it at home.
FDA identifies potential aggregation, impurity and immune-reaction concerns and discusses risks associated with GH/IGF-1 elevation [4] [2]. Its two-month subcutaneous report involved ipamorelin plus sermorelin and joint pain; the mixture prevents attribution to ipamorelin alone. The combination safety review separates a plausible mechanism from an established human risk estimate.
How ipamorelin went from a surgery drug candidate to a wellness peptide
The 1998 pharmacology paper and later postoperative development address different questions from today’s wellness marketing [5] [7]. The published postoperative trial, larger unpublished registry and newer multimodal protocol should be interpreted separately rather than treated as one continuous proof of benefit.
FDA describes marketing for weight loss, sleep, anti-aging and bodybuilding [2]. The reviewed studies and current protocol do not establish dependable benefits for these uses. The combination efficacy review addresses the separate question of paired treatment.
Current retail eligibility is separate from research authorization
Ipamorelin is not FDA-approved. FDA’s assessment identifies no applicable monograph or component of an approved drug for the reviewed forms [2]. Current 503A regulation does not list it; the reviewed records do not establish ordinary retail bulk eligibility [10].
FDA evaluated ipamorelin for the two uses its nominators named: growth-hormone deficiency and slow gut recovery after surgery [2]. For growth-hormone deficiency, FDA's presenter told the committee there were no studies in deficient patients and no data on whether ipamorelin raises growth hormone in them, and noted that FDA-approved treatments with established efficacy already exist [3]. For gut recovery, the published trial’s primary endpoint was not statistically significant.
The assessment weighs substance characterization, compounding history, safety and effectiveness rather than treating demand as clinical proof. Those assessment criteria and the nonbinding advisory ballots are different from a final product approval or investigational authorization [2].
The primary transcript records 0 yes, 12 no and 1 abstention for each form on the listing question [3]. No member voted for inclusion; these advisory ballots are different from a product-approval decision. The broader pending peptide-policy notice does not publish final terms or establish ipamorelin eligibility [9].
FDA’s current primary documents retain ipamorelin acetate in Category 2 under its 503B interim policy [12] [4]. A nomination-category document is not the final bulks rule or a complete statement of all legal conditions.
| Version | FDA-approved? | Lawful path | What it means for you |
|---|---|---|---|
| 503A product | Not FDA-approved | Ordinary retail bulk eligibility not established | A prescription alone does not establish an exemption |
| 503B product | Not FDA-approved | Acetate in current interim Category 2 | Registration does not establish product eligibility |
| Research-use label | Not FDA-approved | Label alone does not establish human-treatment authorization | Confirm applicable research oversight and authorization |
A CJC-1295 pairing needs separate evidence
Pairing with CJC-1295 is marketed on a two-receptor rationale. The recorded primary literature and registry searches did not identify an administered-pair trial that establishes wellness efficacy or safety. Different single-molecule data cannot supply that missing comparison. Read the CJC-1295 and ipamorelin review.
Ipamorelin vs sermorelin: different signals, very different legal footing
Related peptides have different records. Historical sermorelin approvals do not approve current compounded products. Tesamorelin has approved Egrifta formulations for excess abdominal fat in adults with HIV-associated lipodystrophy. Those facts do not establish head-to-head superiority or identical risks. See the scoped sermorelin comparison and tesamorelin comparison.
Ipamorelin is banned in sport at all times
WADA's 2026 Prohibited List names ipamorelin under S2.2.4 among growth-hormone secretagogues and their mimetics, prohibited in and out of competition [8].
A prescription or research label is not an authorization
Properly authorized clinical investigation has separate requirements for manufacturing information, nonclinical evidence, protocol review and oversight [11]. Trial registration alone does not establish all applicable authorization. Neither a commercial prescription nor a research-use label supplies that authorization or proves product quality.
Tell your clinician about any prior ipamorelin exposure and its source. Product identity, other ingredients and the reason for treatment affect how an adverse event can be interpreted. Neither a reassuring laboratory result nor an anecdotal symptom list establishes safety of an unidentified product.
If your interest is growth hormone, the useful conversation is with a clinician: ask whether testing for growth-hormone deficiency makes sense for you, and what approved options exist if it does. How this site grades evidence is in how we check.
Terms used on this page
- Growth-hormone secretagogue: a substance that makes the pituitary release growth hormone.
- Ghrelin mimetic: a molecule that acts on the ghrelin receptor, one of the pituitary's growth-hormone signals.
- 503B outsourcing facility: an FDA-registered compounder that can make larger lots; its own list of allowed ingredients is separate from the 503A list.
- Research use only (RUO): a label on lab chemicals; the label alone does not establish authorization for human treatment.
- PCAC: FDA's Pharmacy Compounding Advisory Committee. Its votes advise FDA; they don't bind it.
Research on Ipamorelin
What the ipamorelin bowel-surgery trial actually showed
The published postoperative trial did not find a statistically significant improvement in its primary meal-tolerance endpoint. Its short intravenous protocol in surgical patients cannot establish routine wellness benefits or subcutaneous safety.
What does CJC-1295 with ipamorelin do? What's studied, what isn't, and FDA's votes
Two peptides target different growth-hormone signals. Compare the measured individual-drug findings, combination evidence gaps and current FDA records.
Does CJC-1295 with ipamorelin work? What has actually been tested
Clinics sell CJC-1295 and ipamorelin together for fat loss, muscle, sleep and recovery. Here is selected human reports and current registered research, and what each one measured.
Does ipamorelin cause water retention? What the safety record shows
Bloating, joint pain and fluid-related swelling are different outcomes. The reviewed human evidence does not establish a reliable chronic-use rate.
Is CJC-1295 with ipamorelin safe? What the trials and FDA's reviews show
Small individual-drug studies and uncertain adverse-event reports cannot establish the safety of a combination. Read the source populations and study limits.
Ipamorelin compared
Sermorelin vs ipamorelin: one is compounded, one has no pharmacy route
Both raise growth hormone, but through different receptors, with different trial records and a very different standing with FDA. Here is the side-by-side, with the dates.
Tesamorelin vs ipamorelin: an approved brand and a peptide that never was
One has two phase 3 trials and an FDA label. The other has one failed phase 2 trial and a unanimous vote against it. Neither has a pharmacy route, and that changes what "better" can mean.
Frequently asked
- Is ipamorelin FDA approved?
- No. FDA’s October 2024 advisory listing ballots were 0 yes, 12 no and 1 abstention for each reviewed form. That advice is different from product approval or investigational authorization.
- Is ipamorelin a steroid?
- No. Ipamorelin is a peptide that makes the pituitary release growth hormone. It is not an anabolic steroid, though WADA bans it at all times.
- Does ipamorelin cause water retention?
- A reliable human rate in healthy users is unestablished by the reviewed evidence. FDA discusses fluid-retention risks on approved GH labels as a reason for concern, not a measured ipamorelin event rate.
- How long does ipamorelin stay in your system?
- The published IV study reports a terminal half-life near two hours and a growth-hormone peak around 40 minutes. This is not a subcutaneous schedule, effect duration or sports-test detection window. Reported exposure by other routes does not supply controlled route-specific PK.
- Is ipamorelin legal to buy online?
- Current records do not establish an approved product or ordinary retail bulk eligibility. Authorized investigation is separate; a prescription, research label or registry entry alone does not establish an exemption or authorization.
- Is ipamorelin banned in sports?
- Yes. WADA's 2026 Prohibited List names ipamorelin under S2.2.4, growth-hormone secretagogues, which are prohibited at all times.
Sources
- [1] ClinicalTrials.gov NCT01280344: phase II dose-finding study of ipamorelin vs placebo after bowel resection (accessed 2026). Source
- [2] FDA. Ipamorelin free base and ipamorelin acetate: briefing document, Pharmacy Compounding Advisory Committee, October 29, 2024. FDA
- [3] FDA. Pharmacy Compounding Advisory Committee meeting transcript, October 29, 2024. FDA
- [4] FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (accessed 2026). FDA
- [5] Raun K. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol (1998). PMID 9849822
- [6] Gobburu JV. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res (1999). PMID 10496658
- [7] Beck DE. 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). PMID 25331030
- [8] World Anti-Doping Agency. Prohibited List 2026 (in effect January 1, 2026), section S2.2.4 (2026). Source
- [9] OIRA pending review: Interim Access Policy for Compounding Using Certain Peptides (accessed 2026). Source
- [10] Current 21 CFR 216.23: 503A bulks regulation (accessed 2026). Source
- [11] FDA: Investigational New Drug framework (accessed 2026). FDA
- [12] FDA: 503B nominated bulk substances, updated March 21, 2025. FDA
- [13] ClinicalTrials.gov: multimodal observational veteran program; no posted results (accessed 2026). Source