Ipamorelin Benefits: Claims vs What Studies Show
Benefits people claim for Ipamorelin, set against what published studies measured, and where no study exists.
- Strongest evidence
- Human RCT
- Human / animal studies
- 2 / 9
- in our evidence file (PubMed search, 11 Oct 2026)
- FDA status
- Not approved
- research chemical
Claimed benefits and what studies show
Each row is an area where people claim a benefit, with the strongest study we summarise behind it. Animal and cell results are labelled and are not human results. User reports are not counted as evidence here.
| Claim | Best evidence | Studies (human / animal) | What was measured | Page |
|---|---|---|---|---|
| Growth hormone | Human RCT evidence, 4 of 4 | 1 / 1 | GH release; Selectivity for GH release; ACTH and cortisol | Evidence for growth hormone |
| Muscle growth | Review only | 0 / 3 | Regulatory status and evidence for physique claims; Muscle strength and bone formation under glucocorticoid; Body weight and bone mineral content | Evidence for muscle growth |
| Weight loss | Review only | 0 / 0 | Regulatory status and evidence for physique claims | Evidence for weight loss |
Strongest study per claim: Growth hormone, Pharmaceutical research 1999, PMID 10496658; Muscle growth, Frontiers in endocrinology 2026, PMID 42395176; Weight loss, Frontiers in endocrinology 2026, PMID 42395176.
What the studies measured
| Outcome | Result | Study type | Source |
|---|---|---|---|
| Time to first tolerated meal | Median time to first tolerated meal was 25.3 h with ipamorelin and 32.6 h with placebo, a difference that was not statistically significant. | Human RCTn = 117 | International journal of colorectal disease 2014, PMID 25331030 |
| Overall efficacy | No significant difference from placebo in the key or secondary efficacy analyses. | Human RCTn = 117 | International journal of colorectal disease 2014, PMID 25331030 |
| GH release | A single episode of GH release peaked at 0.67 hours and fell to negligible levels at all doses. | Human RCT | Pharmaceutical research 1999, PMID 10496658 |
| Regulatory status and evidence for physique claims | The review notes no regulatory approval for physique- or performance-related indications of these peptides, including ipamorelin. | Review | Frontiers in endocrinology 2026, PMID 42395176 |
| Cisplatin-induced weight loss | Ipamorelin did not change emesis but reduced cisplatin-induced weight loss by approximately 24% on the last day of the delayed phase (48-72 h). | Animal · ferret (not a human result) | Physiology & behavior 2024, PMID 39043357 |
| Visceral and somatic pain behaviour | Ipamorelin reduced colonic hypersensitivity and paw allodynia in rats; the models are not joint or back pain models. | Animal · rat (not a human result) | Journal of experimental pharmacology 2020, PMID 32801950 |
| Gastric emptying | After surgery 78% of the meal remained in the stomach in vehicle rats versus 52% with ipamorelin 0.014 umol/kg (44% in non-surgical controls). | Animal · rat (not a human result) | Journal of experimental pharmacology 2012, PMID 27186127 |
| Food intake and weight gain | Repeated dosing at 0.1 or 1 mg/kg increased fecal output, food intake and body weight gain in rats after surgery. | Animal · rat (not a human result) | The Journal of pharmacology and experimental therapeutics 2009, PMID 19289567 |
| Muscle strength and bone formation under glucocorticoid | Adding ipamorelin to glucocorticoid increased calf-muscle tetanic tension and raised periosteal bone formation four-fold versus glucocorticoid alone. | Animal · rat (not a human result) | Growth hormone & IGF research 2001, PMID 11735244 |
| Body weight and bone mineral content | Ipamorelin, another GHRP and GH all increased body weight and bone mineral content versus vehicle; BMC per body weight was unchanged. | Animal · rat (not a human result) | The Journal of endocrinology 2000, PMID 10828840 |
| Bone growth and body weight | Longitudinal bone growth rose dose-dependently from 42 microm/day (vehicle) to 44, 50 and 52 microm/day, with dose-dependent body weight gain. | Animal · rat (not a human result) | Growth hormone & IGF research 1999, PMID 10373343 |
| Selectivity for GH release | Ipamorelin released GH with selectivity similar to GHRH in these preclinical models. | Animal · rat and swine (plus rat pituitary cells in vitro) (not a human result) | European journal of endocrinology 1998, PMID 9849822 |
| ACTH and cortisol | Unlike other GHRP agonists, ipamorelin did not raise ACTH or cortisol beyond GHRH-stimulated levels in swine. | Animal · rat and swine (plus rat pituitary cells in vitro) (not a human result) | European journal of endocrinology 1998, PMID 9849822 |
| Clearance and nasal absorption | Intranasal bioavailability of ipamorelin in rats was approximately 20%. | Animal · rat (not a human result) | Xenobiotica; the fate of foreign compounds in biological systems 1998, PMID 9879640 |
The growth hormone release claim
Claim: ipamorelin releases growth hormone. In healthy male volunteers given intravenous infusions, a single episode of GH release followed each dose, peaking at 0.67 hours.[2]
Claim: it is selective for GH. A pharmacology paper (in cells, rats and swine) reports that ipamorelin did not raise ACTH or cortisol above the level seen after GHRH stimulation.[11]
The muscle-growth claim
Claim: it builds muscle. No human muscle study is cited. In rats given a glucocorticoid, adding ipamorelin increased the maximum tetanic tension of the calf muscles and increased the periosteal bone formation rate four-fold.[8]
In adult female rats, ipamorelin gave a pronounced, dose-dependent effect on body weight gain. This is animal data.[10]
A review of performance-enhancing peptides highlights the uncertainty around putative performance and recomposition benefits.[3]
Weight and appetite claims
Claim: it prevents weight loss. In ferrets given cisplatin, ipamorelin inhibited cisplatin-induced weight loss on the last day of the delayed phase by approximately 24%. This is animal data.[4]
In rats after abdominal surgery, repeated ipamorelin dosing significantly increased fecal pellet output, food intake and body weight gain.[7]
The one human efficacy trial
In a bowel-surgery trial, ipamorelin did not beat placebo: median time to first tolerated meal was 25.3 versus 32.6 h (p = 0.15).[1]
Its authors conclude there were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses.[1]
More on Ipamorelin
Common questions
Is Ipamorelin proven to work?
The strongest study we summarise for Ipamorelin is human rct evidence, among 12 studies. A trial result is not an approval; see the legal status.
What does ipamorelin do?
Ipamorelin is described as a pentapeptide with high growth-hormone-releasing potency and efficacy, both in vitro and in vivo.[11]
More on Ipamorelin
Sources
- 1Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients.International journal of colorectal disease · 2014PMID 25331030Accessed 2 Oct 2026
- 2Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.Pharmaceutical research · 1999PMID 10496658Accessed 2 Oct 2026
- 3The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration.Frontiers in endocrinology · 2026PMID 42395176Accessed 2 Oct 2026
- 4The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism.Physiology & behavior · 2024PMID 39043357Accessed 2 Oct 2026
- 5Attenuation of Visceral and Somatic Nociception by Ghrelin Mimetics.Journal of experimental pharmacology · 2020PMID 32801950Accessed 2 Oct 2026
- 6Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus.Journal of experimental pharmacology · 2012PMID 27186127Accessed 2 Oct 2026
- 7Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus.The Journal of pharmacology and experimental therapeutics · 2009PMID 19289567Accessed 2 Oct 2026
- 8The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats.Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2001PMID 11735244Accessed 2 Oct 2026
- 9The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats.The Journal of endocrinology · 2000PMID 10828840Accessed 2 Oct 2026
- 10Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats.Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 1999PMID 10373343Accessed 2 Oct 2026
- 11Ipamorelin, the first selective growth hormone secretagogue.European journal of endocrinology · 1998PMID 9849822Accessed 2 Oct 2026
- 12Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.Xenobiotica; the fate of foreign compounds in biological systems · 1998PMID 9879640Accessed 2 Oct 2026
- 13PubMed search: ipamorelin[tiab] (50 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
- 14PubMed search: ipamorelin[tiab] AND (half-life[tiab] OR pharmacokinetic*[tiab]) (4 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
- 15PubMed search: ipamorelin[tiab] AND (adverse[tiab] OR "side effect*"[tiab] OR safety[tiab] OR tolerab*[tiab] OR toxicity[tiab] OR "case report"[pt]) (11 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 11 Oct 2026
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