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Ipamorelin vs CJC-1295
CJC-1295 is a GHRH analogue and ipamorelin a ghrelin-receptor agonist: different receptors, different sizes. What is and is not established.
By the Ipamorelin Research editorial team · Last reviewed · Scientific review: pending
Short answer
Ipamorelin and CJC-1295 act at two different receptors. Ipamorelin is a five-residue ghrelin-receptor agonist acting at GHSR-1a; CJC-1295 is a 29-residue GHRH analogue acting at the GHRH receptor. They are five times apart in molecular weight. Neither is an approved drug, and no controlled human trial of either compound in combination with the other is indexed in this database.
| Field | Ipamorelin | CJC-1295 |
|---|---|---|
| Classification | Synthetic pentapeptide growth hormone secretagogue | GHRH analogue, supplied with or without a drug affinity complex |
| Receptor target | GHSR-1a | GHRH receptor |
| Molecular formula | C38H49N9O5 | C165H269N47O46 |
| Molecular weight | 711.9 | 3647.2 |
| Size | 5 residues, C-terminal amide; three non-standard residues | 29-residue analogue, about five times the mass of ipamorelin |
| Half-life | About 2 hours | Not verified for this site |
| Human clinical evidence | 1 randomised trial (null on efficacy); 1 dose-escalation PD study; 1 trial of 320 never reported | No controlled human trial of the combination is indexed here |
| Regulatory status | Not approved; FDA Category 2; advisory committee voted against 503A listing | Not approved |
Two receptors, not one
This is the substantive difference and everything else follows from it. Growth hormone release from the pituitary is regulated by two separate inputs: growth hormone-releasing hormone acting at the GHRH receptor, and ghrelin acting at GHSR-1a. CJC-1295 is an analogue of the first; ipamorelin is an agonist at the second. Ipamorelin's receptor was established by antagonist profiling, which showed it acts through a GHRP-like receptor and specifically not through the GHRH receptor [Raun 1998]. The step-by-step pathway for ipamorelin is on the mechanism page.
Why the two are so often named together
Because they act at different receptors, the pharmacological argument for pairing them is that each adds an input the other does not. That argument is coherent. What it is not is a finding.
What is known about each separately
For ipamorelin: one randomised controlled trial in 117 patients, which found no significant difference from placebo on its efficacy endpoints [Beck 2014]; one dose-escalation study in 40 healthy men characterising a single growth hormone pulse with a two-hour half-life [Gobburu 1999]; and a larger trial of 320 patients that completed in 2014 and has never reported [NCT01280344].
For CJC-1295, this database holds no primary research, because its search is for ipamorelin. That absence is a limit of this site rather than a statement about the compound, and it is stated plainly for that reason. A 2020 review discussing this class as a whole concludes that clinical efficacy data largely remain lacking[Sinha 2020].
A shared product-quality problem
The 2019 analysis of preparations seized by Danish customs identified glycine-extended analogues of ipamorelin, GHRP-2, GHRP-6 and modified GRF (1-29) — the same compound sold as CJC-1295 without DAC[Gajda 2019]. An earlier study found Gly-ipamorelin in black-market products and confirmed it by custom synthesis [Krug 2018]. Whatever is true of either compound in research, material sold under these names has repeatedly turned out to be something slightly different.
What this page will not tell you
It contains no dosing, no ratios, no timing and no protocol for either compound alone or together. There is no validated dose of ipamorelin for any purpose — the two trials that tested one produced a null result and an unreported result respectively. The comparison tool sets ipamorelin against several other compounds on the same verified fields.
References
- Raun K, Hansen BS, Johansen NL et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. PubMed 9849822 · doi:10.1530/eje.0.1390552[Animal, grade C]
- Gobburu JV, Agersø H, Jusko WJ et al. (1999). Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. PubMed 10496658 · doi:10.1023/a:1018955126402[Human, grade B]
- Beck DE, Sweeney WB, McCarter MD et al. (2014). 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. PubMed 25331030 · doi:10.1007/s00384-014-2030-8[Human, grade A]
- Gajda PM, Holm NB, Hoej LJ et al. (2019). Glycine-modified growth hormone secretagogues identified in seized doping material. Drug Test Anal. PubMed 30136411 · doi:10.1002/dta.2489[Analytical, grade D]
- Krug O, Thomas A, Malerød-Fjeld H et al. (2018). Analysis of new growth promoting black market products. Growth Horm IGF Res. PubMed 29864719 · doi:10.1016/j.ghir.2018.05.001[Analytical, grade D]
- Sinha DK, Balasubramanian A, Tatem AJ et al. (2020). Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Transl Androl Urol. PubMed 32257855 · doi:10.21037/tau.2019.11.30[Review, grade R]
- PubChem, National Library of Medicine. Ipamorelin (CID 9831659). Source[retrieved 2026-11-11]
- U.S. Food and Drug Administration, openFDA. openFDA Drugs@FDA and NDC directory queries for ipamorelin. Source[retrieved 2026-11-11]
- ClinicalTrials.gov, U.S. National Library of Medicine (2011-04). Phase II Double-Blind Placebo-Controlled Dose Finding Study to Evaluate Safety/Efficacy of Ipamorelin Compared to Placebo for Recovery of Gastrointestinal Function Following Bowel Resection (NCT01280344). Source[retrieved 2026-11-11]