Educational reference. Research use only.
Ipamorelin / CJC-1295: Mechanism, Research, and Regulatory Status
Ipamorelin / CJC-1295 is a research blend of two growth hormone secretagogues: ipamorelin, a ghrelin-receptor pentapeptide (CAS 170851-70-4, 711.85 Da), and CJC-1295 without DAC, a modified GHRH(1-29) analog (3367.97 Da). The blend itself has no published trials; 2 human studies examined the components separately. Neither component is approved for human use.
Last reviewed 2026-09-29
What is Ipamorelin / CJC-1295?
Ipamorelin / CJC-1295 key facts
Ipamorelin / CJC-1295 combines two peptides that act at different points of the growth hormone axis. Ipamorelin is the pentapeptide Aib-His-D-2Nal-D-Phe-Lys-NH2, CAS number 170851-70-4, molecular weight 711.85 Da, and acts at the ghrelin receptor GHS-R1a; Raun and colleagues described ipamorelin in 1998 as the first selective growth hormone secretagogue. CJC-1295 without DAC, also called mod-GRF(1-29), is a modified growth hormone-releasing hormone (1-29) analog of 3367.97 Da that acts at the GHRH receptor. No study of the combination has been published. For ipamorelin, a Phase 2 trial in postoperative ileus (Beck and colleagues, International Journal of Colorectal Disease, 2014, n=114) found no significant difference from placebo on its efficacy endpoints. For CJC-1295, a 2006 study of the long-acting form by Ionescu and Frohman reported that pulsatile growth hormone secretion persisted during continuous stimulation in healthy men. Ipamorelin and CJC-1295 are investigational, are prohibited by WADA under S2, and are supplied for research use only.
How does Ipamorelin / CJC-1295 work?
This combination targets two distinct but synergistic nodes in the growth hormone (GH) axis. CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH(1–29)) carrying four amino acid substitutions that make it resistant to the enzyme DPP-4, which extends its half-life. The non-DAC version (also known as mod-GRF(1–29)) has a half-life of ~30 minutes.
The DAC (Drug Affinity Complex) version binds covalently to plasma albumin through a maleimide linker, giving it a half-life of approximately 6–8 days. CJC-1295 acts on the GHRH receptor (GHRHR) on pituitary somatotrophs, the pituitary cells that release GH, and increases the size of each GH pulse. Ipamorelin is a selective growth hormone secretagogue pentapeptide.
It acts as a partial agonist at the ghrelin receptor (GHS-R1a) and increases how often GH pulses occur, working through a different intracellular pathway (Gq/PKC rather than Gs/cAMP). Ipamorelin is also highly selective for that receptor: it does not appreciably stimulate ACTH, cortisol, or aldosterone release, unlike older GH secretagogues (GHRP-6, GHRP-2). Combining CJC-1295 (pulse size) and ipamorelin (pulse frequency) produces GH release patterns that more closely mimic youthful physiological pulsatility.
In preclinical and small human studies, the pair raised GH and IGF-1 more than either agent alone.
What has research on Ipamorelin / CJC-1295 found?
What published peer-reviewed research and preclinical studies have established about Ipamorelin / CJC-1295:
- 01Combination targets two independent GH axis nodes: CJC-1295 (GHRH receptor) amplifies pulse amplitude; ipamorelin (GHS-R1a/ghrelin receptor) increases pulse frequency
- 02Ipamorelin is highly selective, with minimal stimulation of ACTH, cortisol, or prolactin compared with older GH secretagogues (GHRP-6, hexarelin), confirmed in Phase 1 data
- 03CJC-1295 with DAC: half-life of roughly 6–8 days via covalent albumin binding
- 04Beck et al., 2014 (Phase 2, n=114 analysed): in post-operative ileus after bowel resection, ipamorelin was well tolerated but did not differ significantly from placebo on the key efficacy endpoint (median time to first tolerated meal 25.3 vs 32.6 h, p=0.15)
- 05CJC-1295 in healthy men (Ionescu & Frohman, JCEM 2006): one week after a single dose, GH pulse frequency and magnitude were unaltered while trough GH rose 7.5-fold, mean GH 46% and IGF-1 45%
- 06Preclinical bone growth data: ipamorelin dose-dependently increased tibial longitudinal bone growth rate in adult female rats over 15 days (Johansen et al., 1999)
- 07The combination is studied in somatotroph-axis research; preclinical data report greater IGF-1 elevation than with either peptide alone
Which studies have examined Ipamorelin / CJC-1295?
Ipamorelin for post-operative ileus (Phase 2 RCT)
Phase 2 RCT · 2014Well tolerated; no significant difference vs placebo on the key or secondary efficacy endpoints (median time to first tolerated meal 25.3 vs 32.6 h, p=0.15)
CJC-1295 and GH pulsatility in healthy men
Clinical pharmacology · 2006GH secretion rose with pulsatility preserved: pulse frequency and magnitude unaltered, trough GH up 7.5-fold, mean GH up 46% and IGF-1 up 45%; no difference between the two doses tested
Ipamorelin bone growth: preclinical (adult female rats)
Preclinical · 1999Longitudinal bone growth rate rose dose-dependently from 42 μm/day (vehicle) to 44, 50 and 52 μm/day (p<0.0001), with dose-dependent body weight gain; total IGF-I, IGFBPs and bone turnover markers were unchanged
Frequently asked questions about Ipamorelin / CJC-1295
What is the difference between CJC-1295 with DAC and without DAC (mod-GRF 1-29)?+
CJC-1295 without DAC (also called Modified GRF 1-29 or mod-GRF 1-29) has a half-life of approximately 25–30 minutes, short enough to resemble the natural pulsatile GHRH pattern. CJC-1295 with DAC contains a maleimide-modified lysine that forms a covalent bond with plasma albumin, extending half-life to 6–8 days. The DAC version therefore produces a more sustained, blunted GH elevation, while the non-DAC form produces discrete pulses.
Why is ipamorelin preferred over GHRP-6 or GHRP-2 in research?+
Older GH secretagogues like GHRP-6 and GHRP-2 stimulate GH release but also elevate ACTH, cortisol, aldosterone, and prolactin. Those are confounding factors in many research protocols, and they are associated with increased appetite (GHRP-6's notable hunger effect via ghrelin signaling in the hypothalamus). Ipamorelin is highly selective for GHS-R1a and does not affect those axes, which makes it the preferred choice for GH-specific research and allows cleaner mechanistic attribution of observed effects.
How does the CJC-1295 + ipamorelin combination synergize?+
The two peptides act on separate but complementary receptor systems. CJC-1295 (GHRHR agonist) amplifies the magnitude of each GH pulse from the pituitary somatotroph. Ipamorelin (GHS-R1a agonist) increases the frequency of GH pulses and may also independently sensitize somatotrophs. In preclinical models the combination produces substantially greater IGF-1 elevation than either agent alone, closely mimicking juvenile GH secretion profiles.
How should these peptides be stored?+
Both ipamorelin and CJC-1295 in lyophilized form: −20°C in sealed, desiccated vials protected from light. Lyophilized peptides are stable for 24+ months under proper conditions. Avoid freeze-thaw cycling. Keep silica desiccant packets with vials if possible. Room temperature stability is limited (days to weeks); always return to −20°C between uses.
Is this combination WADA prohibited?+
Yes. Both ipamorelin (GH secretagogue) and CJC-1295 (GHRH analog/GH-releasing factor) are prohibited under WADA S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics). This applies in all competitive sport contexts and during training periods. For non-sport research contexts, the compounds are not scheduled controlled substances in most jurisdictions but lack regulatory approval for therapeutic use.
What endpoints are most relevant for studying this combination?+
Key research endpoints include: serum IGF-1 (most reliable surrogate for integrated GH secretion), IGFBP-3, GH pulse sampling (requires frequent blood draws), lean body mass and fat mass by DEXA, fasting insulin/glucose (for insulin resistance monitoring), and bone mineral density in longer-duration studies. GH stimulation testing before and after treatment can document whether the pituitary axis is appropriately upregulated without desensitization.
Can ipamorelin/CJC-1295 research be conducted in elderly populations?+
Preclinical and small human studies specifically in GH-deficient older adults show that GH secretagogues can restore more youthful GH pulsatility with fewer side effects than direct GH replacement. The elderly population is a key research demographic given age-related GH decline (somatopause). Relevant monitoring: IGF-1 should not be driven above age-specific reference ranges; glucose tolerance should be tracked, as GH-induced insulin resistance may be more pronounced in older adults.
References & sources
Every citation below was resolved against its primary source before publication. Each PMID was checked against its PubMed record and each DOI through doi.org. Follow any link to read the paper at the publisher rather than taking our summary on trust.
- [1]Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology. 1998. PMID: 9849822 DOI: 10.1530/eje.0.1390552
- [2]Johansen PB, Nowak J, Skjaerbaek C, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Hormone & IGF Research. 1999. PMID: 10373343 DOI: 10.1054/ghir.1999.9998
- [3]Beck DE, Sweeney WB, McCarter MD. Prospective, 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. 2014. PMID: 25331030 DOI: 10.1007/s00384-014-2030-8
- [4]Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism. 2006. PMID: 17018654 DOI: 10.1210/jc.2006-1702
- [5]Teichman SL, Neale A, Lawrence B, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology and Metabolism. 2006. PMID: 16352683 DOI: 10.1210/jc.2005-1536
- [6]Smith RG. Development of growth hormone secretagogues. Endocrine Reviews. 2005. PMID: 15814848 DOI: 10.1210/er.2004-0019
- [7]Kojima M, Hosoda H, Date Y, et al. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999. PMID: 10604470 DOI: 10.1038/45230
Where this data comes from
- Citations & trial data: PubMed (NCBI, U.S. National Library of Medicine), Crossref and ClinicalTrials.gov.
- Chemical identity: PubChem and UniProt. Where sources conflicted, the disputed value is omitted rather than guessed.
- Regulatory status: U.S. FDA publications and, where applicable, the WADA Prohibited List. Compounding status changes often, so check FDA directly before relying on it.
- Purity, form and storage are handling and supplier conventions, not literature-derived values. Confirm against the lot-specific certificate of analysis. General handling is covered in the storage and stability guide.
Content last reviewed 2026-09-29. Compiled by Veridian Research from the primary literature. This page is an educational reference for laboratory researchers. It is not medical advice, and it describes no human use.
Is Ipamorelin / CJC-1295 approved for human use?
Both ipamorelin and CJC-1295 are investigational compounds with no approved therapeutic use. WADA prohibits both under S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics). For research purposes only.
Research-use-only material
Specifications and certificate of analysis
Ipamorelin / CJC-1295 is stocked as a research reagent. Analytical documentation, covering identity, purity and the lot-specific certificate of analysis, is published in the certificate library.