# CJC-1295 Ipamorelin: An Indexed Almanac of the Growth-Hormone-Secretagogue Literature

> CJC-1295 ipamorelin research: 22 indexed findings across six species covering two receptor arms, pharmacokinetics, bone density, sleep, and GI motility. A peer-reviewed literature digest.

## What the CJC-1295 Ipamorelin Literature Has Established

CJC-1295 ipamorelin is a two-component growth-hormone secretagogue blend studied across more than two decades of peer-reviewed endocrinology research. CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) that binds the GHRH receptor on anterior pituitary somatotrophs. Ipamorelin is a selective synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that binds the ghrelin receptor (GHS-R1a). The two act on distinct receptor arms — the GHRH axis and the ghrelin axis — and their combination produces supraadditive GH release in preclinical and human models.[13]

In a published Phase I/II-context human study, CJC-1295 at 60–90 µg/kg subcutaneous increased mean GH by 46% and IGF-1 by 45% one week post-dose, with pulsatile GH secretion preserved and basal GH elevated 7.5-fold.[1] Ipamorelin, described in the first selectivity study as the first selective growth hormone secretagogue, did not elevate ACTH, cortisol, FSH, LH, prolactin, or TSH even at doses more than 200-fold above its GH-release ED50 in rat and swine models.[3]

Neither CJC-1295 nor ipamorelin holds FDA approval for any human indication. Both appear on the WADA Prohibited List (Section S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics).

## The CJC-1295 Ipamorelin Blend: Synergistic Growth Hormone Secretagogues

The rationale for combining CJC-1295 and ipamorelin rests on two independent receptor axes that produce greater GH output together than either compound achieves alone. In a cross-species analysis covering human, rat, swine, bovine, and canine models, a near-threshold GHS dose combined with a maximally effective GHRH dose produced supraadditive GH release.[13]

## What is CJC-1295 Ipamorelin Good For?

The CJC-1295/ipamorelin blend has been studied in preclinical models for: dose-dependent increases in longitudinal bone growth rate (42 to 52 µm/day over 15 days in adult female rats, p<0.0001 [4]); 4-fold increases in periosteal bone formation rate [8]; increased bone mineral content [9]; and restored gastrointestinal motility in postoperative ileus models via GHS-R1a agonism [10]. In human models, ghrelin enhanced slow-wave sleep in human subjects [12].

## What Are CJC-1295 and Ipamorelin?

CJC-1295 is a tetrasubstituted synthetic analog of human GHRH(1-29) with a maleimidopropionamide-lysine Drug Affinity Complex (DAC) appended at the C-terminus, extending plasma half-life to approximately 6–8 days.[2][16] Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2, MW 711.9 Da) that selectively binds GHS-R1a.[7]

## Synergistic Mechanism

Three synergistic sub-mechanisms were confirmed across five species: ghrelin/GHS-R1a agonism (a) directly stimulates pituitary GH release, (b) antagonizes somatostatin at the pituitary, and (c) induces additional hypothalamic GHRH secretion.[13]

## References

[1] Ionescu M, Frohman LA. Pulsatile secretion of GH persists during CJC-1295 stimulation. J Clin Endocrinol Metab. 2006;91(12):4792-4797. https://pubmed.ncbi.nlm.nih.gov/17018654/
[2] Jetté L, et al. hGRF1-29-albumin bioconjugates: CJC-1295. Endocrinology. 2005;146(7):3052-3058. https://pubmed.ncbi.nlm.nih.gov/15817669/
[3] Raun K, et al. Ipamorelin, the first selective GH secretagogue. Eur J Endocrinol. 1998;139(5):552-561. https://pubmed.ncbi.nlm.nih.gov/9849822/
[4] Johansen PB, et al. Ipamorelin induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106-113. https://pubmed.ncbi.nlm.nih.gov/10373343/
[7] Johansen PB, et al. Pharmacokinetics of ipamorelin. Xenobiotica. 1998;28(12):1243-1252. https://pubmed.ncbi.nlm.nih.gov/9879640/
[8] Andersen NB, et al. Ipamorelin counteracts glucocorticoid-induced bone loss. Growth Horm IGF Res. 2001;11(5):266-272. https://pubmed.ncbi.nlm.nih.gov/11735244/
[9] Svensson J, et al. Ipamorelin increases bone mineral content in rats. J Endocrinol. 2000;165(3):569-577. https://pubmed.ncbi.nlm.nih.gov/10828840/
[10] Venkova K, et al. Ipamorelin in rodent model of postoperative ileus. J Pharmacol Exp Ther. 2009;329(3):1110-1116. https://pubmed.ncbi.nlm.nih.gov/19289567/
[12] Weikel JC, et al. Ghrelin promotes slow-wave sleep in humans. Am J Physiol Endocrinol Metab. 2003;284(2):E407-E415. https://pubmed.ncbi.nlm.nih.gov/12388174/
[13] Farhy LS, Veldhuis JD. Amplifying actions of ghrelin on pulsatile GH secretion. Am J Physiol Regul Integr Comp Physiol. 2005;288(5):R1649-R1663. https://pubmed.ncbi.nlm.nih.gov/15718392/
[16] Memdouh S, et al. Advances in detection of GHRH synthetic analogs. Drug Test Anal. 2021;13(7):1233-1247. https://pubmed.ncbi.nlm.nih.gov/34665524/
[18] Spooner LM, Olin JL. Tesamorelin for HIV-associated lipodystrophy. Ann Pharmacother. 2012;46(2):240-247. https://pubmed.ncbi.nlm.nih.gov/22298602/

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Twenty-two studies across six species, indexed as a folk-almanac of the CJC-1295 ipamorelin literature — no clinic behind the cordel, no vendor behind the broadside.