CJC-1295 is a synthetic 29-amino-acid analog of growth hormone-releasing hormone (GHRH) that has been researched for its effects on the growth hormone (GH) / insulin-like growth factor 1 (IGF-1) axis — the central hormonal pathway regulating growth, body composition, and metabolic signaling.
Developed in the early 2000s by ConjuChem Biotechnologies, CJC-1295 was engineered to solve a practical problem in GHRH research: natural GHRH is cleared from circulation within minutes, making sustained study of GHRH-driven GH release difficult. CJC-1295 introduced amino-acid substitutions that resist enzymatic degradation — and in its best-known form, a chemical modification that tethers the peptide to serum albumin, extending its presence in the body from minutes to roughly a week.
What Is CJC-1295?
CJC-1295 is based on GHRH(1-29) — the shortest fully active fragment of the 44-amino-acid hypothalamic hormone that commands the pituitary gland to release growth hormone. Four amino-acid substitutions (at positions 2, 8, 15, and 27) make the molecule resistant to DPP-IV and other proteases that rapidly destroy natural GHRH.
Two distinct research forms exist, and confusing them is the most common error in discussions of this compound:
- CJC-1295 DAC (Drug Affinity Complex) — the original ConjuChem design, carrying a maleimide group that covalently binds to circulating serum albumin after administration. This albumin “hitchhiking” produced a reported half-life of roughly 6–8 days, with elevated IGF-1 persisting for up to two weeks after a single dose in early human studies.
- CJC-1295 without DAC — often called Mod GRF(1-29) or tetrasubstituted GHRF(1-29). This is the same stabilized 29-amino-acid peptide without the albumin-binding modification, and its half-life is measured in minutes — a fundamentally different pharmacokinetic profile despite the shared name.
Research has investigated CJC-1295 for its relationship with pituitary GH release, circulating IGF-1 levels, GH pulsatility, body composition, sleep architecture, and synergistic GH release when combined with ghrelin-receptor agonists.
How Does CJC-1295 Work?
CJC-1295 has been studied as an agonist of the GHRH receptor (GHRHR) on somatotroph cells of the anterior pituitary. Researchers have investigated its relationship with:
- GHRH receptor activation — binding GHRHR on pituitary somatotrophs triggers intracellular cAMP signaling, the canonical pathway by which the hypothalamus commands GH release
- Pulsatile GH secretion — unlike continuous GH infusion, GHRH-driven release preserves the body’s natural episodic GH pulses; a 2006 human study reported that pulsatile GH secretion persisted during sustained CJC-1295 stimulation
- IGF-1 elevation — GH released under CJC-1295 stimulation acts on the liver to increase IGF-1 production; early human research reported dose-dependent IGF-1 increases lasting 9–11 days after a single administration of the DAC form
- Albumin conjugation (DAC form) — the maleimide modification binds endogenous serum albumin, shielding the peptide from renal clearance and enzymatic degradation and extending its circulating half-life to roughly a week
- Synergy with ghrelin-receptor agonists — GHRH and ghrelin-pathway agonists (such as ipamorelin and other growth hormone secretagogues) act through distinct receptors, and decades of research have documented that the two pathways release GH synergistically — together producing more GH than the sum of either alone
- Negative-feedback preservation — because CJC-1295 works through the pituitary rather than supplying GH directly, the body’s somatostatin-mediated feedback loops remain engaged, a distinction researchers have studied as relevant to the physiology of GH-axis stimulation
Key Takeaway: CJC-1295 is particularly interesting to researchers because it extends GHRH biology from a minutes-long signal into a days-long one — allowing sustained study of pituitary-driven GH release while preserving the body’s natural pulsatile pattern — though the human evidence base is limited to short early-phase studies.
Potential Benefits of CJC-1295
GH Axis & IGF-1 Research
The GH/IGF-1 axis is the most directly studied area of CJC-1295 research.
In the landmark 2006 study published in the Journal of Clinical Endocrinology & Metabolism, researchers administered single injections of CJC-1295 (DAC form) to healthy adults and reported dose-dependent increases in mean plasma GH — roughly 2- to 10-fold elevations persisting for six or more days — alongside IGF-1 increases lasting 9–11 days. The compound was reported to be well tolerated in that short study.
A companion 2006 study examined the pattern of GH release, reporting that pulsatile GH secretion persisted during continuous CJC-1295 stimulation — the pituitary continued releasing GH in its natural episodic bursts rather than switching to flat, continuous output. Researchers have treated this as a meaningful physiological distinction from direct GH administration.
Body Composition Research
Because the GH/IGF-1 axis regulates lean mass, adipose tissue, and protein metabolism, CJC-1295 has been discussed in the context of body-composition research.
The early human studies were too short to evaluate body-composition outcomes, and no published trial has tested CJC-1295 for changes in muscle mass, fat mass, or related endpoints. Animal research on GHRH-axis stimulation provides the mechanistic rationale, but direct evidence for body-composition effects of CJC-1295 in any species remains essentially absent from the published literature — an important gap that is often glossed over.
Sleep Architecture Research
GH release is tightly coupled to slow-wave (deep) sleep, with the largest daily GH pulse occurring shortly after sleep onset — and GHRH itself has been studied as a sleep-regulatory signal independent of its pituitary role.
While CJC-1295 specifically has not been the subject of published sleep-architecture studies, the GHRH pathway it activates is an established subject of sleep research: GHRH administration has been reported to promote non-REM sleep in animal and human studies. This positions CJC-1295 within a broader research conversation about the GHRH–sleep–GH triangle, even though compound-specific sleep data do not exist.
Combination (GHRH + Ghrelin-Agonist) Synergy Research
One of the most replicated findings in GH-axis research is the synergy between GHRH-pathway and ghrelin-pathway stimulation. Growth hormone secretagogues acting on the ghrelin receptor (GHS-R1a) — including ipamorelin — release GH through a separate receptor system, and co-stimulation has been reported to produce supra-additive GH release in both animal and human studies.
This synergy is a property of the two pathways, documented across many compound pairings since the 1980s, and it is why CJC-1295 and ipamorelin are so frequently discussed together in research contexts. The combined protocols themselves have not been tested in formal clinical trials.
It is important to distinguish these laboratory and early-phase findings from demonstrated outcomes in longer or larger studies.
CJC-1295 vs. Other Peptides
CJC-1295 has a different research profile from peptides such as BPC-157, TB-500, and GHK-Cu, which are researched for tissue repair, cell migration, and skin biology — not hormonal axis signaling.
Ipamorelin is CJC-1295’s closest research counterpart: a selective ghrelin-receptor agonist that also stimulates pituitary GH release, but through the GHS-R1a receptor rather than the GHRH receptor. Researchers study the two as complementary tools for probing the two natural GH-release pathways — hypothalamic (GHRH) and gastric/hypothalamic (ghrelin) — and their documented synergy is one of the most replicated phenomena in GH-axis literature.
BPC-157 and TB-500 are studied for local tissue-repair processes (tendon, gut, wound models) and do not act on the GH axis, making their research questions entirely separate from CJC-1295’s endocrine focus.
CJC-1295’s research is more closely associated with:
GHRH Receptor Agonism → Pulsatile GH Release → IGF-1 Signaling → Growth & Metabolic Axis Biology
What sets CJC-1295 apart is its pharmacokinetic engineering: it took a hormone fragment with a minutes-long lifespan and — in the DAC form — made it a week-long research tool for studying sustained, physiologically patterned GH-axis activation.
Regulatory Status
CJC-1295’s regulatory position is worth stating plainly:
- CJC-1295 is not FDA approved for any indication, and no CJC-1295 drug product has been approved anywhere as a medicine.
- ConjuChem’s clinical development program investigated CJC-1295 in early-phase human studies in the mid-2000s and was subsequently discontinued — the compound never advanced to late-stage trials.
- CJC-1295 has appeared on anti-doping watch lists in sports contexts, and athletes should check current anti-doping rules, as peptide categories are broad and updated regularly.
Regulatory developments do not change the underlying evidence base: the human data consists of short early-phase studies only.
What Does the Research Say?
The CJC-1295 literature provides a basis for continued research into sustained GHRH-receptor stimulation and its effects on pulsatile GH release and IGF-1 levels — and the DAC albumin-binding design remains a cited example of half-life-extension engineering in peptide research.
However, the evidence gaps are substantial and should be understood clearly:
First, the human evidence consists of a small number of short studies from the mid-2000s — single-dose and brief multiple-dose pharmacology in healthy adults. No long-term human study of CJC-1295 has been published.
Second, no published study has evaluated CJC-1295 for body-composition, performance, or disease-related endpoints. The compound’s reputation in non-scientific discussions runs far ahead of what was actually measured.
Third, the DAC and non-DAC forms are pharmacokinetically different drugs sharing a name. Findings from the DAC form (week-long activity) do not transfer to the non-DAC/Mod GRF(1-29) form (minutes-long activity), and much informal discussion conflates the two.
Short pharmacology studies of a discontinued compound are not the same as an established evidence base, and enthusiasm around CJC-1295 runs well ahead of what the literature supports.
Frequently Asked Questions
What is CJC-1295?
CJC-1295 is a synthetic 29-amino-acid analog of growth hormone-releasing hormone (GHRH) developed by ConjuChem in the early 2000s. It has been researched for its ability to stimulate pituitary growth hormone release and elevate IGF-1 through the GHRH receptor.
What is the difference between CJC-1295 DAC and non-DAC?
CJC-1295 DAC (Drug Affinity Complex) carries a maleimide modification that binds serum albumin, extending its half-life to roughly a week. The non-DAC form (often called Mod GRF 1-29) is the same stabilized peptide without the albumin-binding group, with a half-life measured in minutes. They are pharmacokinetically different despite the shared name.
What does the research show?
Early human studies (2006) reported that single doses of the DAC form increased mean GH levels 2- to 10-fold for six or more days and elevated IGF-1 for 9–11 days, with pulsatile GH secretion preserved. No long-term studies and no body-composition or disease-endpoint trials have been published.
How is CJC-1295 different from ipamorelin?
Both stimulate pituitary GH release, but through different receptors: CJC-1295 activates the GHRH receptor, while ipamorelin activates the ghrelin receptor (GHS-R1a). Research has documented that the two pathways release GH synergistically when studied together.
Is CJC-1295 FDA approved?
No. CJC-1295 is not FDA approved for any indication, and no CJC-1295 drug product has been approved anywhere. ConjuChem’s development program was discontinued after early-phase studies.
Has CJC-1295 been tested in humans?
Yes, but only in short early-phase pharmacology studies in the mid-2000s involving healthy adults. No long-term human trials have been conducted.
The Bottom Line
CJC-1295 is a notable case study in peptide engineering applied to endocrine research — a protease-resistant GHRH analog that, in its DAC form, extended a minutes-long hormonal signal into a week-long one, producing sustained, pulsatile GH release and multi-day IGF-1 elevation in early human studies.
The pharmacology findings are genuinely interesting, particularly the preservation of natural GH pulsatility during continuous stimulation. But the program was discontinued after early-phase work, no long-term or outcome-oriented studies exist, and the DAC/non-DAC distinction is routinely blurred in non-scientific discussion.
For researchers interested in GH-axis biology, GHRH-receptor pharmacology, and half-life-extension strategies in peptide design, CJC-1295 remains a relevant — if historically bounded — area of the literature.
Explore CJC-1295
Learn more about CJC-1295 and explore our research-focused CJC-1295 peptide at Vonox Labs: https://vonoxlabs.com/product/cjc-1295-no-dac-ipamorelin/
Research. Test. Learn.
Ver materiales de investigación: Tienda VONOX Labs
Research Use Only: Vonox Labs products are intended strictly for laboratory and research purposes and are not intended for human or veterinary consumption. This information is provided for educational purposes only and is not medical advice.
Scientific References
- Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. 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. J Clin Endocrinol Metab. 2006;91(3):799-805. (Single injections of the DAC form in healthy adults; dose-dependent GH increases for 6+ days and IGF-1 elevation for 9–11 days.)
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792-7. (GH pulsatility preserved during sustained CJC-1295 stimulation in healthy adults.)
- Jette L, Leger R, Thibaudeau K, et al. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology. 2005;146(7):3052-8. (Preclinical characterization of the albumin-binding DAC design.)
- Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1998;54(12):1316-29. (Review covering GHRH/GHRP synergy in GH release — the pathway interaction relevant to CJC-1295 + ghrelin-agonist research.)
Leave a Reply