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CJC-1295

Also known as: GRF 1-29 (CJC1295)

Quick answer

CJC-1295 is a long-acting growth hormone-releasing hormone (GHRH) analog studied in preclinical research for its capacity to stimulate growth hormone (GH) and insulin-like growth factor I (IGF-I) secretion. It is a research compound not approved by the FDA for human use.

What is CJC-1295?

CJC-1295 is a synthetic peptide designed as a long-acting analog of growth hormone-releasing hormone (GHRH). It functions to stimulate the pituitary gland to release growth hormone (GH), which subsequently elevates levels of insulin-like growth factor I (IGF-I), both critical hormones involved in tissue growth and regeneration. Its extended half-life distinguishes it from native GHRH, allowing for sustained hormone release and prolonged biological effects.

The compound was developed to overcome the short half-life limitations of natural GHRH, enabling more practical research into the modulation of the GH/IGF-I axis. CJC-1295’s chemical structure (molecular formula C165H269N47O46) and molecular weight (3647.2 g/mol) reflect its peptide nature, with modifications that enhance its pharmacokinetic stability.

In preclinical and clinical research contexts, CJC-1295 is investigated for its potential to support tissue repair, recovery, and growth processes by maintaining elevated GH and IGF-I levels over extended periods. Its use remains confined to laboratory and experimental settings, with no regulatory approval for clinical or therapeutic use.

Researchers study CJC-1295 to better understand long-acting GH secretagogues and their impact on endocrine pathways, with implications for regenerative medicine, orthopaedics, and sports science research.

Key Benefits & Mechanisms

  • Sustained Growth Hormone SecretionResearch shows that CJC-1295 significantly prolongs the secretion of growth hormone (GH) compared to native GHRH. This sustained GH release is important in experimental models studying tissue growth and metabolic regulation, providing a tool to explore extended GH axis activation.
  • Elevated Insulin-Like Growth Factor I LevelsBy stimulating GH secretion, CJC-1295 indirectly increases circulating insulin-like growth factor I (IGF-I) levels, a key mediator of anabolic and regenerative processes. This effect has been observed to persist for days following administration in research subjects.
  • Potential Support for Tissue RegenerationPreclinical studies suggest that the prolonged activation of the GH/IGF-I axis by CJC-1295 may support cellular proliferation and tissue repair mechanisms. This property is of interest in musculoskeletal and orthopaedic research, where enhancing recovery pathways is a focus.
  • Pharmacokinetic AdvantagesCJC-1295’s molecular modifications confer an extended half-life, allowing less frequent dosing in experimental protocols. This pharmacokinetic profile facilitates sustained biological activity, making it a valuable compound for research into long-term GH modulation.
  • Research Tool for Endocrine ModulationAs a research peptide, CJC-1295 serves as a model compound to study the effects of prolonged GHRH receptor activation and downstream signaling. This aids in elucidating mechanisms of hormone regulation and potential therapeutic targets within the GH/IGF-I axis.

Mechanism of action

CJC-1295 acts as a long-acting analog of growth hormone-releasing hormone (GHRH), binding to GHRH receptors on pituitary somatotroph cells to stimulate the secretion of growth hormone (GH). Unlike native GHRH, CJC-1295 has been chemically modified to resist enzymatic degradation and extend its half-life, resulting in sustained receptor activation. The increased GH secretion leads to elevated plasma levels of insulin-like growth factor I (IGF-I), produced primarily in the liver, which mediates many anabolic and regenerative effects. This prolonged stimulation of the GH/IGF-I axis supports cellular growth, tissue repair, and metabolic regulation in experimental models. The pharmacokinetic profile of CJC-1295 enables dose-dependent, extended elevation of these hormones, which is valuable for research into endocrine modulation and recovery processes.

Research Summary

Research on CJC-1295 has primarily focused on its pharmacokinetic and pharmacodynamic properties in healthy adults. In the 2006 study "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," investigators conducted randomized, placebo-controlled trials demonstrating that single subcutaneous doses of CJC-1295 produced dose-dependent increases in GH levels lasting six days or more and elevated IGF-I levels for up to 9–11 days. Multiple dosing regimens sustained IGF-I elevations for up to 28 days, with a half-life estimated between 5.8 and 8.1 days, and no serious adverse effects were reported. This study supports CJC-1295’s capacity for prolonged GH/IGF-I axis activation in humans under controlled research conditions. More recent reviews in 2026, such as "Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions," contextualize CJC-1295 among growth hormone secretagogues studied for their potential to activate IGF-1 signaling and satellite cell repair in musculoskeletal research. These analyses emphasize the peptide’s role in experimental regenerative medicine and highlight the need for further clinical investigation. Similarly, the 2026 narrative review "Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians" discusses CJC-1295 alongside other peptides, noting its investigational use in enhancing growth hormone release and recovery. While preclinical data are promising, clinical evidence remains limited, underscoring the importance of rigorous research protocols and safety assessments in future studies.

Dosing in Research Literature

Research studies investigating CJC-1295 have employed a range of dosing protocols, primarily in the context of controlled clinical trials with healthy adult volunteers. Single subcutaneous doses have varied across ascending dose ranges, with some studies administering doses approximately within the range of 30 to 60 micrograms per kilogram of body weight. These doses produced sustained elevations of GH and IGF-I lasting several days to weeks.

Multiple dosing regimens have included weekly or biweekly subcutaneous injections, with cumulative effects observed on IGF-I levels persisting for up to 28 days post-administration. Despite these documented protocols, precise dosing guidelines remain undetermined, and all dosing information is confined to experimental research contexts. No established therapeutic dosing or clinical usage parameters exist, and safety and efficacy profiles require further investigation.

The figures above describe doses reported in published or preclinical research, provided for context only. This is not medical advice or a dosing recommendation, and these compounds are not approved for human use.

Common Stacks

Ipamorelin Ipamorelin is often researched in combination with CJC-1295 to synergistically stimulate growth hormone release via complementary mechanisms, potentially enhancing the amplitude and duration of GH secretion in experimental models. Tesamorelin Tesamorelin, another growth hormone-releasing peptide, is studied alongside CJC-1295 to compare pharmacodynamic profiles and explore combined effects on the GH/IGF-I axis relevant to tissue regeneration research. GHRP-6 GHRP-6 is combined with CJC-1295 in research settings to investigate additive or synergistic effects on pituitary GH release, facilitating a broader understanding of growth hormone secretagogues in preclinical studies.

Frequently asked questions about CJC-1295

Is CJC-1295 approved by the FDA for clinical use?

No, CJC-1295 is not approved by the U.S. Food and Drug Administration (FDA) for any clinical or therapeutic use. It is classified strictly as a research peptide and is intended solely for laboratory and experimental applications.

What is the primary research focus for CJC-1295?

Research on CJC-1295 focuses on its ability to act as a long-acting growth hormone-releasing hormone analog, stimulating sustained secretion of growth hormone and subsequent increases in insulin-like growth factor I. These effects are studied in the context of tissue growth, regeneration, and endocrine modulation.

How does CJC-1295 function mechanistically?

CJC-1295 binds to growth hormone-releasing hormone receptors on pituitary cells, triggering prolonged growth hormone secretion. Its molecular modifications extend its half-life, enabling sustained activation of the GH/IGF-I axis, which supports anabolic and regenerative processes in experimental models.

Can CJC-1295 be combined with other peptides in research?

Yes, CJC-1295 is frequently studied in combination with other growth hormone secretagogues such as ipamorelin, tesamorelin, and GHRP-6 to investigate synergistic effects on growth hormone release and to better understand complex endocrine interactions in preclinical research.

What are the recommended storage and handling conditions for CJC-1295?

As a research peptide, CJC-1295 should be stored according to manufacturer guidelines, typically requiring refrigeration at controlled temperatures to maintain stability. Handling should be conducted with appropriate laboratory safety measures, and the compound should be used only in authorized research settings.

Are there established dosing protocols for CJC-1295 in research?

Dosing protocols in research vary, with studies employing single or multiple subcutaneous doses ranging approximately from 30 to 60 micrograms per kilogram. These protocols are experimental, and no standardized dosing recommendations exist outside of controlled research environments.

What safety information is available for CJC-1295?

Clinical trials in healthy adults have reported that CJC-1295 is generally well tolerated at studied doses, with no serious adverse events. However, comprehensive safety profiles require further study, and its use remains restricted to research contexts only.

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Legal & research status: Research use only — not approved by the FDA for human use. Sold and discussed for laboratory and research use only, not for human consumption.

Research use only All content is provided for informational and research purposes only and is not medical advice. Peptides referenced are sold and discussed for laboratory and research use only, not for human consumption. Consult a licensed physician before making any health decision.