CJC-1295 – Complete Guide: Research, Effects & Growth Hormone

Published by Scandinavian Pen Peptide

CJC-1295 is a synthetic analogue of GHRH (Growth Hormone-Releasing Hormone) that has attracted considerable interest in research on body composition, metabolic regulation, and biological ageing. Its extended half-life relative to endogenous GHRH makes it a particularly well-suited research tool for investigating growth hormone secretion dynamics over prolonged timeframes.

Explore our full range of research peptides or visit our Peptide FAQ. For broader context on GH-releasing peptides, see our Ipamorelin research guide and our peptide research guide.

What Is CJC-1295?

CJC-1295 is a 30-amino acid synthetic peptide engineered as a structural analogue of GHRH — the hypothalamic hormone that stimulates growth hormone (GH) release from the anterior pituitary gland. Two principal variants have been developed and studied:

• CJC-1295 No DAC (Drug Affinity Complex) — Also referred to as Mod GRF(1-29). Half-life of approximately 30 minutes. Produces a pulsatile, physiologically consistent pattern of GH release that closely mirrors endogenous secretion.
• CJC-1295 with DAC — Modified with a drug affinity complex enabling binding to serum albumin. Half-life extended to 6–8 days, permitting weekly administration in research protocols.

The distinction between these two variants is significant for study design: the non-DAC form is typically paired with a GH secretagogue such as ipamorelin to produce a defined, pulsatile GH release, while the DAC form sustains elevated GH and IGF-1 levels over a longer period.

Mechanism of Action

CJC-1295 exerts its effects by binding to GHRH receptors (GHRHR) on somatotroph cells in the anterior pituitary. Receptor engagement activates the cAMP/protein kinase A intracellular signalling cascade, leading to the synthesis and secretion of growth hormone.

A key distinction from direct recombinant HGH administration is that CJC-1295 — particularly the non-DAC form — stimulates GH release in a pulsatile manner. This preserves the natural negative feedback mechanisms of the GH/IGF-1 axis, making it a more physiologically relevant model for studying growth hormone dynamics. See CJC-1295 mechanism studies on PubMed.

CJC-1295 and Ipamorelin: A Synergistic Research Combination

The CJC-1295 / Ipamorelin combination is among the most extensively studied pairings in growth hormone secretagogue research. The rationale rests on several well-characterised properties:

• Complementary receptor pathways — CJC-1295 acts via GHRHR; ipamorelin acts via GHS-R1a (the ghrelin receptor). These two pathways converge on GH secretion through distinct mechanisms, producing a synergistic effect when combined.
• Amplified GH release — Studies consistently demonstrate that the combination produces a greater magnitude of GH release than either compound administered in isolation.
• Preserved selectivity — Ipamorelin’s high receptor selectivity means the combination does not produce significant elevations in cortisol or prolactin — a notable advantage over less selective GH secretagogues in research settings.
• Physiological release profile — The pulsatile GH secretion pattern produced by CJC-1295 No DAC combined with ipamorelin closely replicates the natural episodic secretion pattern, making it a valuable model for studying GH physiology.

See CJC-1295 + ipamorelin combination studies on PubMed.

Clinical Research Data

CJC-1295 has been evaluated in human clinical studies. A trial published in the Journal of Clinical Endocrinology & Metabolism assessed CJC-1295 with DAC in healthy adult participants and reported:

• Dose-dependent increases in circulating GH and IGF-1 concentrations.
• A prolonged pharmacokinetic profile consistent with weekly or bi-weekly dosing intervals.
• An acceptable safety profile, with mild and transient adverse effects.

These findings established CJC-1295 as one of the few GHRH analogues with direct clinical evidence in humans, distinguishing it from many peptides that remain exclusively in preclinical research. All original publications are accessible via PubMed — search “CJC-1295 clinical study”.

Body Composition Research

Growth hormone plays a central regulatory role in body composition. By stimulating physiological GH release, CJC-1295 is being studied for its potential to influence several interrelated parameters:

• Lean mass — GH activates protein synthesis pathways and has been associated with the preservation and development of skeletal muscle in research models.
• Adipose tissue — GH exerts lipolytic effects, particularly on visceral adipose tissue, through activation of hormone-sensitive lipase and modulation of lipid metabolism.
• Bone density — The GH/IGF-1 axis plays a well-established role in bone remodelling and mineral density maintenance.
• Recovery and repair — GH promotes cellular repair and tissue regeneration, making CJC-1295 of interest in exercise physiology and recovery research. For related tissue repair compounds, see our guides on BPC-157 and TB-500.

Ageing and Somatopause Research

GH secretion declines progressively with age — a phenomenon referred to as somatopause. This age-related reduction is associated with a characteristic cluster of physiological changes: increased visceral fat accumulation, loss of lean mass, reduced bone mineral density, and altered energy metabolism.

CJC-1295 is being investigated in the context of ageing research as a tool for studying whether restoration of more youthful GH secretion patterns can attenuate or reverse these changes. This represents an active and growing area of endocrinological research with implications for longevity science. See somatopause and GHRH research on PubMed.

Observed Side Effects in Research

Side effects reported in clinical studies have generally been mild and transient, including localised redness or discomfort at the administration site, headache, transient flushing, mild fluid retention, somnolence, and paraesthesias (numbness or tingling). These effects are consistent with the GH secretagogue class and tend to be dose-dependent.

Storage Recommendations

CJC-1295 should be stored at 2–8°C, protected from light and moisture. For long-term storage, −20°C is recommended. Avoid repeated freeze-thaw cycles, which can compromise peptide stability and research reproducibility. All Scandinavian Pen Peptide orders ship in temperature-controlled refrigerated packaging.

Summary

CJC-1295 offers a well-characterised mechanism of action, direct clinical evidence in humans, and a pharmacokinetic profile that distinguishes it from earlier GHRH analogues. Its combination with ipamorelin represents one of the most studied growth hormone secretagogue pairings in current research, with applications spanning body composition, metabolic biology, and ageing science.

For researchers investigating the GH/IGF-1 axis, somatopause, or the downstream effects of physiological GH restoration, CJC-1295 remains a foundational reference compound.

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⚠️ Research use only. CJC-1295 is supplied by Scandinavian Pen Peptide strictly for scientific research purposes. It is not intended for human use. For any health-related questions, consult a qualified medical professional. See our FAQ.