CJC-1295

Overview

CJC-1295 is a synthetic 29-amino-acid peptide analog of growth hormone-releasing hormone (GHRH), engineered with specific amino acid substitutions to resist enzymatic degradation and extend its biological half-life. Developed by ConjuChem Biotechnologies, CJC-1295 is available in two distinct forms: with Drug Affinity Complex (DAC) and without DAC (also known as Modified GRF(1-29) or Mod-GRF). The two variants have markedly different pharmacokinetic profiles, which has significant implications for research protocols and clinical investigation.

The molecular weight of CJC-1295 without DAC is approximately 3,367.9 Da, while the DAC-conjugated version has a molecular weight of approximately 3,647.3 Da. The DAC moiety enables covalent binding to serum albumin following subcutaneous injection, which dramatically extends the peptide’s circulating half-life.

Mechanism of Action

CJC-1295 functions as a GHRH mimetic, binding to GHRH receptors (GHRH-R) on somatotroph cells in the anterior pituitary gland. This binding stimulates the synthesis and secretion of growth hormone (GH) through a cyclic AMP (cAMP)-dependent signaling cascade.

Pulsatile GH Release

Importantly, CJC-1295 amplifies the natural pulsatile pattern of GH secretion rather than producing a continuous, non-physiological elevation. This distinguishes it from exogenous GH administration, which bypasses the hypothalamic-pituitary regulatory axis. The peptide stimulates GH release in response to GHRH receptor activation while preserving the negative feedback mechanisms that normally regulate GH levels.

DAC vs. No-DAC Variants

The two forms of CJC-1295 differ substantially in their pharmacokinetics:

Property	CJC-1295 without DAC (Mod-GRF)	CJC-1295 with DAC
Half-life	30 minutes to 2 hours	6 to 8 days
GH release pattern	Acute pulsatile release	Sustained, elevated baseline with preserved pulsatility
Dosing frequency	Multiple times daily	Once to twice weekly
Albumin binding	No	Yes (covalent via DAC)
Molecular weight	~3,367.9 Da	~3,647.3 Da

The DAC moiety consists of a reactive chemical group (maleimidopropionic acid) that forms a covalent bond with serum albumin after injection. This albumin conjugation protects the peptide from enzymatic degradation and renal clearance, resulting in a dramatically extended half-life.

Downstream Effects

The GH secretion stimulated by CJC-1295 triggers downstream production of insulin-like growth factor 1 (IGF-1) from the liver. IGF-1 mediates many of the anabolic and metabolic effects attributed to growth hormone, including protein synthesis, cellular proliferation, and metabolic regulation.

Research Evidence

The most widely cited clinical study on CJC-1295 was published by Teichman et al. in the Journal of Clinical Endocrinology and Metabolism (2006). This randomized, placebo-controlled trial in healthy adults (ages 21–61) demonstrated:

• GH elevation: Dose-dependent increases in mean plasma GH concentrations by 2- to 10-fold, sustained for 6 days or more following a single subcutaneous injection
• IGF-1 elevation: Mean plasma IGF-1 concentrations increased by 1.5- to 3-fold, sustained for 9 to 11 days
• Half-life: Estimated half-life of CJC-1295 (with DAC) was 5.8 to 8.1 days
• Tolerability: The peptide was described as “safe and relatively well tolerated,” particularly at doses of 30 or 60 mcg/kg

After multiple doses, mean IGF-1 levels remained elevated above baseline for up to 28 days, suggesting cumulative effects with repeated administration.

Additional preclinical research published in the American Journal of Physiology — Endocrinology and Metabolism (2006) demonstrated that once-daily CJC-1295 administration normalized growth in GHRH knockout mice, confirming its biological activity as a functional GHRH analog.

Potential Applications

Based on published research, areas of investigational interest include:

• Growth hormone deficiency — as a potential alternative to exogenous GH replacement that preserves physiological pulsatile secretion
• Age-related GH decline — investigation of whether GHRH analog therapy can address the progressive decline in GH secretion that accompanies aging (somatopause)
• Body composition — research into effects on lean body mass, fat distribution, and metabolic parameters
• Sleep quality — GH secretion is closely linked to slow-wave sleep, and some research has explored whether GHRH analogs influence sleep architecture
• Recovery and tissue repair — through the downstream effects of elevated GH and IGF-1 on protein synthesis and cellular repair

CJC-1295 is not FDA-approved for any therapeutic indication. These areas represent research directions, not validated clinical applications.

Safety Considerations

In the Teichman et al. clinical trial, CJC-1295 was generally well tolerated. Reported adverse effects included:

• Common: Injection site reactions (pain, erythema, swelling), transient flushing, headache
• Less common: Diarrhea, dizziness, abdominal pain
• Theoretical concerns with sustained GH/IGF-1 elevation: Insulin resistance, fluid retention, joint pain, carpal tunnel syndrome, and potential effects on cellular proliferation

Important safety limitations include:

• Clinical trial data is limited to short-duration studies (28 to 49 days); long-term safety data in humans is essentially nonexistent
• Sustained elevation of GH and IGF-1 over months or years carries theoretical risks that have not been systematically evaluated in the context of CJC-1295
• Individuals with active malignancies or a history of cancer should exercise particular caution, as IGF-1 signaling has been implicated in tumor cell proliferation
• The peptide is not produced under pharmaceutical-grade regulation for most commercial sources, raising concerns about purity and consistency

Qualified medical supervision is essential for any consideration of CJC-1295, and individuals should be aware of the limited human clinical evidence base.