CJC-1295 exists in two distinct research formulations that produce fundamentally different pharmacokinetic profiles. The choice between them depends entirely on whether the research question requires sustained GH elevation or pulsatile, physiological GH release — a distinction with significant implications for study design.
What Is CJC-1295?
CJC-1295 is a synthetic analog of growth hormone releasing hormone (GHRH), specifically a modified version of GRF(1-29) with amino acid substitutions at positions 2, 8, 15, and 27 that improve metabolic stability. The base peptide binds the GHRH receptor on anterior pituitary somatotrophs, stimulating GH synthesis and secretion.
The DAC Technology
The Drug Affinity Complex is a chemical modification — specifically, a maleimidopropionic acid moiety linked via a lysine residue — that enables the peptide to covalently bind to circulating albumin after injection. Since albumin has a half-life of ~20 days, this "albumin-hitchhiking" strategy dramatically extends the peptide's circulating duration from approximately 30 minutes to 6-8 days.
Pharmacokinetic Comparison
| Parameter | CJC-1295 With DAC | CJC-1295 Without DAC |
|---|---|---|
| Half-life | 6-8 days | ~30 minutes |
| GH release pattern | Sustained elevation | Pulsatile |
| IGF-1 elevation | Prolonged (days) | Transient (hours) |
| Dosing frequency | 1-2x per week in studies | 1-3x daily in studies |
| Physiological relevance | Less (tonic elevation) | More (mimics natural pulses) |
When to Use CJC-1295 With DAC
The DAC version is appropriate for research requiring sustained, chronic GH/IGF-1 elevation — such as long-term anabolic studies, chronic growth-factor exposure models, or protocols where minimizing injection frequency is methodologically important. Teichman et al. (2006) showed a single injection of CJC-1295-DAC elevated GH levels for 6+ days and IGF-1 for 9-11 days in human subjects (Teichman et al., 2006; PMID: 16352683).
When to Use CJC-1295 Without DAC
The non-DAC version (mod GRF 1-29) is preferred for research requiring physiological pulsatile GH release. Natural GH secretion occurs in pulses, primarily during deep sleep, and many GH-dependent processes respond differently to pulsatile vs. tonic exposure. For studies of GH-axis physiology, circadian GH patterns, or protocols combining with GH secretagogues like Ipamorelin, the non-DAC version provides a more interpretable stimulus.
Both Available at Research Vials
CJC-1295 With DAC 5mg and CJC-1295 Without DAC 10mg are both available at researchvials.com.
References
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone. J Clin Endocrinol Metab. 2006;91(3):799-805. PMID: 16352683