What is the half-life of CJC-1295 No DAC?
CJC-1295 No DAC (also called modified GRF 1-29) has a plasma half-life of approximately 30 minutes. The short half-life is the central pharmacological distinction from the CJC-1295 DAC variant (~6-8 day half-life via albumin-binding) — No DAC supports pulsatile pituitary GH release matching the natural rhythm; DAC produces continuous GHRH-receptor stimulation.
What the research literature says
The CJC-1295 compound was developed in two variants distinguished by the presence or absence of the Drug Affinity Complex (DAC) — an N-terminal maleimidopropionic-acid moiety that covalently conjugates to circulating serum albumin after administration. The DAC variant carries the multi-day plasma half-life characterised in the original Jetté paper (PMID 15817669) and the Teichman clinical-pharmacology work in healthy adults (PMID 16352683). The No DAC variant lacks this modification while retaining the four protease-resistance substitutions on the GHRH 1-29 backbone.
The Alba GHRH-knockout mouse model established that CJC-1295 normalises growth specifically through reconstitution of GHRH-receptor signalling at the pituitary, confirming receptor-specificity of both variants (PMID 16822960). The Ionescu pulsatile-GH-secretion work documented that pulsatile GH release persists during continuous CJC-1295 DAC stimulation, but the underlying point applies more cleanly to the No DAC variant where the brief pituitary-engagement window naturally produces discrete pulses (PMID 17018654).
The Sackmann-Sala work on serum protein profile changes during sustained GH/IGF-1 axis activation is anchored to the DAC variant (PMID 19386527). For the No DAC variant, the dosing-interval choice and pulse-magnitude considerations are the central protocol-design parameters rather than steady-state accumulation considerations.
Why this matters in research context
The 30-minute half-life of the No DAC variant constrains the dosing-interval choice — typical protocols use daily or twice-daily dosing to support the desired pulsatile GH release pattern at a workable frequency. The pharmacology is fundamentally different from the DAC variant, which produces continuous receptor stimulation supporting multi-day dosing intervals. Researchers choosing between variants should anchor the choice to whether the experimental design requires pulsatile or sustained GH-axis stimulation.
Related compounds
- CJC-1295 No DAC 10mg — the compound covered by this answer
- Ipamorelin 10mg — complementary pulsatile GH-secretagogue (~2-hour half-life)
- CJC-1295 + Ipamorelin blend — single-vial co-formulation pairing both pulsatile compounds
Related research questions
- What is the half-life of ipamorelin?
- What is the half-life of tesamorelin?
- Can CJC-1295 be stacked with ipamorelin?
References
- Jetté L 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):3052-3058. [PMID 15817669]
- 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, in healthy adults. J Clin Endocrinol Metab 2006;91(3):799-805. [PMID 16352683]
- 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):4792-4797. [PMID 17018654]
Research-questions pages describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. CJC-1295 No DAC is sold strictly as a research-grade reagent for laboratory and bench research applications.