Description
CJC-1295 with DAC is a modified GHRH analog built on the same 29-amino-acid backbone as the no DAC variant, with one critical addition: a Drug Affinity Complex (DAC) moiety attached via a lysine-maleimide linker. After administration, the DAC component forms a covalent bond with cysteine-34 on serum albumin, effectively turning albumin into a slow-release depot for the peptide. The result is a half-life of approximately 6–8 days — compared to roughly 30 minutes for the no DAC format — and sustained GHRH receptor engagement across an extended observation window. Researchers use the DAC variant when the study requires maintained GHRH pathway activation over days rather than the pulse-length window that the no DAC format produces.
Key Characteristics
- Albumin binding via the DAC moiety is the defining structural feature — covalent bonding to cysteine-34 on serum albumin dramatically extends circulating half-life by piggybacking on albumin’s own long half-life of approximately 19 days
- Sustained GHRH receptor engagement allows researchers to study longer-duration GH axis responses — including IGF-1 dynamics over days rather than hours — that short-acting formats cannot produce within a single experimental session
- Despite the extended half-life, pulsatile GH release is preserved rather than replaced with a flat sustained output — the pituitary’s intrinsic pulse-generation machinery continues to operate, but on top of a maintained GHRH receptor background signal
- Compared to Tesamorelin, which achieves sustained GHRH pathway engagement through a different stabilization strategy (trans-3-hexenoic acid modification rather than albumin binding), CJC-1295 DAC offers a longer effective half-life and is the appropriate choice when observations need to extend beyond a single experimental day
- Clinical pharmacokinetic data exist for this compound from a randomized controlled trial — GH levels increased 2–10-fold and remained elevated for up to 6 days; IGF-1 elevations persisted for 9–11 days following a single dose in healthy subjects
Handling and Storage
Store as lyophilized powder under refrigeration, away from heat, moisture, and light. The DAC modification provides greater enzymatic stability than the no DAC variant, but proper cold-chain storage remains important for maintaining compound integrity across extended experimental protocols. Avoid repeated freeze-thaw cycles.
FAQs
What is CJC-1295 with DAC?
CJC-1295 with DAC is a long-acting synthetic GHRH analog that binds serum albumin through a Drug Affinity Complex moiety, extending its half-life to approximately 6–8 days. It activates the GHRH receptor on pituitary somatotrophs and sustains cAMP-mediated GH signaling across an extended window, making it the appropriate format for research designs that require maintained GHRH pathway activation over multiple days.
Why would a researcher choose CJC-1295 DAC over the no DAC format?
The choice comes down to the observation window the study requires. CJC-1295 no DAC produces a short pulsatile signal and clears in approximately 30 minutes — appropriate for pulsatile dynamics research. CJC-1295 DAC maintains GHRH receptor activation for days — appropriate for studies examining cumulative GH axis responses, longer-duration IGF-1 dynamics, or chronic stimulation models where repeated dosing with a short-acting compound would introduce too much experimental variability.
Does CJC-1295 DAC suppress natural GH pulsatility?
Preclinical and clinical data suggest it does not. Despite the sustained GHRH receptor background, the pituitary continues generating GH pulses. The DAC variant appears to elevate the baseline GH level and increase pulse amplitude without eliminating the underlying pulsatile architecture, which is part of what makes it a useful research tool for studying how sustained GHRH input interacts with the pulse-generating machinery rather than simply replacing it.
