CJC 1295 with DAC vs no DAC
Both are the same modified GRF(1-29) chain; the DAC version adds a reactive lysine group that binds albumin in the blood. That one change moves its half-life from minutes to days: 5.8 to 8.1 days in healthy adults. Nearly all published human data on 'CJC-1295' used the DAC version.
Side by side
| CJC-1295 with DAC | CJC-1295 (no DAC) | |
|---|---|---|
| Class and structure | Long-acting GHRH analogue: tetrasubstituted hGRF(1-29) plus a C-terminal lysine carrying a maleimido group, the drug affinity complex (DAC), which binds albumin | Short-acting GHRH analogue (Mod GRF 1-29): the same tetrasubstituted GRF(1-29) chain (D-Ala2, Gln8, Ala15, Leu27), 29 amino acids, with no DAC and no albumin binding |
| How long it lasts | Present in rat plasma beyond 72 hours; half-life 5.8–8.1 days in healthy adults | No human data; expected to act briefly, closer to native GRF(1-29), whose plasma half-life in rats was about 10 minutes |
| What's studied | Growth hormone and IGF-1 levels in healthy adults, serum proteins, growth in GHRH knockout mice, a horse doping-control assay | Pharmacokinetics of the parent peptide in rats, receptor binding and structure-activity work on GRF(1-29) analogues |
| Strength of the evidence | Two randomised, placebo-controlled human trials and one follow-up analysis in healthy volunteers, plus rat, mouse and horse work | No human study of the no-DAC molecule; indirect rat and in-vitro evidence only. Two of the six cited studies tested the DAC version and are labelled as such |
| Forms sold here | Lyophilised powder vial | Lyophilised powder vial |
| Sizes sold here | 5 mg and 10 mg vials | 10 mg vial |
| Storage | −20 °C, dry and dark; 2–8 °C once mixed, use within 28 days | −20 °C, dry and dark; 2–8 °C once mixed, use within 28 days |
| Cited studies on our pages | 6 | 6 |
Key differences
The DAC group: CJC-1295 with DAC carries a lysine bearing a maleimido group at the end of the chain, which bonds to albumin after injection. The no-DAC version lacks it, so it circulates freely and is cleared much faster.
Duration: the DAC version had a half-life of 5.8 to 8.1 days in healthy adults. No human pharmacokinetic data exist for the no-DAC version, but its unmodified parent peptide lasted about 10 minutes in rat plasma.
Evidence: the human trials of 'CJC-1295' tested the DAC version. Their results cannot be transferred to the no-DAC molecule, which is why the no-DAC page labels each study by the molecule it tested.
FAQ
What does DAC mean in CJC-1295?
DAC stands for drug affinity complex. It is a lysine carrying a maleimido group, added to the C-terminus of the peptide, that bonds to albumin in the blood. That binding protects the peptide from breakdown and keeps it circulating for days.
Is CJC-1295 without DAC the same as Mod GRF 1-29?
Yes. CJC-1295 without DAC is the tetrasubstituted GRF(1-29) chain with no maleimido lysine, and it is also sold as Mod GRF 1-29. The four substitutions make it more resistant to enzyme breakdown than native GRF(1-29).
Which version was used in the human trials?
The DAC version. The two randomised, placebo-controlled trials in healthy adults and the follow-up study in healthy men all used CJC-1295 with DAC. No study in our records tested the no-DAC molecule in people.
Is CJC-1295 legal in Australia?
Neither version is registered on the ARTG, and there is no TGA-approved product containing either one. Tasman supplies both as research chemicals for laboratory research only, not for human consumption.