One peptide, two very different pharmacokinetic profiles. This Kiwi Peps reference frames CJC-1295 DAC vs no-DAC as a research-design decision, with tables, mechanism and COA notes.
CJC-1295 DAC vs no-DAC is one of the most frequently asked comparisons in GHRH-analog research. The two forms share the same 30-residue GHRH backbone with identical substitutions (D-Ala², Gln⁸, Ala¹⁵, Leu²⁷). The only structural difference is the Drug Affinity Complex — a maleimide linker on Cys³⁰ that covalently binds serum albumin — and yet that single addition changes the pharmacokinetic profile of CJC-1295 by two orders of magnitude.
Head-to-head: CJC-1295 DAC vs no-DAC
| Attribute | With DAC | No-DAC (Mod GRF 1-29) |
|---|---|---|
| Structural difference | Maleimide DAC linker binds albumin covalently | No linker |
| Published half-life | ~6–8 days | ~30 minutes |
| GH release pattern | Sustained bleed | Pulsatile (mimics native GHRH) |
| Reference dosing frequency | Weekly | Multiple pulses per day |
| Preferred blend pairing | Rarely combined with GHSR agonists | Frequently combined with ipamorelin |
| Reference research application | Steady-state exposure and IGF-1 elevation curves | Pulse-amplitude and native-kinetic studies |
Which form fits which research question?
- Pulsatile GH kinetics required → no-DAC (Mod GRF 1-29).
- Sustained GHRH stimulation and steady IGF-1 exposure → DAC.
- Multi-mechanism synergy with GHSR agonists (ipamorelin) → no-DAC pairing dominates the literature.
- Simplified dosing schedule with fewer administration events → DAC.
Mechanism summary
Both forms activate the GHRH receptor on pituitary somatotrophs with identical affinity. The DAC linker does not change receptor engagement — it changes clearance. Covalent albumin binding shields CJC-1295 from renal filtration and enzymatic degradation, converting a ~30-minute molecule into a multi-day one.
- Batch identifier and synthesis date traceable to the lot record
- HPLC purity ≥98% (typically ≥99% for peptides under 30 residues)
- LC-MS confirmed monoisotopic or average mass within ±0.5 Da of theoretical
- Counterion identity and content (acetate or trifluoroacetate) reported
- Bacterial endotoxin and residual solvents per the analytical method
CJC-1295 DAC vs no-DAC FAQ
What does DAC mean in CJC-1295?
DAC stands for Drug Affinity Complex — a maleimide linker on Cys³⁰ that binds covalently to a free cysteine on serum albumin, extending half-life from ~30 minutes to ~6–8 days.
Is Mod GRF 1-29 the same as CJC-1295 no-DAC?
Yes. Mod GRF 1-29 is the common research name for CJC-1295 without the DAC linker.
Which is better for pairing with ipamorelin?
No-DAC. Published research pairs Mod GRF 1-29 with ipamorelin because both are short-acting, producing a clean pulse rather than a sustained overlap.
Which is better for once-weekly reference dosing?
DAC. Its multi-day half-life is the reason it is documented at weekly intervals in published research.
