Last updated: May 18, 2026
What CJC-1295 is
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH). The native GHRH is a 44-amino-acid peptide; the (1-29) fragment retains full biological activity. CJC-1295 starts from this (1-29) backbone with four substitutions:
- D-Ala at position 2 (resists DPP-IV cleavage)
- Gln at position 8
- Ala at position 15
- Leu at position 27
The “DAC” (Drug Affinity Complex) variant adds a maleimide linker that covalently binds endogenous albumin via Cys34, extending half-life dramatically.
CJC-1295 No-DAC (Modified GRF 1-29)
Half-life: ~30 minutes
Dosing: 100 µg per dose, 2-3 times daily
Mechanism: Produces discrete GH pulses similar to natural GHRH-stimulated release. Combined with Ipamorelin (GHRP), each pulse is amplified.
CJC-1295 With DAC
Half-life: ~6-8 days (vs 30 minutes without DAC)
Dosing: 1-2 mg per week, single subcutaneous injection
Mechanism: Sustained elevation of baseline GH release rather than pulsatile. Ipamorelin (or other GHRP) still triggers discrete pulses on top of this sustained elevation.
DAC vs no-DAC tradeoffs
| No DAC | With DAC | |
|---|---|---|
| Half-life | ~30 min | ~6-8 days |
| Dosing frequency | 2-3x daily | Once weekly |
| GH release pattern | Pulsatile (biomimetic) | Sustained baseline |
| Total daily dose | 200-300 µg | ~140-280 µg/day equivalent |
| Cost per cycle | Higher (more product) | Lower per dose |
| Convenience | Multiple injections | Single weekly injection |
Most-studied combination: CJC-1295 + Ipamorelin
The CJC-1295 + Ipamorelin stack is the most-researched GHRH/GHRP combination in the research-peptide world. The two work on different pathways (GHRH receptor and ghrelin receptor) producing synergistic GH release.
Common protocols:
- Daily protocol: CJC-1295 no-DAC 100 µg + Ipamorelin 200-300 µg, 2-3x daily, pre-bed and pre-workout
- Weekly protocol: CJC-1295 DAC 2 mg weekly + Ipamorelin 200-300 µg daily
Research / clinical evidence
CJC-1295 was originally developed by ConjuChem as a clinical drug candidate. Phase 1/2 trials showed sustained GH and IGF-1 elevation in healthy adults. Development was discontinued for commercial reasons but the pharmacology is well-characterized.
Side effects
Generally well-tolerated. Reported effects:
- Injection-site reactions (most common)
- Mild flushing post-injection
- Water retention (chronic high-dose use)
- Carpal-tunnel-like paresthesias (chronic high-dose use)
- Possible insulin resistance with extended use (monitor fasting insulin)
Which version should I use — DAC or no-DAC?<br />
Most research-community protocols use no-DAC for biomimetic pulses and ability to time around workouts/sleep. DAC version is more convenient (weekly) but produces sustained rather than pulsatile GH elevation.
Can I use both versions?<br />
Not standard. The DAC version provides sustained baseline; no-DAC adds pulses. Typically one or the other is used with Ipamorelin for the pulse component.
How long until effects show?<br />
IGF-1 elevation measurable within 2-3 weeks. Body composition effects gradual over 8-12 weeks.
Is “Modified GRF 1-29” the same as CJC-1295?<br />
Modified GRF 1-29 typically refers to CJC-1295 without DAC. The two terms are often used interchangeably for the same molecule (the 4-substitution GHRH 1-29 analog).