CJC-1295: GHRH Analogue Mechanism, DAC vs No-DAC, and GH Research | BiohackLabs
CJC-1295 is a synthetic GHRH analogue that stimulates pulsatile growth hormone secretion by binding and activating the GHRH receptor on pituitary somatotrophs; the DAC (Drug Affinity Complex) form extends half-life from approximately 30 minutes to 6-8 days by covalently binding circulating albumin, whereas the no-DAC form preserves a shorter, more physiological GH pulse pattern.
DAC vs No-DAC Comparison
| Parameter | CJC-1295 with DAC | CJC-1295 no-DAC (Modified GRF 1-29) |
|---|---|---|
| Half-life | 6-8 days | ~30 minutes |
| GH release pattern | Sustained elevated baseline + superimposed pulses | Discrete short-duration pulses (physiological) |
| IGF-1 elevation | 20-70% above baseline for 28 days (Jette et al. 2005) | Transient, normalized between doses |
| Albumin binding | Covalent via maleimido-propionamido linker to Cys-34 | None — standard peptide clearance |
| Dosing frequency | Weekly to biweekly in research models | Daily or multiple times daily |
| Research use case | Sustained GH/IGF-1 elevation studies, body composition | Pulsatile GH studies, stack with GHRP |
| Common stack partner | Often used alone due to long half-life | Ipamorelin (GHRP) for synergistic pulsatile release |
Mechanism of Action
CJC-1295 is a 29-amino-acid synthetic analogue of growth hormone-releasing hormone (GHRH 1-29) engineered with bioconjugation technology to resist enzymatic degradation. Its primary mechanism involves high-affinity agonism at the pituitary GHRH receptor (GHRHR), triggering intracellular cAMP signaling that drives GH synthesis and release from somatotroph cells. The no-DAC variant retains a ~30 minute half-life, producing discrete GH pulses mimicking endogenous secretory events. The DAC variant incorporates a maleimido-propionamido linker enabling covalent conjugation to serum albumin in vivo, extending half-life to 6-8 days.
Clinical Research Evidence
A Phase I/II clinical study by Jette et al. (2005) demonstrated that a single 2 mg injection of CJC-1295 with DAC produced sustained IGF-1 elevations (20-70% above baseline) persisting for 28 days, while maintaining pulsatile GH architecture superimposed on elevated baseline GH. Both forms activate GHRHR via Gs/cAMP signaling to amplify GH secretory burst amplitude and frequency. Body composition research shows GH secretagogues promote lipolysis via HSL activation, increase lean mass via IGF-1/mTOR/4E-BP1 signaling, and improve sleep quality linked to GH pulse timing.
CJC-1295 + Ipamorelin Stack
The most studied combination uses CJC-1295 no-DAC with Ipamorelin. CJC-1295 activates the GHRH receptor (Gs/cAMP pathway) while Ipamorelin activates the ghrelin receptor GHS-R1a (Gq/IP3/Ca2+ pathway). Dual receptor activation produces synergistic GH pulse amplification that neither peptide achieves alone. Available as the GH Recovery Stack at biohackslabs.com for research purposes. Research use only — not intended for human therapeutic use.
FAQ
What is CJC-1295 and how does it work?
CJC-1295 is a synthetic 29-amino-acid GHRH analogue that activates the GHRH receptor on pituitary somatotrophs, triggering cAMP-mediated GH secretion. The no-DAC form produces discrete GH pulses with ~30 minute half-life. The DAC form binds albumin in vivo, extending half-life to 6-8 days for sustained GH/IGF-1 elevation. Both forms increase endogenous GH release rather than providing exogenous GH.
What is the difference between CJC-1295 with DAC and without DAC?
The DAC (Drug Affinity Complex) modification adds a reactive maleimide group that covalently bonds to albumin Cys-34 in vivo, extending half-life from ~30 minutes to 6-8 days. The no-DAC form (Modified GRF 1-29) is cleared more rapidly and produces shorter-duration GH pulses that better mimic endogenous secretory patterns.