CJC-1295
CJC-1295 (Modified GRF 1-29)
CJC-1295 is a synthetic analogue of growth hormone releasing hormone (GHRH) comprising the first 29 amino acids of GHRH with stabilising substitutions. Available in two forms: CJC-1295 without DAC (half-life ~30 min, mimics natural GHRH pulsatility) and CJC-1295 with DAC (Drug Affinity Complex, half-life ~7 days via albumin binding). The without-DAC form is most commonly used in GH optimisation research.
Mechanism of Action
CJC-1295 binds GHRH receptors on pituitary somatotroph cells, stimulating GH synthesis and increasing GH pulse amplitude. Unlike native GHRH (half-life <10 minutes), the modified amino acid substitutions in CJC-1295 resist enzymatic degradation, extending its biological window.
When dosed alongside a GHRP like Ipamorelin, CJC-1295 acts as the amplifying component — increasing the pool of GH available for release while the GHRP (via GHSR-1a activation) triggers the release pulse. The synergy between these two mechanisms results in GH pulses significantly larger than either compound produces alone.
CJC-1295 with DAC (the albumin-binding form) produces a sustained "GH bleed" rather than discrete pulses — elevating IGF-1 continuously over days. This blunts the natural pulsatile rhythm and is generally considered less desirable for physiological GH optimisation than the without-DAC pulsatile approach.
Research Evidence
Phase 1/2 trials with CJC-1295 with DAC confirmed dose-dependent IGF-1 elevation lasting up to 14 days after single injection. CJC-1295 without DAC's pulsatile profile is primarily studied in combination with GHRPs.
CJC-1295 with DAC: Prolonged GH and IGF-1 Stimulation
21 healthy adults; single CJC-1295-DAC injection produced 2–10× increase in mean GH concentrations and 1.5–3× IGF-1 elevation persisting for up to 14 days, confirming albumin-binding depot effect.
Typical Research Protocol
CJC-1295 without DAC is almost always combined with Ipamorelin (1:1 mcg ratio). The two are typically loaded into the same syringe and injected together.
Safety Profile
Reported Side Effects
- Water retention
- Mild headache
- Flushing (post-injection)
- Tingling
- Transient fatigue
Contraindications
- Active malignancy
- Uncontrolled hypothyroidism
- Pregnancy
- Pre-existing pituitary pathology
Common Research Stacks
Frequently Asked Questions
What is the difference between CJC-1295 with and without DAC?
CJC-1295 without DAC (also called Modified GRF 1-29) has a half-life of about 30 minutes and produces pulsatile GH release when combined with a GHRP — mimicking natural GH pulsatility. CJC-1295 with DAC uses an albumin-binding peptide to extend half-life to 7+ days, creating sustained GH elevation. Most researchers prefer the without-DAC form for preserving natural pulsatile GH rhythms.
Can CJC-1295 and Ipamorelin be mixed in the same syringe?
Yes — this is standard research practice. Both peptides are stable in bacteriostatic water and there is no known incompatibility. Mixing them in a 1:1 mcg ratio in the same syringe allows a single injection. The mixed solution should be stored refrigerated and used within 4 weeks.
Does CJC-1295 raise IGF-1 levels?
Yes — CJC-1295 raises IGF-1 as a downstream consequence of increased GH pulse amplitude. IGF-1 is the primary mediator of many of GH's anabolic effects on muscle, bone, and metabolism. In clinical data, CJC-1295 (with DAC) produced IGF-1 elevations of 1.5–3× baseline that persisted for up to 14 days per injection.
How often should I monitor labs on a CJC-1295 protocol?
Baseline IGF-1 and fasting glucose before starting, then IGF-1 at 8 weeks and on completion are the minimum recommended checkpoints. IGF-1 should remain in the upper range of normal but not exceed 300 ng/mL. Glucose monitoring is relevant because GH acutely increases insulin resistance — important for anyone with pre-diabetes or metabolic syndrome.
Is CJC-1295 (without DAC) the same as Modified GRF 1-29?
Yes — "Modified GRF 1-29" and "CJC-1295 without DAC" are the same compound. The "Modified" refers to the four amino acid substitutions that distinguish it from native GHRH(1-29) (sermorelin) and improve DPP-IV resistance. Some suppliers label it CJC-1295 no-DAC to distinguish it from the DAC version.
Key Research References
- Jetté L et al. (2005). hGRF(1-29)-Albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats. Endocrinology.
- Alba M et al. (2006). Once-monthly administration of CJC-1295 to healthy adults. J Clin Endocrinol Metab.
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