Growth hormone declines by roughly 14% per decade after age 30, and researchers have spent the last two decades searching for compounds that can restore pulsatile GH release without the drawbacks of exogenous growth hormone. CJC-1295, a modified growth hormone-releasing hormone (GHRH) analog, has emerged as one of the most studied candidates in this space. With over 30 published studies examining its pharmacokinetics, efficacy, and safety profile, CJC-1295 remains a cornerstone compound in GH secretagogue research heading into 2026.
This guide covers everything researchers need to know about CJC-1295 - its mechanism, the critical DAC vs no-DAC distinction, published clinical data, and how it compares to other GH-releasing compounds.
Key Takeaways
- CJC-1295 is a synthetic GHRH analog (modified GRF 1-29) that stimulates natural, pulsatile growth hormone release from the anterior pituitary
- Two variants exist: CJC-1295 with DAC (Drug Affinity Complex) has a half-life of 6-8 days, while CJC-1295 without DAC (mod GRF 1-29) has a half-life of approximately 30 minutes
- Clinical studies show CJC-1295 DAC increases mean GH levels 2-10 fold and IGF-1 levels by 40-100% in a dose-dependent manner
- It preserves the natural pulsatile pattern of GH release, unlike exogenous GH which creates a single spike
- CJC-1295 is frequently studied alongside Ipamorelin and other GH secretagogues for synergistic effects
Table of Contents
- What Is CJC-1295?
- Mechanism of Action
- CJC-1295 DAC vs No DAC
- Key Published Research
- CJC-1295 vs Other GH Secretagogues
- Research Applications
- Stability, Handling, and Storage
- Frequently Asked Questions
What Is CJC-1295?
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), specifically a modified version of the first 29 amino acids of GHRH known as GRF(1-29). The native GRF(1-29) fragment is biologically active but has an extremely short half-life of about 5-7 minutes in vivo due to rapid enzymatic degradation. CJC-1295 was engineered to solve this problem.
Developed by ConjuChem Biotechnologies (now Aeterna Zentaris), CJC-1295 incorporates four amino acid substitutions at positions 2, 8, 15, and 27 of the GRF(1-29) sequence. These substitutions protect the peptide from dipeptidyl peptidase-IV (DPP-IV) cleavage and general proteolytic degradation, extending its biological activity dramatically.
Key identifiers:
- Sequence: Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH₂ (modified GRF 1-29)
- Molecular weight: ~3,367 Da (without DAC); ~7,365 Da (with DAC)
- CAS number: 863288-34-0 (DAC variant)
- Half-life: ~30 minutes (no DAC) / 6-8 days (with DAC)
Mechanism of Action
CJC-1295 acts as an agonist at the GHRH receptor (GHRH-R) on somatotroph cells in the anterior pituitary gland. When it binds to the GHRH receptor, it initiates a signaling cascade that stimulates the synthesis and secretion of growth hormone.
The mechanism follows this pathway:
- Receptor binding - CJC-1295 binds to the GHRH receptor on pituitary somatotrophs
- cAMP activation - receptor binding activates adenylyl cyclase, increasing intracellular cyclic AMP (cAMP) levels
- PKA signaling - elevated cAMP activates protein kinase A (PKA)
- GH gene transcription - PKA phosphorylates the transcription factor Pit-1, which upregulates GH gene expression
- GH secretion - stored GH vesicles are released in a pulsatile manner, amplifying natural GH pulses rather than creating artificial spikes
What makes this mechanism particularly notable is that CJC-1295 preserves the body's natural feedback loops. Somatostatin (the GH-inhibiting hormone) still functions normally, preventing excessive GH elevation. This stands in contrast to exogenous GH administration, which bypasses pituitary regulation entirely. Research by Teichman et al. (2006) confirmed that CJC-1295 DAC produced sustained GH elevation while maintaining pulsatility - a critical distinction for long-term research applications.
CJC-1295 DAC vs No DAC
This is the most important distinction researchers must understand. The two variants have fundamentally different pharmacokinetic profiles.
CJC-1295 with DAC features a Drug Affinity Complex - a reactive chemical group (maleimidopropionic acid) that forms a covalent bond with serum albumin after subcutaneous injection. This albumin binding is what extends the half-life from minutes to days (Jetrea et al., 2005). The result is a sustained, continuous elevation of GH levels rather than discrete pulses.
CJC-1295 without DAC (often called Modified GRF 1-29 or mod GRF) retains the four protective amino acid substitutions but lacks the albumin-binding moiety. It has a half-life of approximately 30 minutes and produces sharp, discrete GH pulses that more closely mimic natural physiology.
| Feature | CJC-1295 with DAC | CJC-1295 without DAC (mod GRF 1-29) |
|---|---|---|
| Half-life | 6-8 days | ~30 minutes |
| GH release pattern | Sustained elevation | Discrete pulses |
| Administration frequency | 1-2x per week in studies | 1-3x daily in studies |
| Albumin binding | Yes (covalent) | No |
| Pulsatility preserved | Partially | Yes |
| Clinical trial data | Phase II completed | Limited formal trials |
| Research popularity | High | Very high |
The choice between variants depends on the research question. Studies examining sustained GH exposure typically use the DAC variant. Studies focused on mimicking natural GH physiology prefer no-DAC, often combined with a GH secretagogue like Ipamorelin to amplify pulse amplitude. For step-by-step protocols on combining these compounds, see our Ipamorelin how-to guide.
Key Published Research
Teichman et al. (2006) - The Landmark Trial
The most cited CJC-1295 study was published in the Journal of Clinical Endocrinology & Metabolism. This Phase II, dose-escalation trial enrolled 33 healthy adults aged 21-61 and tested single subcutaneous doses of CJC-1295 DAC ranging from 30 to 300 mcg/kg.
Key findings:
- GH levels increased 2-10 fold depending on dose
- IGF-1 levels increased 40-100% above baseline
- Elevated GH and IGF-1 levels persisted for 6-14 days after a single injection
- No serious adverse events were reported
- The compound was well-tolerated across all dose groups
This study established CJC-1295 DAC as one of the longest-acting GH secretagogues ever tested in humans (Teichman et al., J Clin Endocrinol Metab, 2006; DOI: 10.1210/jc.2005-2664).
Alba et al. (2006) - Multiple Dose Study
A follow-up study examined weekly and biweekly dosing of CJC-1295 DAC over 2-3 months. Results showed:
- Sustained IGF-1 elevation of 40-100% throughout the dosing period
- GH response did not diminish with repeated dosing (no tachyphylaxis)
- Fat-free mass increased in a dose-dependent trend
- The compound maintained its efficacy over extended administration periods
Synergistic Studies with Ipamorelin
Multiple preclinical studies have examined CJC-1295 (no DAC) in combination with the ghrelin mimetic Ipamorelin. The rationale is straightforward: CJC-1295 acts on the GHRH receptor while Ipamorelin acts on the GHS receptor (ghrelin receptor). These are two distinct pathways converging on the same outcome - GH release. When activated simultaneously, the GH pulse amplitude is significantly greater than either compound alone, a synergy confirmed in animal models and reflected in the widespread research interest in this pairing.
CJC-1295 vs Other GH Secretagogues
Understanding where CJC-1295 fits in the broader landscape of GH-releasing compounds is essential for researchers designing protocols. For a full head-to-head breakdown covering mechanism, pharmacokinetics, and combination stacks, see the CJC-1295 vs Other GH Secretagogues comparison guide.
| Compound | Type | Receptor | Half-life | Oral? | GH Pattern |
|---|---|---|---|---|---|
| CJC-1295 DAC | GHRH analog | GHRH-R | 6-8 days | No | Sustained |
| CJC-1295 no DAC | GHRH analog | GHRH-R | ~30 min | No | Pulsatile |
| MK-677 | Ghrelin mimetic | GHS-R1a | ~24 hours | Yes | Sustained |
| Ipamorelin | GH secretagogue | GHS-R1a | ~2 hours | No | Pulsatile |
| GHRP-6 | GH secretagogue | GHS-R1a | ~20 min | No | Pulsatile |
| Sermorelin | GHRH analog | GHRH-R | ~10 min | No | Pulsatile |
CJC-1295 without DAC and MK-677 are often compared because they represent two different strategies for GH enhancement. MK-677 works through the ghrelin pathway and is orally active, making it convenient for research settings. CJC-1295 works through the GHRH pathway, which offers a potentially cleaner GH release profile without the appetite-stimulating effects associated with ghrelin receptor activation. For a deeper dive into MK-677 specifically, see our MK-677 complete research guide.
Research Applications
CJC-1295 has been investigated across several research domains:
Growth Hormone Deficiency Models
The primary clinical development pathway for CJC-1295 DAC was adult growth hormone deficiency (AGHD). Phase II trials demonstrated it could restore IGF-1 levels to normal ranges in GH-deficient subjects without the need for daily GH injections. This reduced injection frequency (weekly vs daily) was considered a significant potential advantage.
Body Composition Research
Multiple studies have examined CJC-1295's effects on body composition markers. The sustained GH and IGF-1 elevation produced by the DAC variant has been associated with improvements in lean body mass and reductions in visceral adiposity in both animal and early human studies. Researchers interested in peptides for body composition often compare CJC-1295 with compounds like AOD-9604, which targets fat metabolism through a different mechanism.
Sleep and Recovery Research
Growth hormone secretion is tightly linked to sleep architecture, with the largest natural GH pulse occurring during slow-wave sleep. CJC-1295 without DAC, administered before sleep, has been studied for its potential to amplify this natural nocturnal GH pulse. This approach aligns with the broader research interest in peptides that support recovery processes, similar to the tissue repair research around BPC-157 and TB-500.
Aging Research
The age-related decline in GH secretion (somatopause) has driven interest in CJC-1295 as a tool for aging research. Because it amplifies endogenous GH release rather than replacing it, CJC-1295 preserves the pituitary's regulatory capacity - a feature that distinguishes it from exogenous GH in longitudinal research designs.
Stability, Handling, and Storage
CJC-1295 requires proper handling to maintain its research utility:
- Lyophilized form: Store at -20°C for long-term storage. Stable for 24+ months when kept sealed and frozen
- Reconstituted form: Use bacteriostatic water. Store at 2-8°C (refrigerator). Use within 3-4 weeks for optimal stability
- Light sensitivity: Moderate. Store in amber vials or away from direct light
- Reconstitution: Add bacteriostatic water slowly along the vial wall. Do not shake - swirl gently. For detailed reconstitution protocols, see our peptide reconstitution guide
- Purity verification: Third-party COA testing via HPLC should show average 99.7% purity. Learn how to read a peptide COA to verify quality
CJC-1295 with DAC is generally considered more stable than the no-DAC variant due to the albumin-binding moiety providing additional structural protection. However, both variants are susceptible to degradation from repeated freeze-thaw cycles, which should be avoided.
Frequently Asked Questions
What is the difference between CJC-1295 and Sermorelin?
Both are GHRH analogs, but they differ significantly in half-life and potency. Sermorelin is the natural GRF(1-29) sequence with a half-life of about 10 minutes. CJC-1295 (mod GRF 1-29) incorporates four amino acid substitutions that extend its half-life to approximately 30 minutes and improve its resistance to enzymatic degradation. CJC-1295 with DAC extends this further to 6-8 days through albumin binding. In research, CJC-1295 has largely replaced Sermorelin due to its superior pharmacokinetic profile.
Can CJC-1295 be combined with other peptides in research?
Yes. The most commonly studied combination is CJC-1295 (no DAC) with Ipamorelin. Because they act on different receptors (GHRH-R and GHS-R respectively), they produce synergistic GH release that exceeds either compound alone. This combination exploits both the "accelerator" (GHRH pathway) and "amplifier" (ghrelin pathway) mechanisms of GH secretion simultaneously.
How long does it take for CJC-1295 to elevate IGF-1 levels in research?
Clinical data from Teichman et al. (2006) showed that IGF-1 levels began rising within 24-48 hours of a single CJC-1295 DAC injection and peaked at approximately day 8-10. Levels remained elevated above baseline for up to 14 days. With the no-DAC variant, GH pulses occur within 15-30 minutes but IGF-1 elevation requires repeated dosing over several days to reach steady state.
Does CJC-1295 affect cortisol or other hormones?
Clinical studies have consistently shown that CJC-1295 is selective for GH release. Unlike some GH secretagogues (particularly GHRP-6 and hexarelin), CJC-1295 does not significantly affect cortisol, prolactin, or ACTH levels at therapeutic doses. This selectivity is one of its advantages in controlled research settings where confounding hormonal changes need to be minimized.
What is the recommended storage for CJC-1295?
Lyophilized CJC-1295 should be stored at -20°C for long-term preservation. Once reconstituted with bacteriostatic water, it should be refrigerated at 2-8°C and used within 3-4 weeks. Avoid repeated freeze-thaw cycles as they accelerate degradation. For comprehensive storage guidance, see our peptide storage guide.
This article is for research and educational purposes only. CJC-1295 is sold as a research chemical and is not intended for human consumption. Always consult applicable regulations in your jurisdiction. Browse our full library of research peptide guides for more in-depth compound profiles.