> Research Disclaimer: CJC-1295 (with and without DAC) is a research peptide not approved by the FDA for human therapeutic use (PMID: 42395176). This article summarizes publicly available scientific literature for educational and research purposes only. Not for human use.
What Is CJC-1295?
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), the endogenous hypothalamic peptide responsible for stimulating pituitary growth hormone (GH) secretion. The "CJC" designation comes from ConjuChem Inc., the company that originally developed the molecule. While GHRH itself has a very short half-life (~7 minutes in plasma), CJC-1295 was engineered with specific structural modifications to extend its activity duration dramatically.
The molecule is based on GHRH(1-29) — the first 29 amino acids of GHRH, which constitute the biologically active core — with four amino acid substitutions to improve metabolic stability:
- •Position 2: Ala → D-Ala (reduces DPP-IV cleavage)
- •Position 8: Asn → Gln (reduces deamidation)
- •Position 15: Gly → Ala (improves stability)
- •Position 27: Met → Nle (prevents oxidation)
This modified version is commonly called Modified GRF(1-29) or Mod GRF 1-29, and is the form of CJC-1295 sold without DAC (Drug Affinity Complex). The version with DAC adds a maleimide-PEG linker that allows covalent binding to circulating albumin, dramatically extending half-life from ~30 minutes to 6–8 days.
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CJC-1295 vs CJC-1295 DAC: Key Differences
Understanding the two variants is essential for research context:
| Parameter | CJC-1295 No DAC (Mod GRF 1-29) | CJC-1295 With DAC |
|---|---|---|
| Half-life | ~30 minutes | ~6–8 days |
| GH release pattern | Mimics natural pulsatile GH release | Produces sustained GH elevation |
| IGF-1 response | Transient pulses | Sustained elevation |
| Dosing frequency | Multiple times daily | Once or twice weekly |
| Research context | Pulse mimicry studies | Sustained GH elevation studies |
| Human trial data | Limited | Phase 1/2 data available |
The pulsatile vs. sustained distinction is biologically significant. Growth hormone naturally secreted in pulses, and some researchers hypothesize that the pulsatile pattern from No DAC may have different downstream effects compared to the chronic exposure produced by the DAC variant.
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Mechanism: GHRH Receptor Agonism
CJC-1295 acts as an agonist at the GHRH receptor (GHRHR) — a class B G protein-coupled receptor expressed primarily on pituitary somatotroph cells. Binding of CJC-1295 to GHRHR activates the Gαs/adenylyl cyclase/cAMP/PKA signaling cascade, which:
1. Stimulates GH gene transcription and synthesis in somatotrophs
2. Triggers GH exocytosis from secretory granules
3. Elevates circulating GH → hepatic and peripheral IGF-1 production
The downstream effects of elevated GH and IGF-1 are the primary focus of CJC-1295 research, including effects on:
- •Body composition (lean mass, fat mass)
- •Bone mineral density
- •Metabolic rate
- •Cell proliferation and protein synthesis
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Key Research Data
The Pivotal Human Trial
The landmark human pharmacokinetic study of CJC-1295 DAC was published by Teichman et al. in 2006 in the Journal of Clinical Endocrinology & Metabolism (PMID 16352683). This Phase 1/2 study enrolled healthy adults and administered single and multiple subcutaneous doses of CJC-1295 with DAC.
Key findings:
- •Single doses produced dose-dependent GH elevations that persisted for up to 6 days
- •IGF-1 levels increased by 1.5 to 3-fold above baseline and remained elevated for 9–11 days after a single injection
- •Multiple once-weekly dosing maintained IGF-1 elevation throughout the dosing period
- •The compound was generally well-tolerated in this small study population
This study established proof-of-concept for the "once-weekly" dosing paradigm for CJC-1295 DAC and remains the most cited human-context reference for CJC-1295 research.
GHRH Analog Mechanisms
Follow-up mechanistic research characterized the pharmacodynamic properties of GHRH analogs including CJC-1295, examining receptor binding kinetics, downstream GH pulse characteristics, and IGF-1 axis response patterns. This work helped establish structure-activity relationships for modified GHRH peptides.
Animal Model Research
In rodent studies, including models such as GHRH knockout mice, CJC-1295 and similar GHRH analogs have been examined for effects on (PMID 16822960):
- •Body composition (lean mass gain, fat reduction) — demonstrated in obese animal models
- •Bone density — GHRH analogs have shown effects on trabecular bone in aging animal models
- •Muscle mass preservation in cachexia models
- •IGF-1-mediated anabolic signaling pathways
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Research Forms Available
CJC-1295 is available in the research market in two distinct forms:
CJC-1295 With DAC
Available as lyophilized powder in 2mg and 5mg vials. The DAC modification produces long-acting GH/IGF-1 elevation. Used in research examining sustained growth hormone axis stimulation.
CJC-1295 No DAC (Mod GRF 1-29)
Available as lyophilized powder, typically in 2mg and 5mg vials. Produces short-duration GH pulses when administered. Research more commonly examines this variant in combination with GHRPs (ghrelin mimetics) due to the synergistic release mechanism.
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Platform Pricing
For current CJC-1295 research pricing across verified suppliers, compare live listings at peptides.so/compare/cjc-1295 and the CJC-1295 peptide page.
Based on current platform data, CJC-1295 No DAC 5mg vials range from approximately $35–$75 from established research suppliers, representing $7–$15 per mg. CJC-1295 with DAC 5mg vials are generally priced in a similar range. Use the Peptides Calculator to estimate quantities and costs for research protocols.
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Stacking with Ipamorelin: Synergistic Mechanism
CJC-1295 + Ipamorelin is one of the most commonly referenced combinations in GH secretagogue research. The synergy arises from distinct but complementary mechanisms:
- •CJC-1295 acts at the GHRH receptor → amplifies the GH pulse from the pituitary
- •Ipamorelin acts at GHS-R1a (ghrelin receptor) → independently triggers GH release via a different signaling pathway
When both peptides are present simultaneously, they act on different pituitary receptor systems, producing an additive (or potentially synergistic) GH release greater than either compound alone. This is analogous to how endogenous GHRH and ghrelin normally coordinate GH secretion through complementary receptor pathways.
For detailed research protocol considerations, see the CJC-1295 + Ipamorelin Stack Research Guide.
Additional GH secretagogue context: Body Composition GH Peptide Stack Guide 2026.
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Research Quality Standards
Research-grade CJC-1295 should meet:
- •HPLC purity: ≥98%
- •Mass spectrometry: Confirmed molecular weight (No DAC: ~3367 Da; with DAC: ~3647 Da)
- •Lyophilization: Proper lyophilized cake indicating correct processing
- •Storage: -20°C lyophilized; 4°C reconstituted (use within 30 days)
Compare supplier listings and documentation at peptides.so/compare/cjc-1295.
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Summary
CJC-1295 is a well-characterized synthetic GHRH analog with a meaningful human pharmacokinetic dataset — unusual among research peptides. The with-DAC variant (half-life ~6–8 days) demonstrated dose-dependent GH and IGF-1 elevation in a Phase 1/2 human study, while the No DAC variant (Mod GRF 1-29) offers pulsatile GH stimulation more closely mimicking natural release patterns. Both variants are commonly studied in combination with ghrelin receptor agonists (Ipamorelin, GHRP-2, GHRP-6) to exploit the complementary GHRH + ghrelin receptor stimulation mechanism.
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> For Research Purposes Only. CJC-1295 is not approved by the FDA or any regulatory authority for human therapeutic use. This article is intended for educational purposes and for individuals with appropriate research credentials. Not for human use.
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GH/IGF-1 Axis: Why It Matters in Research
To understand CJC-1295's research significance, it's essential to appreciate the breadth of growth hormone/IGF-1 axis biology. GH is not merely an anabolic hormone — it is a pleiotropic regulator with documented roles in:
Body composition: GH promotes lipolysis (fat breakdown) and lean mass preservation. Adults with GH deficiency (GHD) show characteristic increases in visceral adiposity and decreases in muscle mass that are partially reversible with GH replacement. CJC-1295 research examines whether GHRH analogs can stimulate endogenous GH/IGF-1 restoration in GHD models.
Bone metabolism: IGF-1 is a potent stimulator of osteoblast proliferation and bone matrix formation. GH/IGF-1 axis activation supports bone mineral density (BMD), which declines with age-related GH deficiency. Animal models using CJC-1295 have documented effects on trabecular bone density parameters.
Metabolic function: GH has complex effects on glucose metabolism — insulin-sensitizing over the long term through its IGF-1-mediated effects, but acutely counter-regulatory (raising glucose). Research using GHRH analogs examines these metabolic effects in the context of obesity, metabolic syndrome, and insulin resistance models.
Cardiovascular health: IGF-1 has cardioprotective effects documented in animal models, including anti-apoptotic effects on cardiomyocytes and support for cardiac remodeling after injury. GH-deficient animal models show accelerated cardiovascular aging phenotypes.
Immune function: GH and IGF-1 have immunomodulatory properties, including effects on thymic output and lymphocyte function. This intersection with immune biology makes GHRH analogs potentially relevant to aging and immune research.
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CJC-1295 DAC: Detailed Pharmacokinetic Profile
The Drug Affinity Complex (DAC) technology applied to CJC-1295 represents a significant pharmaceutical innovation. The DAC modification adds a maleimide-PEG linker that spontaneously and covalently binds to cysteine-34 on circulating albumin — the most abundant plasma protein (half-life ~21 days in humans).
Albumin-binding mechanism:
1. CJC-1295 DAC is injected (IV or SC)
2. The maleimide group reacts with free thiols (primarily albumin Cys-34) in plasma
3. Covalent albumin conjugate forms within minutes of injection
4. Albumin-conjugated CJC-1295 is protected from renal filtration and proteolytic degradation
5. Slow release from albumin (via hydrolysis) provides sustained GHRH analog concentration
Published PK parameters from:
- •Terminal half-life: 5.8–8.1 days (vs. ~7 min for native GHRH)
- •GH elevation: Detected for 6+ days after single dose
- •IGF-1 elevation: 1.5–3.0-fold increase, lasting 9–11 days after single injection
- •Bioavailability (SC vs IV): Comparable GH/IGF-1 responses
This pharmacokinetic profile represents a ~1,000-fold extension of half-life compared to native GHRH, achieved through a relatively simple modification — making CJC-1295 DAC one of the most elegant examples of half-life extension technology in peptide pharmacology.
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CJC-1295 No DAC vs GHRH: What the Modifications Achieve
Understanding CJC-1295 No DAC (Mod GRF 1-29) requires appreciating why native GHRH has such a short half-life and how each modification addresses a specific degradation pathway:
Native GHRH(1-29) failure modes:
1. DPP-IV cleavage: The protease dipeptidyl peptidase-IV cleaves between positions 2-3 of GHRH, rapidly inactivating it. Half-life: ~7 min
2. Position 8 deamidation: Asn at position 8 undergoes deamidation, reducing GHRHR binding
3. Position 15 instability: Gly at position 15 is metabolically vulnerable
4. Position 27 oxidation: Met at position 27 undergoes oxidation under physiological conditions
CJC-1295 No DAC modifications:
- •D-Ala at position 2 → blocks DPP-IV cleavage completely (the enzyme cannot process D-amino acids)
- •Gln at position 8 → prevents deamidation at this position
- •Ala at position 15 → improved metabolic stability
- •Nle at position 27 → eliminates methionine oxidation risk
These four changes extend half-life from ~7 minutes to approximately 30 minutes in plasma — still requiring multiple daily administrations for sustained GHRH axis stimulation, but dramatically improving research practicality over native GHRH.
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Research Applications Beyond Body Composition
While body composition (lean mass/fat) is the most commonly discussed application in lay research communities, the CJC-1295 literature covers several other research contexts:
Aging Research (Somatopause): The GH/IGF-1 axis declines progressively with age — a phenomenon called "somatopause." GHRH analogs that restore pulsatile GH secretion are studied in aged animal models as potential interventions to reverse age-related metabolic and physical decline. CJC-1295 has been examined in this context in both aged rodents and the human pharmacokinetic study included subjects across age groups.
Sleep Quality: GH is predominantly secreted during slow-wave sleep (SWS), and GHRH has been shown to promote SWS itself in addition to GH release. Some research has examined whether GHRH analogs can improve sleep architecture in animal models, with implications for sleep research.
Wound Healing: The IGF-1 axis is important for tissue repair — IGF-1 promotes fibroblast proliferation, collagen synthesis, and cellular migration into wound beds. Research has examined GH secretagogues including GHRH analogs in wound healing models, particularly in the context of malnutrition or GH deficiency where healing is impaired.
Cancer Biology (Investigational): The relationship between the GH/IGF-1 axis and cancer biology is complex — IGF-1 is a known mitogen and anti-apoptotic signal in many cancer cell lines. Some researchers study GHRH analogs in the context of cancer biology, examining how GH/IGF-1 axis modulation affects tumor growth in preclinical models. This research context is distinct from therapeutic application and represents mechanistic investigation.
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CJC-1295 vs. Other GHRH Analogs
CJC-1295 should be understood in the context of the broader GHRH analog research space:
| Compound | Type | Half-life | Development Stage |
|---|---|---|---|
| Native GHRH(1-29) | Endogenous peptide | ~7 min | N/A |
| Sermorelin | GHRH(1-29) with fewer modifications | ~15 min | FDA-approved (formerly) |
| Tesamorelin | GHRH analog (trans-3-hexenoic acid) | ~40 min | FDA-approved (Egrifta) |
| CJC-1295 No DAC | Modified GHRH(1-29) | ~30 min | Research only |
| CJC-1295 With DAC | Albumin-binding GHRH analog | ~6-8 days | Research only |
Tesamorelin (Egrifta) represents the FDA-approved GHRH analog approved for HIV-associated lipodystrophy — providing useful human clinical context for GHRH class mechanisms, even though CJC-1295 itself is not FDA-approved.
For a detailed comparison across the full GHRH analog class, see GHRH Analogs Compared: Sermorelin vs CJC-1295 vs Tesamorelin and CJC-1295 vs Sermorelin Research Comparison Guide 2026.
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Reconstitution and Storage for Research
Proper handling of CJC-1295 is essential for maintaining research integrity:
Lyophilized storage: Store at -20°C, protected from light and moisture. Properly stored lyophilized CJC-1295 maintains integrity for 12–24 months.
Reconstitution: Add bacteriostatic water (BAC water) slowly along the vial wall. Do not shake — gently swirl to dissolve. Typical reconstitution concentrations: 0.5–2 mg/mL.
Reconstituted storage: Refrigerate at 4°C. Use within 30 days for maximum peptide integrity.
Freeze-thaw cycles: Minimize freeze-thaw cycles for reconstituted material; multiple cycles degrade peptide integrity.
For comprehensive protocol guidance, see the CJC-1295 Dosage Protocol Guide 2026.
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Research References
CJC-1295 and GHRH analog research:
- •PMID 16822960: GHRH analog pharmacology and growth hormone secretion.
- •PMID 21871962: Long-acting growth hormone-releasing hormone analog development.
- •PMID 16352683: GHRH receptor agonism and GH axis regulation.