What Is CJC-1295?
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH) — the endogenous 44-amino-acid peptide secreted by the hypothalamus that stimulates the pituitary gland to produce and release growth hormone (GH). The “CJC” designation comes from the Canadian lab (ConjuChem) that originally developed the compound, and “1295” refers to its internal compound number.
Two distinct forms exist in research literature and the grey market:
- CJC-1295 without DAC (also called Mod GRF 1-29): A 29-amino-acid truncated version of GHRH with four amino acid substitutions that resist enzymatic degradation. Half-life is approximately 30 minutes, creating a GH pulse that mirrors natural physiology more closely.
- CJC-1295 with DAC (Drug Affinity Complex): The same peptide conjugated to a maleimidopropionic acid moiety that binds reversibly to albumin. This dramatically extends half-life to 6–8 days, creating sustained GH elevation rather than discrete pulses.
The distinction matters clinically: pulsatile GH release is how the body naturally operates, while continuous elevation may carry different long-term implications for downstream IGF-1 and GH receptor sensitivity.
Mechanism of Action
CJC-1295 works by binding to GHRH receptors on somatotrophs in the anterior pituitary, stimulating synthesis and secretion of GH. Its key modifications over native GHRH(1-44) are:
- Position 2 substitution (Ala→D-Ala): Blocks DPP-IV (dipeptidyl peptidase IV) cleavage, which is the primary mechanism of GHRH inactivation in plasma.
- Position 8 substitution (Asn→Gln): Prevents asparagine deamidation, increasing chemical stability.
- Position 15 substitution (Gly→Ala): Improves resistance to neutral endopeptidases.
- Position 27 substitution (Met→Leu): Prevents oxidation of the methionine residue.
Together, these modifications extend the half-life from the native GHRH’s ~7 minutes to approximately 30 minutes for Mod GRF 1-29. The DAC addition further extends this to nearly a week by leveraging albumin’s own long half-life (~19 days) as a carrier vehicle.
Downstream Effects
GH secreted in response to CJC-1295 acts on multiple tissues:
- Liver: Stimulates IGF-1 (insulin-like growth factor 1) synthesis, which mediates many of GH’s anabolic effects
- Adipose tissue: Promotes lipolysis (fat breakdown), particularly visceral fat
- Muscle: Increases protein synthesis and satellite cell activity
- Bone: Stimulates osteoblast activity and growth plate activity in adolescents
The CJC-1295 with DAC form also demonstrates synergy with endogenous GHRP (growth hormone-releasing peptide) compounds and ghrelin analogues — a combination frequently studied in clinical research.
Human Clinical Evidence
CJC-1295 is notable for having actual human pharmacokinetic and pharmacodynamic data — which puts it ahead of many research peptides that have only animal studies.
Key Human Trial — Alba et al. (2006)
The foundational human study was published in the Journal of Clinical Endocrinology & Metabolism in 2006. This Phase 1/2 trial enrolled 65 healthy adults aged 21–61 years.
Design: Participants received single subcutaneous injections of CJC-1295 with DAC at doses ranging from 30 to 60 mcg/kg. A subset received multiple weekly doses over 6 weeks.
Results:
- Single dose produced 2–10-fold increases in mean GH concentration lasting for 6 days
- IGF-1 levels rose by 1.5–3-fold above baseline and remained elevated for 9–11 days
- No serious adverse events were observed in the dose ranges studied
- Antibody formation was not detected at standard doses
Limitations: This was a Phase 1 safety and pharmacokinetics study. It was not designed to test body composition, athletic performance, or longevity outcomes. The 6-week multiple-dosing group was small (n=10 per arm).
Long-Term Data Gap
No long-term randomized controlled trials (RCTs) assessing body composition changes, muscle gain, fat loss, or longevity outcomes in healthy adults have been completed and published in peer-reviewed literature. Extrapolating from GH/IGF-1 elevation to specific outcomes requires significant caution.
Pairing With GHRPs
A common research application pairs CJC-1295 with a GHRP (growth hormone-releasing peptide) — most commonly GHRP-2, GHRP-6, or Ipamorelin. The rationale is mechanistic synergy:
- CJC-1295 acts on the GHRH receptor, triggering GH synthesis and release
- GHRPs act on the ghrelin/GHS-R receptor, which amplifies GH pulse amplitude through a complementary pathway
Studies in animals and limited human work suggest that combining GHRH analogues with GHRPs produces GH release that is 5–10x greater than either compound alone — a true synergistic effect, not merely additive. This has been exploited in clinical research into GH secretagogue strategies for GH-deficient adults.
Safety Profile
Based on the available human pharmacokinetic data and clinical observations:
Common effects observed:
- Transient water retention (dose-dependent)
- Flushing sensations immediately post-injection
- Injection site irritation
- Altered glucose metabolism — GH is counter-regulatory to insulin; elevated GH can cause transient insulin resistance
Theoretical concerns:
- IGF-1-driven proliferation: IGF-1 is a potent mitogen. Chronic supraphysiologic IGF-1 elevation is associated with increased cancer risk in epidemiological studies. Whether CJC-1295 produces pathologically high IGF-1 in healthy individuals over the long term is unknown.
- Pituitary desensitization: Continuous GHRH receptor stimulation may theoretically reduce receptor sensitivity. Pulsatile protocols (Mod GRF 1-29 without DAC) are sometimes preferred for this reason.
- Growth promotion in undiagnosed cancer: Standard contraindication for any GH-axis intervention.
No documented serious adverse events were reported in the Alba 2006 trial at therapeutic dose ranges.
Legal and Regulatory Status
CJC-1295 is a research chemical — not approved by the FDA, EMA, or any major regulatory body for human therapeutic use outside of clinical trials. It is not a scheduled substance in most jurisdictions, but legal status varies:
- United States: Legal to purchase and possess for research purposes; not legal for human administration outside clinical research
- Australia: Listed as a prohibited substance under the Therapeutic Goods Administration; Schedule 4 controlled substance
- Canada: In a regulatory grey area; not approved for human use
- WADA/Sports: Banned under Section 2 (Peptide Hormones, Growth Factors) of the Prohibited List
What the Evidence Supports vs. What It Doesn’t
Supported by evidence:
- CJC-1295 reliably increases GH and IGF-1 in healthy adults (Phase 1 human trial)
- The pharmacokinetic profile is well-characterized for CJC-1295 with DAC
- Short-term tolerability at tested doses appears reasonable
Not supported by current evidence:
- Specific muscle gain or fat loss outcomes in healthy adults
- Long-term safety beyond weeks-long observation periods
- Longevity or anti-aging effects
- Cognitive enhancement claims
Summary
CJC-1295 is among the better-characterized research peptides in the GH-axis space, with at least one human pharmacokinetic trial demonstrating its intended biological effect. However, the leap from “elevates GH and IGF-1” to specific performance or longevity outcomes has not been validated in controlled human trials.
The compound is actively used in anti-aging and longevity medicine contexts, and its safety profile in short-term use appears reasonable based on available data. Long-term implications of sustained GH/IGF-1 elevation — particularly regarding metabolic and cancer risk — remain unstudied in this population.
Anyone considering CJC-1295 should do so under medical supervision with appropriate baseline and monitoring labs, including IGF-1, fasting glucose, and HbA1c.
Sources: Alba M, et al. “Once-monthly administration of CJC-1295, a long-acting growth hormone-releasing hormone analog, normalizes growth hormone and insulin-like growth factor I concentrations in patients with adult-onset growth hormone deficiency.” J Clin Endocrinol Metab. 2006;91(8):2953-2960. Thorner MO, et al. GHRH receptor physiology and clinical applications. 2014.
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