CJC-1295

What it is

CJC-1295 (no DAC), also known as Modified GRF 1-29, is a synthetic 30-amino-acid GHRH analog with four amino acid substitutions from native GHRH that were designed to increase stability and receptor binding affinity. The “no DAC” designation distinguishes it from CJC-1295 with DAC (Drug Affinity Complex), which has an additional lysine-maleimidopropionic acid modification that binds albumin and greatly extends half-life.

The four substitutions in CJC-1295 (no DAC) — D-Ala at position 2, Gln at position 8, Ala at position 15, and Leu at position 27 — were designed to resist DPP-4 cleavage and other proteolytic degradation pathways. Its reported half-life is approximately 30 minutes, compared with approximately 7 minutes for native GHRH.

CJC-1295 (no DAC) is not FDA-approved for any use in the United States.

Mechanism of action

Proposed mechanisms come from laboratory, animal, and early pharmacology research. Like native GHRH, CJC-1295 (no DAC) is reported to bind the pituitary GHRH receptor, which is associated with release of endogenous growth hormone (GH). Reported pharmacokinetic differences include:

• A half-life of approximately 30 minutes, compared with approximately 10–20 minutes reported for sermorelin
• Higher reported binding affinity for the GHRH receptor than native GHRH in laboratory studies
• Greater reported resistance to enzymatic degradation than native GHRH

Continuously elevated GH levels (as may occur with long-acting GHRH analogs or with excess recombinant GH) are associated with features of acromegaly, including soft tissue overgrowth, joint problems, insulin resistance, and possibly increased cardiovascular and malignancy risk over time. Whether shorter-acting analogs avoid these effects has not been established in humans.

Research findings

The original CJC-1295 (with DAC) was studied in early-phase clinical trials by ConjuChem in the early 2000s. The clinical development program was eventually discontinued, partly due to concerns about a serious adverse event (heart attack) in one trial participant — though this was not definitively linked to the drug. Much of the published “CJC-1295” data refers to the DAC version, not the no-DAC version.

Published clinical trial data on CJC-1295 (no DAC) specifically is limited. Small pharmacology studies have reported increases in GH and IGF-1 levels after administration, but these studies were not designed to assess clinical outcomes.

In laboratory and early human pharmacology research, GHRH analogs and ghrelin-receptor agonists (GHRPs) have been reported to act through different receptor pathways at the pituitary. Well-controlled human trials establishing the effectiveness and safety of CJC-1295 (no DAC) are lacking.

Side effects and contraindications

The safety of CJC-1295 (no DAC) has not been established in well-controlled human trials, and long-term effects are unknown:

• Because it stimulates the GH/IGF-1 axis, there are theoretical concerns about effects on blood sugar, fluid retention, and growth-promoting signaling in people with existing or undiagnosed cancer
• Products sold outside regulated channels (for example, as “research peptides”) may vary in purity, dose, and sterility

Concerns have been raised for: people with active malignancy, pregnancy and breastfeeding, pituitary disease, uncontrolled diabetes, or active diabetic retinopathy.

What we don’t yet know

Direct comparison of CJC-1295 (no DAC) vs. sermorelin in head-to-head clinical trials is not available. The effects of repeated or long-term exposure have not been characterized in formal studies. Whether raising GH and IGF-1 levels with this peptide produces any meaningful clinical benefit in adults, and how it compares with lifestyle and sleep factors that strongly affect endogenous GH, has not been established.