What does DAC stand for in CJC-1295?

DAC stands for Drug Affinity Complex, a chemical linker that lets the peptide bind to albumin in the blood. This is what stretches its action from minutes to days.

Is CJC-1295 the same as MOD-GRF 1-29?

No. MOD-GRF 1-29 is the same modified GHRH fragment without the DAC linker, so it acts for a much shorter time. It is often called CJC-1295 without DAC, which adds to the confusion.

Has CJC-1295 been tested in humans?

Only in small early studies in the 2000s, which measured growth hormone and IGF-1 levels in healthy adults. It was never approved, and there are no long-term outcome trials.

CJC-1295 with DAC Peptide: What It Is, Research and Side Effects

What is CJC-1295 with DAC?

CJC-1295 starts from the first 29 amino acids of human GHRH, the same stretch used in sermorelin. Four of those amino acids are swapped to make the peptide harder for enzymes to break down, and a lysine carrying a reactive linker is added at the end. This is the Drug Affinity Complex, or DAC. After injection, the linker attaches the peptide to albumin, the most common protein in blood, which protects it and keeps it circulating.

The Canadian company ConjuChem developed CJC-1295 in the early 2000s. It reached early clinical studies but was never approved for any use. The version without the linker, MOD-GRF 1-29, is often called CJC-1295 without DAC, even though it behaves very differently in the body.

How does CJC-1295 with DAC work?

Like natural GHRH, CJC-1295 binds to GHRH receptors on the growth hormone-making cells of the pituitary gland, prompting them to make and release growth hormone. That raises IGF-1 from the liver. The difference is timing. Natural GHRH is cleared within minutes, while albumin-bound CJC-1295 keeps acting for days. In early human studies, this raised the baseline level of growth hormone between pulses, while the normal pulses continued.

That steady background signal is the main point of debate. Supporters see it as a way to keep growth hormone and IGF-1 elevated for longer. Critics point out that the body normally releases growth hormone in bursts with quiet periods between, and that constant stimulation is less like natural physiology. Whether that matters for long-term health has not been studied.

CJC-1295 with DAC vs without

The two share almost the same peptide backbone, but the DAC changes how long they last. CJC-1295 with DAC binds to albumin and has a half-life of about a week, producing a sustained rise in growth hormone and IGF-1. MOD-GRF 1-29, often called CJC-1295 without DAC, is cleared far more quickly and produces a short pulse closer to the body's own pattern. The published human studies of CJC-1295 used the version with DAC.

What has research looked at?

What is known about CJC-1295 with DAC comes mostly from short studies of hormone levels in small groups. Clinical development stopped before approval, so there are no long-term safety data and no trials measuring outcomes such as body composition, strength or health over time.

Healthy adults: In a 2006 study in healthy adults, a single injection raised growth hormone for several days and IGF-1 for more than a week, and repeat injections kept IGF-1 elevated for longer.
Growth hormone pattern: A related study found that natural growth hormone pulses continued while levels between pulses rose. This steady elevation is often called GH bleed in online discussions.
Animal studies: In mice bred without natural GHRH, CJC-1295 was reported to restore more normal growth.
Muscle, fat, sleep and aging: These are the reasons people discuss CJC-1295, but no published human trial has tested it for these outcomes.

Side effects and cautions

In the early human studies, side effects were mostly mild and included injection-site reactions, headache and flushing. Because the peptide lasts for days, an unwanted effect cannot be quickly reversed by stopping. The sustained rise in growth hormone and IGF-1 also brings the general cautions of the growth hormone axis, and the effects of keeping IGF-1 elevated for long periods are unknown. Talk to a qualified clinician before making decisions about any growth hormone-related compound.

Injection-site reactions: Redness, itching, pain or swelling at the injection site were among the most common effects reported.
Flushing and headache: Warmth, facial flushing and headache have been reported with GHRH analogs, including CJC-1295.
Water retention: Higher growth hormone can cause fluid retention, swelling, joint aches and numbness or tingling in the hands.
Blood sugar: Sustained growth hormone can reduce insulin sensitivity, which matters for people with or at risk of diabetes.
Cancer history: Because IGF-1 promotes cell growth, compounds that raise it for long periods are generally avoided by people with active cancer, and any past history of cancer calls for careful review.