CJC-1295 with DAC

What is CJC-1295 with DAC?

CJC-1295 with DAC is a long-acting, lab-made version of growth hormone-releasing hormone (GHRH), the brain signal that tells the pituitary gland to release growth hormone. DAC stands for Drug Affinity Complex, a chemical attachment that lets the peptide latch onto albumin, the most abundant protein in blood. That attachment stretches the drug's half-life from minutes to about a week.¹

It was developed in the early 2000s by the Canadian company ConjuChem as a potential treatment for conditions involving low growth hormone. The key human study, published in 2006, showed that a single injection raised growth hormone and IGF-1 for days.¹ Development stopped before any approval, and it has never been approved anywhere.

Today CJC-1295 is sold widely as a research peptide and used by bodybuilders, anti-aging clinics and people seeking muscle growth, fat loss or faster recovery.⁶ Many products labeled "CJC-1295" are actually a different, short-acting peptide without DAC, often called modified GRF 1-29. This page covers the DAC version. It is prohibited in sport.

How CJC-1295 with DAC works

Your body releases growth hormone in bursts, mostly during deep sleep, under the control of two brain signals: GHRH, which says release, and somatostatin, which says stop. CJC-1295 mimics GHRH, so the pituitary releases more growth hormone. Growth hormone then tells the liver to make IGF-1, which drives many of growth hormone's effects on muscle, fat and bone. Because the DAC version stays in the blood for days, it keeps that release signal switched on far longer than natural GHRH.

Technically, CJC-1295 is a modified GHRH(1-29) analog with amino acid substitutions that resist enzymatic breakdown. The DAC is a maleimidopropionic acid linker that forms a covalent bond with cysteine-34 on circulating albumin, protecting the peptide from kidney clearance and degradation. The estimated half-life in humans is 5.8 to 8.1 days.¹ The result is a sustained rise in baseline growth hormone, often called a "bleed", rather than the sharp pulses the body normally produces. Whether that loss of pulsatility matters for long-term safety or effect is the main pharmacological debate about the DAC version.

What the research shows on CJC-1295 with DAC

The core human evidence is two randomized, placebo-controlled, double-blind ascending-dose trials in healthy adults aged 21 to 61, published together in 2006. After a single injection, average growth hormone levels rose two- to tenfold for six days or more, and IGF-1 rose 1.5- to threefold for 9 to 11 days. With repeated weekly or every-other-week doses, IGF-1 stayed above baseline for up to 28 days, showing a cumulative effect. No serious adverse reactions were reported.¹

That is solid evidence that the drug raises growth hormone and IGF-1. It is not evidence that it improves body composition, strength, recovery or health. The trials were short, studied hormone levels as their main outcomes, and involved the developer's own scientists.

No published trial has tested CJC-1295 for fat loss, muscle gain or injury healing in people. A 2026 primer for orthopedic and sports medicine physicians noted that CJC-1295 combined with ipamorelin improved muscle function in mice with steroid-induced muscle loss, but that this finding is limited to animal studies.² Other recent reviews describe the same gap: strong interest, little clinical evidence.³⁴

A 2026 critical review of peptides in sport and bodybuilding found that most published studies examine controlled therapeutic dosing, not the higher or combined protocols common in bodybuilding, and highlighted potential risks including insulin resistance and dyslipidemia.⁶

Studied for: Sustained GH elevation, Body composition, Research into long-acting secretagogues.

CJC-1295 with DAC reference data

CJC-1295 with DAC dosage in published research

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How CJC-1295 with DAC is used in practice

In practice, CJC-1295 with DAC is bought online as powder in vials, mixed with bacteriostatic water and injected under the skin once or twice a week. It is often combined with a growth hormone secretagogue such as ipamorelin, although stacking with the DAC version is less common than with the short-acting form. US compounding pharmacies face restrictions on using CJC-1295, which limits legitimate clinic access.

Online communities shape how it is used. A study of internet forum discussions among women using CJC-1295 found that choices centered on weight loss, muscle, youthful skin, sleep and injury healing. Users were experienced with multiple performance and image drugs, and they voiced concern about dosing and long-term consequences.⁷

Quality is a serious issue. Products are unregulated and often mislabeled or contaminated.⁶ The DAC and non-DAC versions are also frequently confused, so a buyer may not get the drug they think they are using. Anti-doping laboratories can detect CJC-1295 in urine at very low concentrations.⁸

CJC-1295 with DAC risks and side effects

Side effects follow from raising growth hormone and IGF-1 for long periods. Reported effects include water retention, tingling or numbness in the hands similar to carpal tunnel syndrome, joint aches, fatigue, flushing and injection-site reactions. In the 2006 trials, the drug was relatively well tolerated at the doses studied.¹

Sustained growth hormone elevation can reduce insulin sensitivity and raise blood sugar, and reviews have flagged insulin resistance and unfavorable lipid changes with peptide use in bodybuilding.⁶ People with diabetes or prediabetes need to take that seriously. Because IGF-1 promotes cell growth, people with active cancer or a history of cancer have particular reason for caution.

The DAC version's long half-life is also a safety issue. If side effects appear, they cannot be stopped quickly. Long-term effects of continuous, nonpulsatile growth hormone exposure in healthy adults are unknown. A review of peptides in metabolic and endocrine care concluded that further studies are needed before most new peptides can be used safely in humans.⁵

Reported side effects

Alternatives to CJC-1295 with DAC

For adults or children with diagnosed growth hormone deficiency, prescription growth hormone (somatropin) is the established treatment, and long-acting weekly forms such as somapacitan and lonapegsomatropin are FDA approved. Diagnosis requires proper testing by an endocrinologist.

Tesamorelin (Egrifta), an approved GHRH analog, is indicated to reduce excess abdominal fat in people with HIV-associated lipodystrophy. For body composition and recovery in healthy adults, resistance training, adequate protein, good sleep and weight management have far stronger evidence than any growth hormone secretagogue.

Questions for a clinician

• What evidence applies to my situation, and at what level?
• What established alternatives should I consider first?
• What monitoring would be necessary, and how often?
• Can this be prescribed at all where I live, or only sold for research?