CJC-1295: what two small 2006 studies showed, and why nothing followed

CJC-1295 has exactly two published human studies, both from 2006, both short, and both in healthy volunteers. They showed that a single injection of the original drug, the version with a “DAC” albumin-binding tail, lifted growth hormone and IGF-1 for a week or more [2,3]. That is where the human story stops. The company ended development the same year, and the version most people now buy, “CJC-1295 no DAC”, has no published human data of its own.

What it is, and why there are two of them

Growth hormone-releasing hormone (GHRH) is the hypothalamic signal that tells the pituitary to release growth hormone. Drug developers have long worked with a shorter, active fragment of it, GRF(1-29): its first 29 amino acids [1]. The trouble with native GHRH as a drug is its short duration of action, which is the problem CJC-1295 was built to solve [2].

In the early 2000s the Canadian company ConjuChem took that 29-amino-acid fragment, swapped four of its amino acids, and bolted a reactive chemical group onto an extra lysine at the end [1]. After injection, that group latches permanently onto albumin, the most abundant protein in blood, so the peptide rides around on albumin and outlasts native GHRH by days. In rats, the lead compound was still detectable in plasma beyond 72 hours and produced four times the growth hormone response of unmodified GRF(1-29) over two hours [1]. ConjuChem called the albumin-binding technology Drug Affinity Complex, which is where “DAC” comes from.

The two products sold today under the CJC-1295 name are therefore different molecules:

That last row matters. When a vendor or forum cites the 2006 trials for “no DAC”, they are citing data for a different drug. Without the albumin anchor there is no reason to expect a week-long effect, and nobody has published a human pharmacokinetic study to say what the real duration is. A 2026 clinical review of GH-axis peptides sold as research compounds treats them as separate agents for the same reason [7].

How it is thought to work, in brief: CJC-1295 binds the GHRH receptor on pituitary somatotroph cells and prompts them to release the growth hormone they already make. Growth hormone then drives the liver to produce IGF-1. Because it works upstream, it depends on a pituitary that can still respond, and the body’s normal brakes (somatostatin, IGF-1 feedback) remain in play. That is the theory, and the human data below are consistent with it, but they are thin.

The human evidence

Teichman and colleagues, 2006

This paper reports two randomised, placebo-controlled, double-blind, ascending-dose trials in healthy adults aged 21 to 61 [2]. The first gave one of four single doses under the skin; the second gave two or three doses a week or two weeks apart, over 28 and 49 days in total.

After a single injection, mean growth hormone rose two- to tenfold and stayed up for six days or more, depending on dose. Mean IGF-1 rose 1.5- to threefold and stayed raised for 9 to 11 days. The estimated half-life was 5.8 to 8.1 days. With repeated doses, IGF-1 stayed above baseline for up to 28 days, which the authors read as a cumulative effect [2].

No serious adverse reactions were reported, and the authors described the drug as relatively well tolerated, “particularly at doses of 30 or 60 microg/kg” [2]. The trial measured hormones, not outcomes: there was no body composition, strength, sleep or quality-of-life endpoint.

Ionescu and Frohman, 2006

The obvious worry with a drug that stimulates the GHRH receptor nonstop for a week is that it might flatten the natural pulses of growth hormone, which matter for many of its effects. Ionescu and Frohman tested this in healthy men aged 20 to 40 [3]. They sampled blood every 20 minutes for 12 hours overnight, before and one week after a single injection of 60 or 90 mcg/kg.

The pulses survived. Their frequency and size did not change. What changed was the floor between pulses: trough growth hormone rose 7.5-fold, mean growth hormone rose 46% and IGF-1 rose 45% [3]. The two doses gave similar results. This was an uncontrolled before-and-after comparison, and it tells us about hormone patterns over one night, not about anything a person would notice.

Why development stopped

In July 2006 ConjuChem halted a phase 2 trial of CJC-1295 in people with HIV-associated abdominal fat after a participant died at a study site in Argentina, according to a contemporary news report [5]. The treating physician reportedly judged the most likely cause to be undiagnosed coronary artery disease unrelated to the drug, but the study was stopped anyway [5]. We could not find a peer-reviewed publication of that trial’s results, and no further human trials of CJC-1295 appear in the medical literature.

How it compares with the GHRH drug that was approved

It is worth setting CJC-1295 next to tesamorelin, because the two were chasing the same patients at the same time. Tesamorelin is also a stabilised GHRH analogue, but it is the full 44-amino-acid hormone with a small chemical cap, injected daily. Its developer ran a phase 3 trial of 412 people with HIV and excess abdominal fat, published in 2007, which showed visceral fat falling 15.2% over 26 weeks against a 5.0% rise on placebo [9]. It was approved by the FDA in November 2010 [10].

So the GHRH-analogue approach can produce a measurable, imaged change in a defined group of patients when someone runs the trials. CJC-1295 never got that far. Its longer action was the commercial selling point, and it is also the open safety question: a drug that keeps IGF-1 raised for a week cannot be stopped quickly if something goes wrong, and nobody has tested whether weekly dosing gives the same results as tesamorelin’s daily injections.

What the animal work suggests

In mice bred without their own GHRH, daily CJC-1295 normalised growth [4]. That shows the molecule can do what it was designed to do in an animal with no competing signal. It says little about adults with a working pituitary, and nothing about long-term safety.

Safety and side effects

The formal safety record is two short studies in healthy volunteers, reporting no serious adverse reactions [2,3]. That is not enough to rule out uncommon or delayed harms. Whatever sustained GH and IGF-1 elevation does in general applies in principle; a 2026 clinical review lists fluid retention, musculoskeletal symptoms, injection-site reactions and dysglycaemia among problems reported with GH-axis peptides in general [7].

Two points are specific to what people actually use. The no-DAC product has no human safety data at all. And products sold for research use are not made to pharmaceutical standards, so content and purity are unverified. The FDA’s compounding safety page says the agency has identified serious adverse events associated with CJC-1295, “including increased heart rate and systemic vasodilatory reaction”, and flags a risk of immune reactions and limited clinical data [8]. It does not say how many cases, or in what setting. A 2016 study of online forums found women discussing CJC-1295 for weight loss, muscle, skin and sleep, and worrying about how to judge a dose, which the authors saw as a public-health gap [6].

Legal and regulatory status

• US: CJC-1295 has never been approved by the FDA. The FDA’s page on bulk substances that may present significant safety risks in compounding now lists CJC-1295 among nominations that were withdrawn, rather than in its active “category 2” [8].
• UK: not licensed as a medicine.
• Sport: prohibited at all times. The 2026 WADA Prohibited List names CJC-1295 under S2.2.4, growth hormone releasing factors [11].

What we still don’t know

• Whether CJC-1295 changes body composition, strength, recovery or sleep in anyone. No study measured it.
• How long the no-DAC form actually lasts in humans, and whether its effect on growth hormone matches what vendors claim.
• The results of the halted 2006 phase 2 trial, which were never published in a journal.
• What happens with months of use: IGF-1 levels, glucose tolerance, antibodies, and any effect on existing tumours.
• Whether women respond differently. The pulsatility study enrolled only men [3].

Educational content only — not medical advice. Many peptides discussed on HPR are not approved for human use. Talk to a qualified clinician before making any decision about your health.

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