MuscleLedger

CJC-1295: One Human Trial, One Terminated Registration, and a Literature About Catching It

The single human study of CJC-1295 measured hormone concentrations and nothing else. Twenty years later that is still the entire efficacy record — while the detection literature has grown to include two assays for horses.

Leon H · Published 2026-09-08

There is a way to read a compound's scientific literature that tells you more than any individual paper: count what the papers are about. For CJC-1295 the count is unusually stark. Thirty-three records exist. One is the human trial everybody cites. Most of the rest describe how to detect the compound in a doping-control sample, including two that describe how to detect it in a horse. One is a study of what people say about it on forums.

This is research journalism. It contains no usage guidance, this site publishes no dose figures, and dosing questions are answered by Peptifact rather than here.

What it is

CJC-1295 is a synthetic analogue of growth hormone releasing hormone — the hypothalamic signal that tells the pituitary to release GH. Natural GHRH is cleared within minutes, which makes it useless as a therapy. CJC-1295 was built around a drug affinity complex that binds it to circulating albumin, so instead of minutes it persists for days.

That places it in the GHRH-analogue half of the growth hormone secretagogue class, the same family as sermorelin and tesamorelin, and mechanically distinct from ghrelin-receptor agonists like ipamorelin — which is precisely why the two are so often sold as a pair.

The trial, read in full

The study is Teichman and colleagues, The Journal of Clinical Endocrinology & Metabolism, 2006. It is a real study, properly conducted, and this page is not an attack on it.

Design. Two randomised, placebo-controlled, double-blind ascending-dose trials, of 28 and 49 days, at two investigational sites, in healthy adults aged 21 to 61. The first tested ascending single subcutaneous injections; the second tested repeated weekly or biweekly administration.

Stated outcome measures. Peak concentrations and area under the curve of GH and IGF-I; standard pharmacokinetic parameters for CJC-1295.

Results.

Measure Finding
Mean plasma GH after a single injection Up 2- to 10-fold, sustained 6 days or more
Mean plasma IGF-1 Up 1.5- to 3-fold, sustained 9–11 days
Estimated half-life 5.8–8.1 days
After multiple doses Mean IGF-1 above baseline for up to 28 days; evidence of a cumulative effect
Safety No serious adverse reactions reported

The authors concluded that the data "support the potential utility of CJC-1295 as a therapeutic agent."

What is not in the results, because it was not measured: lean mass, fat mass, body weight, strength, exercise capacity, or any functional outcome. This was a pharmacokinetic and pharmacodynamic study — an entirely legitimate and necessary first step in a drug programme, designed to establish that the molecule reaches the blood, does the biochemical thing it was built to do, and does not obviously harm anyone.

It was step one. Step two never happened.

The step that never happened

ClinicalTrials.gov holds one registration for CJC-1295, retrieved 2026-09-08:

NCT00267527 — "A Study to Evaluate CJC 1295 in HIV Patients With Visceral Obesity". Sponsor ConjuChem. Phase 2. Planned enrolment 120. Start December 2005. Status: TERMINATED. No primary completion date. No results posted.

Note the indication. The one attempt to take CJC-1295 into a patient population was aimed at visceral fat, not muscle — the same target that tesamorelin, another GHRH analogue, went on to win an approval for in 2010. Nothing in the registry, in any jurisdiction, has ever tested CJC-1295 against a muscle endpoint.

What the rest of the literature is

Of the 33 PubMed records for CJC-1295, the great majority are analytical chemistry: immunoaffinity purification and high-resolution mass spectrometry for GHRH analogues in human plasma, nano-liquid chromatography methods for urine at picogram concentrations, cationic exchange extraction methods, screens for peptidic drugs in doping-control blood.

Two of them are about horses. A 2019 paper in Drug Testing and Analysis describes a method for confirming CJC-1295 abuse in equine plasma; a second, in the same year and journal, describes an immuno-polymerase chain reaction screen for CJC-1295 and other GHRH analogues in equine plasma. Racehorse doping control has invested in detecting this compound.

And one record is not about the compound at all. A 2016 study in Substance Use & Misuse applied "netnography" to female CJC-1295 use, searching nine bodybuilding forums and analysing 23 discussion threads; its findings concern what users reported wanting from the compound — weight loss, muscle, skin, sleep, injury healing — and their own uncertainty about dosing and long-term consequences in women.

Put the shelf in order and the picture is complete: one pharmacology study, one terminated registration, a large body of work on how to catch it, and one paper on what its users tell each other.

Why this matters more than it looks

The temptation is to treat the hormone result as a proxy for the muscle result — GH went up a lot, therefore muscle. This category has a direct test of that inference, and it failed it.

MK-677, the best-evidenced compound in the same class, raised IGF-1 by 72.9% over twelve months in a 563-patient randomised trial and changed nothing on any of the four efficacy measures that trial was designed to detect. In its muscle trial it raised fat-free mass 1.1 kg over a year while its own authors reported no resulting change in strength or function. Both results are set out on the MK-677 page.

Raising the hormone is the easy part, and CJC-1295 does it more durably than almost anything else in the category. Whether that becomes muscle in a trained adult is the question the entire class has avoided asking, and CJC-1295 has avoided it more completely than any compound in it.

Status

Prohibited in tested sport at all times, in and out of competition, under WADA section S2.2, which names growth hormone releasing factors and their analogues explicitly. Detection methods for GHRH analogues in human plasma and urine are published and validated; our drug testing page carries the detail.

No marketing approval in any jurisdiction. Sold labelled for research use only.

Sources

  • Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne J-P, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab 2006;91(3). PMID 16352683
  • ClinicalTrials.gov registration NCT00267527, retrieved 2026-09-08.
  • Brennan R et al. Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions. Subst Use Misuse 2016. PMID 26771670
  • A method for confirming CJC-1295 abuse in equine plasma samples by LC-MS/MS. Drug Test Anal 2019. PMID 30938069
  • An immuno polymerase chain reaction screen for the detection of CJC-1295 and other growth-hormone-releasing hormone analogs in equine plasma. Drug Test Anal 2019. PMID 30489688
  • WADA Prohibited List, section S2.2.
  • PubMed record counts retrieved 2026-09-08.

Frequently asked questions

Does CJC-1295 build muscle?

Nobody has measured it. Its one human study measured growth hormone and IGF-1 concentrations and pharmacokinetics, and reported no body-composition, strength or functional outcome because it did not collect any. In the twenty years since, no trial has filled that gap. Every claim that CJC-1295 builds muscle is an inference from a hormone curve, not a reading of a result.

What did the CJC-1295 study actually show?

That the molecule does what it was designed to do pharmacologically, and does it for a long time. In healthy adults aged 21 to 61, a single subcutaneous injection raised mean plasma growth hormone two- to ten-fold for six days or more and IGF-1 one-and-a-half to three-fold for nine to eleven days; the estimated half-life was between 5.8 and 8.1 days, and after repeated doses IGF-1 remained above baseline for up to 28 days. The authors reported no serious adverse reactions and concluded the data supported CJC-1295's potential utility as a therapeutic agent. That potential was never developed.

Why was the only CJC-1295 trial terminated?

The registry entry does not state a reason. NCT00267527 was a phase 2 ConjuChem study in HIV patients with visceral obesity, planned for 120 participants, started in December 2005 and listed as terminated with no results posted and no completion date. What the record establishes is factual and limited: the one attempt to take this compound into a patient population did not finish, was never reported, and nothing replaced it.

Is CJC-1295 the same as CJC-1295 DAC?

The compound in the 2006 trial is the long-acting version — the whole point of the molecule is a drug affinity complex that binds it to albumin so it persists for days rather than the minutes a natural GHRH fragment lasts. The multi-day half-life reported in that study is a measurement of exactly that. Material sold without the complex is a different, short-acting molecule with a different profile, and the trial evidence on this page does not transfer to it.

Is CJC-1295 detectable?

Yes, and this is the best-developed part of its science. Published methods detect GHRH analogues in human plasma and urine by immunoaffinity purification and high-resolution mass spectrometry, and two separate 2019 papers describe methods for confirming CJC-1295 in equine plasma. WADA prohibits growth hormone releasing factors and their analogues at all times under S2.2, so out-of-competition testing applies.

Why does a compound with one trial have such a large following?

Because the hormone result is genuinely impressive and travels well as a claim. A two- to ten-fold rise in growth hormone lasting the better part of a week is a striking number, and it is true. The gap it conceals is that a hormone concentration is an input, not an outcome — the one compound in this class whose functional endpoints were properly measured produced about a kilogram of fat-free mass and no strength change over a year.