CJC-1295 human study 2006 by Teichman explained

The CJC-1295 human study by Sam Teichman and colleagues was published in March 2006 in the Journal of Clinical Endocrinology and Metabolism. Its full title is 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. It is one of the very few placebo-controlled trials of a growth hormone secretagogue peptide in humans, and it is the paper most often cited when CJC-1295 is discussed. This article explains what the trial asked, how it was set up, what the researchers measured and where the limits of the data are.

What the CJC-1295 human study asked

Growth hormone releasing hormone (GHRH) is the natural signal from the hypothalamus that tells the pituitary gland to release growth hormone. The problem with GHRH as a research tool or drug is its very short duration of action. It is broken down within minutes. CJC-1295 is a modified GHRH analogue designed to bind to albumin in the blood, which protects it from breakdown and extends its time in circulation.

The authors set out to answer three questions: What is the pharmacokinetic profile of CJC-1295, in other words how long does it stay in the body? What are its pharmacodynamic effects, meaning what does it do to GH and insulin-like growth factor I (IGF-1) levels? And how safe is it in healthy adults? The background on this peptide and its common research partner is covered in our guide on CJC-1295 and ipamorelin.

How the CJC-1295 human study was done

The paper reports two separate trials, both randomised, placebo-controlled and double-blind, with ascending doses. The first trial lasted 28 days, the second 49 days. The studies were run at two investigational sites. Participants were healthy adults between 21 and 61 years of age.

In the first trial, each participant received a single subcutaneous injection of CJC-1295 at one of four ascending dose levels, or placebo. In the second trial, participants received two or three doses, given weekly or every two weeks. The main outcome measures were the peak concentration and the area under the curve for GH and IGF-1 in plasma. Standard pharmacokinetic parameters were calculated for CJC-1295 itself. The abstract does not state the total number of participants, so we do not give a figure here.

What the CJC-1295 human study found

The results were clear on the main questions:

• Growth hormone: After a single injection, mean plasma GH concentrations rose in a dose-dependent manner by 2 to 10 times baseline. This increase lasted for 6 days or more.

• IGF-1: Mean plasma IGF-1 concentrations rose by 1.5 to 3 times baseline and stayed elevated for 9 to 11 days after a single dose.

• Half-life: The estimated half-life of CJC-1295 was 5.8 to 8.1 days. For comparison, native GHRH has a half-life measured in minutes.

• Multiple doses: After repeated injections, mean IGF-1 levels remained above baseline for up to 28 days. The authors describe this as evidence of a cumulative effect.

• Safety: No serious adverse reactions were reported. The authors describe the compound as safe and relatively well tolerated in this study, particularly at doses of 30 or 60 micrograms per kilogram.

The authors concluded that subcutaneous CJC-1295 produces sustained, dose-dependent increases in GH and IGF-1 in healthy adults and that the data support further development as a therapeutic agent.

Limitations of the CJC-1295 human study

This is a human trial with a strong design, but several limitations apply:

• Small early-phase trials: Ascending dose studies of this kind typically include small groups at each dose level. They are designed to measure hormone levels and tolerability, not clinical outcomes.

• Short duration: The longest observation period was 49 days. Nothing can be said about effects or safety over months or years.

• Healthy participants: The participants were healthy adults. The results do not describe what happens in people with growth hormone deficiency or other conditions.

• Surrogate endpoints: The trial measured hormone concentrations in blood. It did not measure body composition, strength, recovery or any functional outcome.

• Industry involvement: CJC-1295 was developed by a pharmaceutical company, and the trial was part of its development programme. The first author is listed with a consultancy address. This does not invalidate the data, but it is relevant context.

• No replication: The compound did not progress through later-stage trials, and no independent group has repeated this study. The findings therefore stand alone.

What this means for CJC-1295 research

For researchers, the main value of this paper is the pharmacokinetic data. It shows that albumin binding can turn a peptide with a half-life of minutes into one with a half-life of about a week, and that the downstream hormone response follows the same extended time course. These numbers are a reference point for any experiment that uses CJC-1295 in animal models or cell systems.

The trial does not establish any benefit beyond hormone levels, and it does not support use outside controlled research. CJC-1295 is often studied together with ipamorelin, which acts on a different receptor. Both are listed in our growth hormone peptides collection, and our CJC-1295 and ipamorelin blend is supplied as lyophilised powder for laboratory research.

Sources

• Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA (2006). 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. The Journal of Clinical Endocrinology and Metabolism, 91(3), 799-805. doi:10.1210/jc.2005-1536

This article summarises published research for information only. It is not medical advice. All products on this site are sold for laboratory research use only and are not intended for human or veterinary use.