CJC-1295 (without DAC)

What it is

CJC-1295 without DAC is built from the first 29 amino acids of growth hormone-releasing hormone, with four specific amino-acid substitutions designed to make the fragment more resistant to the enzymes that normally break down the natural hormone within minutes. Unlike the related version of CJC-1295 that carries an additional chemical group called DAC, this form does not bind to a blood protein for extended release, so it is designed to act and clear relatively quickly.

The appeal of a short-acting form is that it can set off a quick pulse of growth hormone that mirrors how the body releases it naturally, rather than causing a flat, sustained rise. This reasoning is based on the chemistry of the molecule and on general growth hormone-releasing hormone pharmacology rather than on a study that isolated and tested this specific short-acting form on its own.

How it is studied

This is an important limitation to state plainly: the most frequently cited human study of "CJC-1295," a 2006 trial in healthy adults, was actually conducted using the long-acting, DAC-linked version of the peptide, not the short-acting, no-DAC form described here, because that DAC-linked version was the one taken into clinical testing [1][2]. Direct published human or animal data specifically isolating the no-DAC, short-acting form is very limited, and most of what is understood about it comes from its underlying chemistry and from contrast with the better-studied long-acting version.

What studies report

• The chemical modifications that distinguish CJC-1295 without DAC from unmodified growth hormone-releasing hormone are designed to resist enzymatic breakdown while avoiding the albumin-binding group that gives the DAC version its multi-day duration, which is why the no-DAC form is expected to act over a span of minutes to two hours or so, rather than days. [1]
• In the human trial most often associated with the CJC-1295 name, which used the long-acting DAC-linked version, growth hormone secretion stayed pulsatile rather than becoming a flat, continuous elevation, even though the drug itself remained in circulation for days. [2]

What is not known

Because the two versions of CJC-1295, with and without DAC, are frequently discussed together or even conflated in secondary sources, it is important to be precise: the published human pharmacology data most often cited under the CJC-1295 name concerns the long-acting DAC form, not this short-acting one. Whether the short-acting form behaves as predicted when actually given to people, and what its actual effect on growth hormone pulsing looks like when tested directly, has not been established by an independently published, form-specific human trial.

Reported adverse findings

• No form-specific published human safety data exists for CJC-1295 without DAC; the safety data available in the literature under the CJC-1295 name pertains to the long-acting DAC-linked version, described in that peptide's own entry. [1]

Regulatory status

No national medicines regulator, including the FDA and Health Canada, has approved CJC-1295 without DAC for any use in humans, and it exists only as a research compound.