What is the difference between CJC-1295 with DAC and no-DAC?

The drug affinity complex, a linker that binds covalently to albumin after injection. With it, half-life is about eight days; without it, roughly half an hour. Since the published trials were measuring the duration and magnitude of the growth hormone response, that difference is the whole subject of the evidence rather than a detail of it.

Are there human studies of CJC-1295?

Yes, three published studies in humans — but all of them used the DAC form. There is no published human trial of the no-DAC form, also sold as Modified GRF (1-29).

Does continuous stimulation flatten growth hormone pulses?

Ionescu and Frohman reported that it did not: pulsatile secretion persisted during continuous stimulation by the DAC form, with pulse amplitude increased rather than the pattern abolished. That is one of the more mechanistically interesting findings in this literature.

Can CJC-1295 with DAC research be applied to no-DAC?

Only the receptor target transfers. Response magnitude, duration, the pulsatility finding and the safety observations are all properties of a molecule that stays in circulation for days, and no published work establishes what any of them look like for one that does not.

Is CJC-1295 approved anywhere?

No, in either form. It is supplied here as a laboratory reagent for in-vitro research and not for human or veterinary use.

Research guides

CJC-1295 (Mod GRF 1-29): what the research says

The best-known CJC-1295 human trial studied the DAC form, not the no-DAC form sold as Mod GRF 1-29. Why the two have very different pharmacokinetics.

Available in the catalogue

Supplied as research material. Sizes and pricing are on the product page. Availability is not a statement about what a compound does.

CJC-1295 NO DAC
Growth Hormone

This is the clearest case in the catalogue of a literature belonging to a molecule other than the one described. It is worth being precise about, because the two forms differ in the single property the published trials were measuring.

Two forms, one name

CJC-1295 is a 29-amino-acid analogue of growth hormone-releasing hormone with four amino acid substitutions that resist enzymatic breakdown. It exists in two forms. The DAC form carries a drug affinity complex, a linker that binds covalently to circulating albumin after injection and extends its half-life to around eight days. The no-DAC form omits that linker; its half-life is roughly half an hour, and it is also sold as Modified GRF (1-29).

The linker is not a minor modification. It is the entire pharmacokinetic proposition. An eight-day half-life produces sustained, continuous receptor stimulation; a thirty-minute half-life produces a brief pulse and lets the pituitary's own rhythm reassert itself. Those are different experiments.

Every human study cited below used the DAC form. There is no published human trial of the no-DAC form. When a summary elsewhere quotes CJC-1295 trial results without specifying the form, it is quoting DAC data.

What the DAC trials found

Teichman and colleagues reported dose-dependent increases in growth hormone and IGF-1 in healthy adults, sustained over several days after a single administration — the result that established the compound's long-acting profile.

Ionescu and Frohman then asked a more interesting question. Growth hormone is normally secreted in pulses, and pulsatility is thought to matter for many of the hormone's effects; a continuously acting stimulus might be expected to flatten it into a steady elevation. They reported that pulsatile secretion persisted during continuous stimulation, with the pulse amplitude increased rather than the pattern abolished. That is a meaningful mechanistic finding about how the axis behaves under sustained GHRH-receptor stimulation.

Sackmann-Sala and colleagues later examined serum protein profile changes accompanying activation of the axis by the compound in normal adults.

What this means for the no-DAC form

The GHRH receptor is the same, and the peptide backbone is the same, so it is reasonable to expect the no-DAC form to stimulate the receptor. What cannot be carried across is anything the trials actually measured: the magnitude of growth hormone and IGF-1 response, its duration, the persistence of pulsatility under sustained stimulation, and the safety observations, all of which are properties of a molecule with a very different residence time.

What studies reported

Each entry states what a study examined and the model it used. Nothing below describes an outcome for a person.

Everything below is drawn from published research, and each entry names the model the study used. Approval status varies by compound and by country, and nothing described here is supplied as a medicine or for use in a person.

Teichman et al. (2006)Journal of Clinical Endocrinology & Metabolism · 91(3):799–805
Reported dose-dependent increases in growth hormone and IGF-1 in healthy adults, sustained over several days.
human, randomised placebo-controlled (CJC-1295 with DAC) Source
Ionescu & Frohman (2006)Journal of Clinical Endocrinology & Metabolism · 91(12):4792–7
Examined whether pulsatile growth hormone secretion survives continuous receptor stimulation, reporting that pulsatility persisted with increased pulse amplitude rather than being replaced by a steady elevation.
human (CJC-1295 with DAC) Source
Sackmann-Sala et al. (2009)Growth Hormone & IGF Research · 19(6):471–7
Characterised changes in the serum protein profile accompanying activation of the GH/IGF-1 axis by the long-acting analogue.
human, normal adult subjects (CJC-1295 with DAC) Source

Adverse and null findings reported

No dedicated safety study has been published for this compound. That is not a finding that none exists — it means the question has not been asked in print, and the gaps below say so.

What the research does not establish

An absence cannot be cited, so these are stated plainly. They are the part of the picture that silence would otherwise hide.

No published human trial has studied the no-DAC form, which is the form supplied under this name in most research catalogues. All three human studies above used the DAC form.
The adverse list is empty because no dedicated safety study of either form has been published beyond the tolerability observations within the efficacy trials.
Long-term consequences of sustained GHRH-receptor stimulation are not addressed. The published trials are short.
The DAC form's development did not result in a marketing authorisation in any jurisdiction, and no phase 3 result has been published.
Because the two forms differ in residence time by more than two orders of magnitude, there is no published basis for estimating an equivalent exposure between them.

Common questions

What is the difference between CJC-1295 with DAC and no-DAC?: The drug affinity complex, a linker that binds covalently to albumin after injection. With it, half-life is about eight days; without it, roughly half an hour. Since the published trials were measuring the duration and magnitude of the growth hormone response, that difference is the whole subject of the evidence rather than a detail of it.
Are there human studies of CJC-1295?: Yes, three published studies in humans — but all of them used the DAC form. There is no published human trial of the no-DAC form, also sold as Modified GRF (1-29).
Does continuous stimulation flatten growth hormone pulses?: Ionescu and Frohman reported that it did not: pulsatile secretion persisted during continuous stimulation by the DAC form, with pulse amplitude increased rather than the pattern abolished. That is one of the more mechanistically interesting findings in this literature.
Can CJC-1295 with DAC research be applied to no-DAC?: Only the receptor target transfers. Response magnitude, duration, the pulsatility finding and the safety observations are all properties of a molecule that stays in circulation for days, and no published work establishes what any of them look like for one that does not.
Is CJC-1295 approved anywhere?: No, in either form. It is supplied here as a laboratory reagent for in-vitro research and not for human or veterinary use.

Compounds covered

The reference page for each compound this article discusses.

CJC-1295 no-DAC

Ipamorelin: what the research says
A selective growth hormone secretagogue with a completed, published human trial. It missed its primary endpoint, and that is the most useful result it has.
Semax: what the research says
An ACTH(4-10) analogue registered as a medicine in Russia and unknown to Western regulators. What the BDNF work reported, and why the English record looks thin.
Peptide shelf life and stability
How long lyophilised and reconstituted peptides keep, and the four things that shorten it: temperature, moisture, light and oxidation. Storage figures included.

About this article

Everything reported here comes from published research, and each finding names the model the study used — cell culture, rat, or human. Findings in one model do not transfer to another, most of the work described is preclinical, and none of it is a claim that a compound is safe or effective for any purpose. Nothing on this page describes doses, routes of administration, or use in a person.

Approval status varies by compound and by country. A few of the substances described are the active ingredient of medicines authorised in the EU; most have no marketing authorisation anywhere and have never been assessed by a regulator. Neither is supplied as a medicine here. All material supplied by ASSAY is sold for in-vitro laboratory research only, and is not a drug, food, cosmetic or medical device, and not for human or veterinary use.

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