Peptides - Compound guides
CJC-1295
CJC-1295 is a synthetic GHRH analogue studied in early clinical pharmacology work; it is not an approved medicine and is widely confused with a related compound.
CJC-1295 is a synthetic analogue of growth hormone releasing hormone (GHRH), the natural signal the brain uses to tell the pituitary gland to release growth hormone. It was developed in the 2000s by a biotechnology company exploring whether a long-acting GHRH analogue could raise growth hormone levels with infrequent administration. It did not progress to approval.
Before anything else, a naming problem needs clearing up, because it causes more confusion than any other point in this subject. Two different substances circulate under overlapping names. CJC-1295 with DAC contains a drug affinity complex, a chemical modification that lets the molecule bind to albumin in the blood and stay in circulation for days. What is sold as "CJC-1295 without DAC" is not really CJC-1295 at all - it is modified GRF 1-29, a much shorter-acting GHRH fragment with a half-life measured in minutes. These are pharmacologically different things, and material sold online is frequently mislabelled or described interchangeably. Any discussion that treats them as the same compound is unreliable from the outset.
How it is thought to work
Growth hormone is released in pulses rather than continuously. The hypothalamus produces GHRH, which signals the pituitary to release a burst of growth hormone. That growth hormone travels to the liver, where it drives production of insulin-like growth factor 1 (IGF-1), the messenger responsible for much of what growth hormone is credited with doing. Balancing this is somatostatin, also from the hypothalamus, which acts as the brake. The natural rhythm of growth hormone, with its large overnight pulses, comes from the interplay of these two signals.
CJC-1295 acts at the GHRH receptor on the pituitary - the same receptor the body's own GHRH uses. This is a different site from ghrelin receptor agonists such as ipamorelin or hexarelin, which act at the growth hormone secretagogue receptor. The distinction matters for two reasons. First, a GHRH analogue amplifies the existing signal rather than adding a new one, so its effect is still shaped by the somatostatin brake and by how much capacity the pituitary has. Second, the DAC version's long duration means it does not reproduce the body's natural pulsing pattern; it raises the underlying signal more continuously, which is a meaningfully different physiological situation from a series of sharp pulses, and the consequences of that difference over time are not well understood.
The general principle applies here with particular force: raising a hormone level is not the same thing as producing a benefit. Feedback loops exist precisely to push back against sustained changes, and a number moving on a blood test tells you the drug reached its receptor, not that anything worthwhile followed.
What the research actually shows
Early human pharmacology studies did establish the basic pharmacological point. Researchers investigating single administrations in healthy adults were able to measure sustained increases in circulating growth hormone and IGF-1, in some cases lasting several days after a single administration of the DAC version. As a demonstration that the molecule engages its receptor and has a long duration of action, that work is real.
What is missing is everything above that rung. There are no large, long-duration randomised controlled trials showing that CJC-1295 improves any outcome that a person would notice or value - body composition, strength, recovery, sleep, skin quality, injury healing or any marker of ageing. Development was not carried through to approval. The widespread online claims about body recomposition and anti-ageing effects are inferences drawn from the mechanism and from what is known about growth hormone generally, not findings from trials of this compound. The gap between "it measurably raises a hormone" and "it does something good for people" is the entire distance that has not been travelled.
Where the evidence stops
- There is no meaningful long-term human safety data - no multi-year follow-up in any population.
- Whether the pituitary response diminishes with continued exposure, and how quickly, is not well characterised.
- Effects on insulin sensitivity and blood glucose with sustained use are not established.
- Whether chronically elevated IGF-1 carries risk remains an open and actively debated question in the research literature.
- The consequences of replacing the body's natural pulsatile growth hormone pattern with a more continuous one are poorly understood.
- The persistent mislabelling of DAC and non-DAC material means that even user reports describe an unknown substance.
Legal and regulatory status
CJC-1295 is not an approved medicine in the United Kingdom. It has no MHRA marketing authorisation, so no regulator has evaluated its safety, quality or effectiveness for people. It is sold as a research chemical, typically labelled "research use only", which means exactly what it says: it has not been approved for human use and is not made under medicines-grade quality assurance. There is no requirement for the purity, sterility or content of such material to be verified.
GHRH analogues, including CJC-1295, appear on the World Anti-Doping Agency prohibited list under class S2, prohibited for athletes at all times, in and out of competition.
This lesson is educational content only and is not medical advice. CJC-1295 is not an approved medicine in the UK. Nothing here is a recommendation to use, obtain or try any substance. Any decision about health, medication or treatment belongs with a qualified healthcare professional who knows your circumstances.
Growth-hormone secretagogues
Start with the overview: Growth-hormone secretagogues, explained
Further reading
Sources for this classroom
Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.
