DAC is a chemical addition that, after injection, binds the CJC-1295 molecule to blood albumin and extends its duration of action from about 30 minutes to 6 to 8 days. The version with DAC maintains a steady, raised level of growth hormone and needs to be given only once or twice a week. The version without DAC, known as Mod GRF 1-29, acts briefly and imitates the natural pulses of the hormone, but calls for several injections a day.
Beyond the pace of action both variants share the same status: neither is an approved medicine and both are prohibited in sport. The broader context is given in the pillar article on how peptides stimulate growth hormone release.
What does DAC in the name CJC-1295 mean?
DAC stands for drug affinity complex. In practice it is a linker attached to the CJC-1295 molecule. After subcutaneous injection the linker binds permanently to circulating albumin, a plasma protein. Because of this the peptide is not cleared quickly from the blood and acts for many days.
How does CJC-1295 with DAC work?
CJC-1295 with DAC keeps the GHRH receptor stimulated continuously for several days. The effect is a raised average level of growth hormone across the day and a sustained rise in IGF-1 concentration, lasting 9 to 11 days after a single dose. Because the action lasts so long, it is usually given once or twice a week.
How does CJC-1295 without DAC, that is Mod GRF 1-29, work?
The variant without the linker has a plasma half-life on the order of 30 minutes. The peptide occupies the receptor only in the window around the injection, which imitates the natural, pulsatile pattern of growth hormone release rather than holding the level permanently raised. To coincide with the natural peaks it is given several times a day, usually just before sleep.
CJC-1295 with and without DAC: a table of differences
| Feature | CJC-1295 with DAC | CJC-1295 without DAC (Mod GRF 1-29) |
|---|---|---|
| Half-life | about 6 to 8 days | about 30 minutes |
| Effect on growth hormone | steady, raised level for several days | a short pulse around the injection |
| Rise in IGF-1 after a dose | lasts 9 to 11 days | short-lived |
| Frequency of dosing | once or twice a week | several times a day, usually before sleep |
| Medicine and sport status | unapproved, prohibited in sport | unapproved, prohibited in sport |
What is known from human studies of CJC-1295?
The human data are very thin. They amount to a single phase one study from 2006. For neither form has a completed phase two or phase three trial assessed effectiveness.
CJC-1295 is not approved by the United States Food and Drug Administration. It was placed on the 503A list in category two, barred from pharmacy compounding. Both versions also appear on the World Anti-Doping Agency list in category S2. In this shop CJC-1295 is stocked as research material: CJC-1295, CJC-1295 with DAC and Mod GRF 1-29. The terms of purchase are set out on the legal warning page.
Frequently asked questions
How does CJC-1295 with DAC differ from Mod GRF 1-29?
CJC-1295 with DAC acts for 6 to 8 days and maintains a steady level of growth hormone, so it is given once or twice a week. Mod GRF 1-29 acts for about 30 minutes, imitates the natural pulses and calls for several injections a day.
What does the DAC linker do?
After injection it binds the CJC-1295 molecule permanently to plasma albumin. Because of this the peptide is not cleared quickly from the blood and acts for many days instead of minutes.
Are there human studies of CJC-1295?
Only one phase one study, from 2006. There are no completed phase two or phase three trials for either form.
Is CJC-1295 allowed in sport?
It is not. Both versions are on the World Anti-Doping Agency list in category S2 and are prohibited at all times.
Where this information comes from
The data on the DAC mechanism, the half-lives of 6 to 8 days and about 30 minutes, the effect on growth hormone and IGF-1 and the frequency of dosing come from material published by Superpower, version of 2 August 2026. The same material gives the status of CJC-1295: one phase one study from 2006, no completed phase two or three trials, the FDA 503A list in category two and the World Anti-Doping Agency list in category S2. The page was checked on 31 August 2026.