CJC-1295 (DAC)
Also known as CJC-1295 with DAC, DAC:GRF, Drug Affinity Complex GRF
CJC-1295 with DAC is a long-acting growth hormone releasing hormone analog that keeps growth hormone and IGF-1 elevated for about a week per injection. People use it for a steady rise in IGF-1 with only once or twice weekly dosing.
Overview
CJC-1295 with DAC is the original ConjuChem compound. It takes the same modified GRF 1-29 sequence and adds a drug affinity complex, a reactive maleimide group that covalently binds to albumin in the bloodstream within minutes of injection. Once attached to albumin, the peptide is shielded from kidney clearance and enzymatic breakdown, giving it a half-life of roughly six to eight days. One injection can raise mean growth hormone and IGF-1 for a week or more, which is a completely different pharmacological profile from the short pulse of the no DAC version.
The compound was tested in healthy adults in the mid 2000s. Single injections of 60 to 90 mcg per kg increased mean plasma growth hormone two to ten fold for about six days and raised IGF-1 by 1.5 to 3 fold for up to 11 days. Repeated weekly or biweekly dosing kept IGF-1 elevated throughout. Importantly, the pituitary continued to release growth hormone in pulses even under this constant stimulation, so the pattern was amplified rather than flattened. Development stalled after a serious cardiac event in a trial participant that was never firmly attributed to the drug, and the program was later abandoned.
For the research community, the DAC version is a trade-off. It is convenient and raises IGF-1 reliably with far fewer injections. The downside is that growth hormone stays elevated around the clock, including during meals, which some people worry blunts the normal feedback loop and increases side effects like water retention and numbness. There is no long term safety data in humans beyond the early trials, and no body composition outcome trials at all.
How it works
After injection, the DAC group forms a covalent bond with cysteine 34 on circulating albumin. The albumin bound peptide then acts as a slow reservoir of GHRH receptor agonist, continually stimulating somatotrophs in the pituitary to synthesize and release growth hormone. Because albumin is recycled rather than filtered, the complex persists for days. The pituitary still responds to somatostatin and ghrelin signals, so growth hormone pulses continue, but the baseline between pulses is higher and each pulse is larger. The elevated growth hormone drives the liver to produce more IGF-1, which is the main marker people track when using it.
What the research shows
- human RCTA single subcutaneous dose raised mean growth hormone 2-10 fold for about 6 days and IGF-1 1.5-3 fold for up to 11 days in healthy adults.
- human RCTGrowth hormone secretion remained pulsatile during continuous CJC-1295 stimulation, with increased pulse amplitude rather than loss of rhythm.
- human RCTEstimated half-life of 5.8 to 8.1 days after subcutaneous injection, consistent with albumin binding.
- human RCTWeekly and biweekly dosing kept IGF-1 elevated with no accumulation beyond steady state over 28 days.
Evidence labels: rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
Dosing and protocol
commonly split into 1-2 injections per week; some start at 500 mcg to assess tolerance
8-12 weeks, then reassess with IGF-1 bloodwork
Timing relative to meals matters much less than with the no DAC version because release is continuous. Many people inject in the evening.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 2 mg | 1 mL | 2 mg/mL | 50 units |
| 5 mg | 2 mL | 2.5 mg/mL | 40 units |
Lyophilized: freezer or fridge, away from light. Reconstituted: fridge 2-8C, use within 4 weeks.
Cautions
- ▲Continuous growth hormone elevation can cause water retention, puffy hands and face, and carpal tunnel like tingling; lower the dose if these appear.
- ▲Head rush and flushing right after injection are common, especially at the first few doses.
- ▲Because it lingers for a week, side effects cannot be stopped quickly by simply skipping a dose.
- ▲Raising IGF-1 for weeks at a time is inappropriate for anyone with active or prior hormone sensitive cancer.
- ▲Do not confuse it with the no DAC version; the dosing and frequency are completely different.
Commonly stacked with
Frequently asked
What does DAC actually do?
DAC stands for drug affinity complex. It is a chemical group that grabs onto albumin in your blood, so the peptide rides along with albumin for days instead of being cleared in minutes. That is what turns a 30 minute peptide into a once a week one.
Is the DAC or no DAC version better?
It depends on what you want. The DAC version is convenient and raises IGF-1 steadily with one or two shots a week. The no DAC version keeps growth hormone pulsatile and lets you time doses around sleep and fasting, which many people believe gives better results with fewer side effects.
How much will it raise IGF-1?
In the original trials, healthy adults saw IGF-1 rise 1.5 to 3 fold depending on dose. Individual response varies a lot, so bloodwork before and about 4 weeks in is the only way to know your own number.
Why was the drug discontinued?
ConjuChem paused development after a participant in a trial had a serious cardiac event. It was not clearly linked to the drug, but the company shifted priorities and the program never reached late stage trials.
References
- Prolonged stimulation of growth hormone and IGF-1 secretion by CJC-1295, a long-acting analog of GHRH, in healthy adults. Journal of Clinical Endocrinology and Metabolism, 2006
- Pulsatile secretion of growth hormone persists during continuous stimulation by CJC-1295. Journal of Clinical Endocrinology and Metabolism, 2006
- Drug affinity complex technology for extending peptide half-life via albumin conjugation. Bioconjugate Chemistry, 2005