“CJC-1295” is one of the most confusing names in the peptide world because it’s used for two different compounds. One lasts about a week in the body. The other lasts about half an hour. Mixing them up leads to a lot of bad information. Here’s how to tell them apart.
Key takeaways
- Both are synthetic analogs of growth hormone–releasing hormone (GHRH).
- CJC-1295 with DAC binds to albumin in the blood and had a half-life of roughly 6 to 8 days in early human studies.
- CJC-1295 without DAC, also called Modified GRF (1-29), has a half-life of roughly 30 minutes.
- Neither is FDA-approved, and neither has an established human dose.
Background: what is GHRH?
Growth hormone–releasing hormone is made by the hypothalamus in the brain. It signals the pituitary gland to release growth hormone (GH) in pulses, mostly during deep sleep. GH then prompts the liver to make IGF-1, which drives many of GH’s effects on tissue.
Only the first 29 amino acids of GHRH are needed for activity. That fragment, GRF (1-29), is the starting point for both versions of CJC-1295. It’s also essentially what sermorelin is. See our GH secretagogues guide for the full family.
What “DAC” means
DAC stands for Drug Affinity Complex. It’s a chemical attachment that lets the peptide bond to albumin, the most common protein in blood. Albumin circulates for weeks, so a peptide riding on it avoids being quickly broken down or filtered out.
Both versions also include four amino acid substitutions that make the peptide more resistant to DPP-4, the enzyme that rapidly breaks down natural GHRH.
Side-by-side comparison
| CJC-1295 with DAC | CJC-1295 without DAC (Mod GRF 1-29) | |
|---|---|---|
| Structure | Modified GRF (1-29) + DAC linker | Modified GRF (1-29) only |
| Half-life | ~6–8 days in early human studies | ~30 minutes |
| GH pattern | Sustained elevation over days | Short pulse, closer to natural release |
| Human research | Small early-phase studies in healthy adults (mid-2000s) | Very limited |
| Development | Clinical development discontinued | Never developed as an approved drug |
| FDA status | Not approved | Not approved |
| WADA status | Prohibited (S2) | Prohibited (S2) |
What the human studies found (with DAC)
Early studies in healthy adults, published in 2006, found that a single injection of CJC-1295 with DAC raised GH levels several-fold for six days or more and raised IGF-1 for over a week. Pulsatile GH release appeared to be preserved, with a higher baseline. These were small, short studies designed to test safety and drug behavior, not long-term benefit. Clinical development was later stopped.
Why the difference matters
- Research design: a compound that lasts a week and one that lasts half an hour can’t be studied the same way. Timing, frequency and measured outcomes all differ.
- Physiology: the body naturally releases GH in pulses. A sustained elevation (with DAC) is a different signal from a short pulse (without DAC), and the long-term effects of either haven’t been established.
- Labeling confusion: products sold simply as “CJC-1295” may be either one. Check the full name and the mass spec result on the COA, since the two have very different molecular weights.
Why it’s often paired with ipamorelin
GHRH analogs and ghrelin mimetics like ipamorelin act on different receptors. In physiology research, combining the two pathways produces a larger GH response than either alone. That’s the rationale behind the popular CJC-1295/ipamorelin pairing. It’s a reasonable pharmacology idea, but there are no controlled long-term trials of the combination.
Safety considerations
- Early studies reported injection-site reactions, flushing, headache and temporary water retention.
- Raising GH and IGF-1 can reduce insulin sensitivity and affect blood sugar.
- Long-term effects of sustained GH/IGF-1 elevation, including effects on existing tumors, are unknown for these compounds.
Dosing
Following Pep Guide’s policy, we don’t list doses for CJC-1295 in either form. Neither version has an FDA label or adequate human trials establishing a dose.
Related: Stacks & Tracking · Compound Library
Frequently asked questions
What is the difference between CJC-1295 DAC and no DAC?
With DAC, the peptide binds to albumin and lasts about a week. Without DAC (Mod GRF 1-29), it lasts about 30 minutes and produces a short growth hormone pulse.
Is Mod GRF 1-29 the same as CJC-1295?
Mod GRF 1-29 is CJC-1295 without DAC. The terms are often used interchangeably for the no-DAC version.
Is CJC-1295 the same as sermorelin?
No, but they are related. Sermorelin is GRF (1-29) without modifications. CJC-1295 adds amino acid substitutions for stability, and the DAC version adds an albumin-binding group.
Is CJC-1295 FDA-approved?
No. Neither version of CJC-1295 is approved by the FDA.
Medical disclaimer: Pep Guide is for educational purposes only. It is not medical advice, diagnosis or treatment. Research changes over time. Talk to a licensed healthcare provider before starting, stopping or changing any medication or compound.