CJC-1295 MOD GRF 1-29 is a short-acting GHRH analog, also called modified GRF (1-29). Learn how it compares to DAC versions and what research shows.
CJC-1295 MOD GRF 1-29 is a synthetic growth hormone-releasing hormone (GHRH) analog built from the first 29 amino acids of GHRH with four structural changes. Researchers usually call it modified GRF (1-29) or MOD GRF, and suppliers often list it as the short-acting, "no DAC" form of CJC-1295. It has a half-life of roughly 30 minutes and is not FDA-approved for human use.
What Exactly Is CJC-1295 MOD GRF 1-29?
"CJC-1295" is a family name rather than a single molecule. It covers both a long-acting version and this short-acting fragment, and the "MOD GRF 1-29" label tells you which one you are reading about.
The peptide contains 29 amino acids and four substitutions: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. Those swaps block the DPP-IV enzyme from degrading the peptide within minutes, which is what makes it stable enough to study at all.
You will see it sold under several interchangeable names, including:
- Modified GRF (1-29)
- Tetrasubstituted GRF (1-29)
- CJC-1295 without DAC
- GRF (1-29) analog
The key point: CJC-1295 MOD GRF 1-29 and CJC-1295 DAC are two different molecules with very different half-lives.
MOD GRF 1-29 vs CJC-1295 DAC: The Core Difference
Most of the confusion around mod grf 1-29 vs cjc 1295 dac comes down to a single feature: the Drug Affinity Complex. That complex is a maleimide linker that attaches the peptide to serum albumin in the bloodstream.
A product sold as cjc-1295 with drug affinity complex circulates for roughly six to eight days because albumin acts as a carrier. A product sold as cjc-1295 without drug affinity complex is cleared within a couple of hours and produces a much sharper, shorter spike in growth hormone.
| Feature | CJC-1295 MOD GRF 1-29 (no DAC) | CJC-1295 DAC |
|---|---|---|
| Amino acids | 29 | 30 plus linker |
| Albumin binding | None | Yes, via maleimide linker |
| Approximate half-life | ~30 minutes | ~6 to 8 days |
| Typical research dosing frequency | Multiple times per day | Once weekly or less |
| GH release pattern | Pulsatile, closer to natural | Sustained elevation |
How MOD GRF 1-29 Works in the Body
MOD GRF 1-29 binds to GHRH receptors on pituitary cells and signals them to release growth hormone. It does not force GH out on its own; it amplifies the natural pulses the body already generates.
Because the peptide clears quickly, the resulting GH release is pulsatile rather than constant. That pattern is one reason researchers pair it with ghrelin-receptor agonists, which trigger GH through a separate pathway and can act synergistically.
Growth hormone released this way also drives IGF-1 production in the liver, which is why IGF-1 levels are a common endpoint in published studies.
What the Research Actually Shows
Human data on CJC-1295 exists mainly for the DAC version. A 2006 study in healthy adults found that a single dose raised growth hormone and IGF-1 levels for up to six days, and a separate trial looked at the compound in people with HIV-associated fat accumulation.
MOD GRF 1-29 itself has far less human data. Most of what is published comes from earlier work on GHRH (1-29) fragments in older adults, plus animal and laboratory studies. Anyone citing "proven" benefits for the short-acting version is going beyond the evidence.
Common Peptide Combinations in Research
MOD GRF 1-29 is rarely studied alone. Researchers typically combine it with a GH secretagogue to test whether the two pathways produce a larger response together.
- Ipamorelin — a selective ghrelin-receptor agonist with less effect on cortisol and prolactin than older GHRPs.
- GHRP-2, GHRP-6, and hexarelin — older secretagogues that raise hunger and stress hormones more noticeably.
- AOD-9604 — an HGH fragment (176-191) studied for fat metabolism, not a GH secretagogue at all.
For fat-loss research, aod-9604 vs cjc-1295 ipamorelin is a frequent comparison because the compounds act through completely different mechanisms. Newer protocols often combine cjc 1295 ipamorelin aod 9604 to examine GH release and lipid metabolism side by side.
| Peptide | Mechanism | Approximate half-life | Primary research focus |
|---|---|---|---|
| MOD GRF 1-29 | GHRH receptor agonist | ~30 minutes | Pulsatile GH release |
| Ipamorelin | Ghrelin receptor agonist | ~2 hours | Selective GH release |
| AOD-9604 | HGH fragment 176-191 | ~30 minutes | Fat metabolism |
Side Effects and Safety Considerations
Reported side effects in research and anecdotal settings include injection site irritation, flushing, headache, dizziness, water retention, and tingling or numbness in the hands. Increased hunger is common with less selective secretagogues.
Sustained elevations in growth hormone and IGF-1 carry theoretical risks, including insulin resistance, joint swelling, and tissue growth concerns. IGF-1 is a known mitogen, so long-term use is not something to take lightly.
CJC-1295 MOD GRF 1-29 is a research chemical, not a medication. Anyone considering it should talk with a licensed healthcare professional rather than relying on forum protocols.
Legal Status in the United States
The FDA has not approved CJC-1295 MOD GRF 1-29 for any human indication. It is legally sold only as a research chemical labeled "not for human use."
The peptide is not scheduled under the Controlled Substances Act, but the FDA has sent warning letters to vendors selling it for human consumption. Compounding pharmacies are generally barred from producing it without an approved application, which keeps the market in a gray zone.
The bottom line: CJC-1295 MOD GRF 1-29 is the short-acting, albumin-free GHRH analog, while CJC-1295 DAC is the long-acting version. Neither is FDA-approved for human use.
Frequently Asked Questions
Is CJC-1295 MOD GRF 1-29 the same as CJC-1295?
Not exactly. CJC-1295 MOD GRF 1-29 is the 29-amino-acid fragment without the Drug Affinity Complex, so it clears the body in about 30 minutes. Plain "CJC-1295" usually refers to the DAC version, which binds albumin and lasts six to eight days. They share a similar receptor target but behave very differently.
How long does CJC-1295 MOD GRF 1-29 stay in your system?
Its half-life is roughly 30 minutes, meaning most of the peptide is cleared within a few hours. That short window is why research protocols using the no-DAC form often involve multiple administrations per day. The DAC version, by contrast, remains active for about a week.
Is CJC-1295 MOD GRF 1-29 legal in the United States?
It is not FDA-approved for human use and is legally sold only as a research chemical. It is not a controlled substance under federal law, but the FDA has issued warning letters to sellers marketing it for human consumption. Buying it for personal injection use sits in a regulatory gray area.
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.