CJC-1295 (no DAC)
Also known as Mod GRF 1-29, Modified GRF 1-29, CJC-1295 without DAC, Tetrasubstituted GRF 1-29
CJC-1295 without DAC, better known as Mod GRF 1-29, is a short-acting analog of growth hormone releasing hormone. People use it to prompt a natural-looking pulse of growth hormone, almost always paired with a GHRP like ipamorelin.
Overview
Mod GRF 1-29 is a 29 amino acid fragment of human growth hormone releasing hormone (GHRH) with four amino acid substitutions that make it resist enzymatic breakdown. The name CJC-1295 originally belonged to a drug candidate from ConjuChem that included a drug affinity complex (DAC) to extend its half-life for days. The version sold without that complex is the same core sequence with no DAC attached, so its action is short and closely mimics a natural GHRH pulse. Most vendors label it CJC-1295 no DAC, while the research community usually calls it Mod GRF 1-29.
The substitutions (D-Ala at position 2, Gln at 8, Ala at 15, and Leu at 27) were designed to block cleavage by DPP-IV and other peptidases while preserving strong binding at the GHRH receptor. The result is a compound that produces a larger and more reliable growth hormone release than native GHRH or sermorelin, but still clears within about half an hour. That short window is exactly why people prefer it over the DAC version when the goal is to keep growth hormone pulsatile rather than continuously elevated.
Direct human trial data on Mod GRF 1-29 as a standalone product is thin. Most of what we know comes from older studies on tetrasubstituted GRF analogs and from the general GHRH literature, plus the pharmacology of the DAC version, which was tested in healthy adults. The consistent picture is that GHRH analogs raise growth hormone and IGF-1 in a dose dependent way, and that combining a GHRH analog with a GHRP produces a synergistic release larger than either alone. Long term outcome studies on body composition with this specific compound do not exist.
How it works
Mod GRF 1-29 binds the GHRH receptor on somatotroph cells in the anterior pituitary, raising cyclic AMP and triggering synthesis and release of growth hormone. It only amplifies a pulse the pituitary is already capable of producing, which is why it works far better when somatostatin tone is low, such as in a fasted state or during the early hours of sleep. Because it does not touch the ghrelin receptor, it does not increase hunger or cortisol on its own. When taken alongside a GHRP, the two pathways combine to yield a growth hormone spike that is typically several times larger than either agent alone.
What the research shows
- in vitroTetrasubstituted GRF 1-29 analogs resist DPP-IV degradation and retain full potency at the GHRH receptor in laboratory assays.
- human pilotGHRH analogs combined with a GHRP produce a synergistic growth hormone release in humans that exceeds the sum of each alone.
- human RCTGHRH receptor agonists increase pulsatile growth hormone and downstream IGF-1 in healthy adults in a dose dependent manner.
- human pilotShort-acting GHRH analogs preserve the normal pulsatile pattern of growth hormone secretion rather than flattening it.
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
100 mcg is often called a saturation dose; going higher adds little extra release
8-16 weeks, then a break of a few weeks
Fasted, at least 2 hours after a meal, and most often right before bed. Avoid eating for 20-30 minutes after injecting.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 4 units |
| 10 mg | 3 mL | 3.333 mg/mL | 3 units |
Lyophilized: freezer or fridge, away from light. Reconstituted: fridge 2-8C, use within 4 weeks.
Cautions
- ▲Flushing, warmth, and a brief head rush shortly after injection are common and usually fade within minutes.
- ▲Taking it with food or a sugary drink blunts the growth hormone response, so timing matters more than dose.
- ▲Water retention, tingling in the hands, and mild joint aches can appear if doses are pushed high or stacked aggressively.
- ▲Anyone with an active cancer or a history of hormone sensitive tumors should avoid raising IGF-1.
- ▲It is frequently confused with the DAC version; make sure the vial you buy matches the protocol you plan to run.
Commonly stacked with
Frequently asked
Is CJC-1295 no DAC the same thing as Mod GRF 1-29?
Yes. They are the same 29 amino acid sequence with the same four substitutions. Mod GRF 1-29 is the more accurate name because CJC-1295 technically refers to the version with the drug affinity complex attached.
Why do people always pair it with ipamorelin?
GHRH analogs and GHRPs act on two different receptors, and together they produce a growth hormone pulse much larger than either alone. Ipamorelin is the usual partner because it adds the synergy without raising cortisol, prolactin, or hunger.
How long before bed should I take it?
Most protocols inject right before sleep on an empty stomach, since the biggest natural growth hormone pulse happens in the first hours of deep sleep. Eating within 30 minutes on either side of the shot reduces the response.
Does it need to be cycled?
There is no strong evidence of receptor desensitization with GHRH analogs, but most community protocols run 8-16 weeks and then pause for a few weeks. Bloodwork on IGF-1 is the practical way to see whether it is still doing anything.
References
- Prolonged stimulation of growth hormone and IGF-1 secretion by CJC-1295, a long-acting GHRH analog, 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
- Synergistic effects of GHRH and GHRPs on growth hormone secretion in humans. Endocrine Reviews, 1997