MOD GRF 1-29 vs CJC-1295: Naming Guide

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MOD GRF 1-29 vs CJC-1295: Naming Guide
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CategoryComparisons
Also known asMOD GRF vs CJC-1295, CJC-1295 vs MOD GRF, Are MOD GRF and CJC-1295 the same, GHRH peptide naming
Last updated2026-04-22
Reading time5 min read
Tags
comparisongrowth-hormoneghrhcjc-1295mod-grfnaming

TL;DR

  • MOD GRF 1-29 = the modified GHRH(1-29) fragment, with four amino acid substitutions for stability.
  • CJC-1295 (no DAC) = the same molecule. Different name, identical compound.
  • CJC-1295 with DAC = MOD GRF 1-29 + Drug Affinity Complex (DAC). Different molecule, very different pharmacokinetics.
  • The shorthand: "MOD GRF 1-29" and "CJC-1295" without the DAC suffix are the same thing. Add DAC and it becomes a different drug entirely.

If you only remember one thing: when you read "CJC-1295," check whether the seller says "with DAC" or "without DAC." Without DAC, it's MOD GRF 1-29. With DAC, it's the long-acting weekly version.

The headline difference, in one sentence

There are really only two products here despite three names: the short-acting peptide (MOD GRF 1-29 = CJC-1295 no DAC) and the long-acting peptide (CJC-1295 with DAC).

Half-life: there are really only two products here

log scale (values span orders of magnitude)

MOD GRF 1-29 (= CJC-1295 no DAC)
30 min
CJC-1295 with DAC
7.0 days

The naming history, briefly

Researchers wanted a more stable version of GHRH(1-29) — the active fragment of natural GHRH. They made four amino-acid substitutions to resist enzymatic breakdown. That stabilized fragment is MOD GRF 1-29 (literally: modified growth-releasing factor, residues 1-29).

Then a company called ConjuChem developed two versions of this molecule:

  • One was the bare modified fragment — they called it CJC-1295.
  • The other was the same fragment with a Drug Affinity Complex attached. The DAC is a maleimide group that binds to circulating albumin, dramatically extending half-life. They called this CJC-1295 with DAC or sometimes CJC-1293 in early literature.

Over time, the research-supply market started using "MOD GRF 1-29" to refer specifically to the no-DAC version (because saying "CJC-1295 without DAC" every time is awkward), and "CJC-1295" alone usually meant the with-DAC version. But not always. Hence the confusion.

What you'll see in the wild

Label you might seeWhat it actually is
"MOD GRF 1-29"Short-acting peptide, no DAC
"CJC-1295 (no DAC)"Same as above
"CJC-1295 without DAC"Same as above
"CJC-1295 DAC"Long-acting peptide, with DAC
"CJC-1295 (DAC)"Same as above
"CJC-1295 with DAC"Same as above
"CJC-1293"Older name, usually means with-DAC version
Just "CJC-1295" with no DAC clarificationAmbiguous — ask the supplier

If a vendor sells both "MOD GRF 1-29" and "CJC-1295" as separately-priced products without saying "with DAC" on the second one, that's a red flag. They might be selling the same molecule twice with different markup.

How they actually behave

This is where they really diverge:

FeatureMOD GRF 1-29 (CJC-1295 no DAC)CJC-1295 with DAC
Half-life~30 minutes~6–8 days
Dosing frequency2–3x dailyWeekly
GH release patternPulsatileSustained
Best paired withIpamorelin for combined pulsesIpamorelin, but pulse logic breaks down
Side effect profileCleanerMore flushing, water retention

The mechanism is otherwise identical — both bind the GHRH receptor on the pituitary. DAC just makes the peptide hang around in circulation longer.

For a deeper comparison of the two pharmacokinetic profiles, see CJC-1295 with DAC vs without DAC.

Pick the no-DAC version (MOD GRF 1-29) if...

  • You want physiologic GH pulses that mimic natural release.
  • You're building a classic GHRH + GHRP stack with Ipamorelin.
  • You're willing to inject 2–3x daily for maximum effect.
  • You want a cleaner side-effect profile.

Pick the DAC version if...

  • Once-weekly dosing convenience is the deciding factor.
  • The research target is sustained IGF-1 elevation rather than physiological GH pulses.
  • You accept the trade-off of GH "bleed" instead of pulses, and the typically more pronounced side effects.

Honest tradeoffs

  • Naming is a minefield: when buying or reading research, always confirm whether you're talking about the with-DAC or no-DAC version. They behave very differently.
  • Stacking math: pairing a short-acting peptide (Ipamorelin) with a long-acting peptide (CJC-1295 with DAC) means the GHRP pulses but the GHRH is constant — different from the classic pulse-pulse stack.
  • Stability: both versions are typical lyophilized peptides; reconstitute with bacteriostatic water, refrigerate after mixing.
  • Cost per cycle: MOD GRF 1-29 is generally cheaper per dose but you use more of it. CJC with DAC is pricier per vial but lasts longer per injection. Total cost-per-week tends to be similar.

Quick decision shortcut

Your questionProbably go with
"I want natural GH pulses."MOD GRF 1-29
"I want one injection per week."CJC-1295 with DAC
"I want to pair with ipamorelin properly."MOD GRF 1-29
"I want sustained IGF-1 elevation."CJC-1295 with DAC
"Vendor just lists 'CJC-1295' with no DAC info."Ask the vendor, don't assume

Where to read more

Important context

These are research peptides without FDA approval for any indication. Pre-clinical and limited human trial data exist. Nothing on this page is medical advice.

Related entries

  • CJC-1295 with DACA long-acting growth hormone-releasing hormone analog featuring a Drug Affinity Complex that extends its half-life to approximately 6-8 days through albumin binding, enabling sustained GH and IGF-1 elevation.
  • CJC-1295A synthetic analog of growth hormone releasing hormone (GHRH) available in two forms — with and without Drug Affinity Complex (DAC) — studied for sustained stimulation of pituitary GH secretion.
  • IpamorelinA selective growth hormone secretagogue pentapeptide that stimulates GH release from the pituitary with minimal effects on cortisol, prolactin, and appetite compared to other GHRPs.
  • Mod GRF 1-29A modified 29-amino-acid fragment of growth hormone-releasing hormone (GHRH) with four amino acid substitutions for improved metabolic stability, commonly paired with GH-releasing peptides to stimulate pulsatile growth hormone secretion.
  • SermorelinA 29-amino-acid synthetic analog of growth hormone releasing hormone (GHRH) with a history of FDA approval, studied for age-related GH decline, pediatric growth deficiency, and anti-aging applications.