CJC-1295 Without DAC (MOD GRF 1-29) is a tetrasubstituted GHRH(1-29) analog with ~30-minute half-life — the preferred short-acting GHRH analog for pulsatile GH research protocols, commonly paired with ipamorelin.
Product definition
What is CJC-1295 Without DAC?
CJC-1295 Without DAC (MOD GRF 1-29) is a tetrasubstituted GHRH(1-29) analog with ~30-minute half-life — the preferred short-acting GHRH analog for pulsatile GH research protocols, commonly paired with ipamorelin.
CJC-1295 Without DAC (also called MOD GRF 1-29, Modified GRF(1-29), or tetrasubstituted GHRH(1-29)) is a synthetic GHRH analog engineered with four protective amino acid substitutions at positions 2 (Ala→Aib), 8 (Ala→Gln), 15 (Gly→Ala), and 27 (Met→Nle). These modifications address the principal enzymatic degradation pathways of native GHRH(1-29):
- Position 2: Aib (α-aminoisobutyric acid) substitution prevents DPP-IV cleavage, the primary inactivation pathway
- Position 8: Gln substitution protects against neutral endopeptidase cleavage
- Position 15: Ala substitution reduces amide backbone hydrolysis susceptibility
- Position 27: Nle substitution prevents methionine oxidation
The combined effect of these substitutions extends the in vivo half-life from approximately 2 minutes (native GHRH) to approximately 30 minutes without altering GHRH receptor binding affinity or downstream GH secretion kinetics. The compound retains full receptor agonism while gaining pharmacokinetic stability — the fundamental engineering objective.
Research context
How is CJC-1295 Without DAC described in the research literature?
CJC-1295 Without DAC binds GHRH receptors with full agonism, stimulating pulsatile GH release via cAMP signaling in pituitary somatotropes. Four protective amino acid substitutions extend half-life from ~2 min (native GHRH) to ~30 min, enabling consistent somatotrope activation with physiologically patterned GH pulses. Synergistic with GHRPs (ipamorelin) via independent receptor systems.
Compound profile
Key facts about CJC-1295 Without DAC
- Class
- Modified GHRH analog (tetrasubstituted GHRH(1-29))
- Also known as
- MOD GRF 1-29, Modified GRF(1-29)
- Amino acids
- 29 (with 4 protective substitutions)
- Molecular weight
- ~3,367 Da
- Half-life
- ~30 minutes in vivo
- Research category
- GH axis, pulsatile GH research, GHRH pharmacology
- Common pairing
- Ipamorelin (2X Blend) for synergistic GH pulse amplification
- Storage
- Lyophilized: −20°C. Reconstituted: 2–8°C, use within 30 days
Research areas
What research areas is CJC-1295 Without DAC associated with?
- ~30-minute half-life via 4 protective substitutions — full GHRH receptor agonism with dramatically improved stability vs native GHRH
- Produces physiologically patterned pulsatile GH release — preserves GH secretion dynamics critical to anabolic and metabolic research
- Most widely used short-acting GHRH analog in GH secretagogue research protocols
- Synergistic with ipamorelin and other GHRPs via mechanistically independent receptor systems (2X Blend combination)
- DPP-IV resistant — position-2 Aib substitution removes the primary GHRH inactivation mechanism
- Reference GHRH component for pulsatile GH protocol research, comparative GHRH pharmacology
Research audience
Who researches CJC-1295 Without DAC?
CJC-1295 Without DAC is used by researchers studying GH pulse physiology, GHRH receptor pharmacology, GH secretagogue combination protocols, and pituitary somatotrope activation. It is the standard GHRH component in research protocols requiring pulsatile GH release without the sustained GH elevation profile of CJC-1295 With DAC.
Preclinical research overview
What does the preclinical literature say about CJC-1295 Without DAC?
The nomenclature history of this compound is worth understanding for research literature navigation. 'CJC-1295' was originally applied by ConjuChem Inc. to their tetrasubstituted GHRH(1-29) before the Drug Affinity Complex (DAC) modification was added. When the DAC modification was developed, the albumin-binding version became 'CJC-1295 With DAC' and the original version was retroactively called 'CJC-1295 Without DAC.' The underlying unmodified-by-DAC peptide is correctly designated MOD GRF 1-29 or GRF(1-29)NH2 in pharmacological literature — both names refer to the same molecule.
In GH secretagogue research, CJC-1295 Without DAC is most commonly studied in combination with a GHRP (ipamorelin being the most common due to its selectivity profile). Multiple animal model studies have documented that the GHRH+GHRP combination produces significantly greater GH release than either compound alone — the synergy attributable to GHRH's priming of somatotrope pool responsiveness and GHRP's amplification of GH release magnitude via the distinct GHS-R1a pathway.
For comparative protocol design, CJC-1295 Without DAC is the appropriate GHRH choice when the study requires pulsatile GH dynamics; CJC-1295 With DAC is the choice when sustained GH elevation over days is the protocol requirement.
Common questions
Frequently asked about CJC-1295 Without DAC
What is the difference between CJC-1295 With DAC and Without DAC?
The DAC modification is a maleimide-lysine conjugate that enables covalent albumin binding in vivo, extending half-life from ~30 minutes (Without DAC) to ~6–8 days (With DAC). Without DAC produces a sharp GH pulse each administration — preferred for pulsatile GH research. With DAC produces a sustained, blunted GH elevation over approximately one week — preferred for prolonged GH axis stimulation research. Neither is superior; they address different research questions.
Why is CJC-1295 Without DAC also called MOD GRF 1-29?
The two names refer to the identical molecule. MOD GRF 1-29 is the pharmacological designation. CJC-1295 Without DAC is the commercial designation that emerged from the ConjuChem development program. In searching the literature, 'Modified GRF(1-29)' or 'Mod GRF 1-29' will find pharmacokinetic studies; 'CJC-1295 Without DAC' will find research supply literature. Both point to the same tetrasubstituted GHRH(1-29) peptide.
What is the preferred GHRP to pair with CJC-1295 Without DAC?
Ipamorelin is the most common pairing because it is the most selective GHRP — producing GH release without significant cortisol or prolactin co-stimulation. This selectivity keeps the research endpoint clean: GH-specific effects are attributable to GH axis activation rather than mixed ACTH/cortisol/GH signaling. GHRP-2 is a more potent alternative when maximal GH response is required, but at the cost of significant cortisol co-stimulation that must be accounted for in the study design.
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