CJC-1295 (no DAC) / Mod GRF 1-29
Growth Hormone Secretagogue (GHRH Analog)researchAlso known as: Mod GRF 1-29, Modified GRF (1-29), CJC-1295 without DAC, Tetrasubstituted GRF 1-29
A modified growth hormone-releasing hormone fragment with a short half-life (~30 minutes) that stimulates pulsatile growth hormone release, closely mimicking the body's natural GH secretion pattern.
Overview
CJC-1295 without DAC, commonly called Mod GRF 1-29 (Modified Growth Hormone-Releasing Factor, amino acids 1-29), is a synthetic GHRH analog that has been modified at four amino acid positions to resist enzymatic degradation while maintaining a relatively short half-life of approximately 30 minutes. Unlike the DAC version which creates sustained GH elevation, the no-DAC version produces discrete GH pulses that more closely mimic the body's natural pulsatile GH secretion pattern. This is considered physiologically preferable by many practitioners. It is most commonly used in combination with growth hormone-releasing peptides (GHRPs) like ipamorelin, as GHRH and GHRP work synergistically — GHRH amplifies the GH pulse while GHRP initiates it. This combination is often called the 'CJC/Ipa stack' and is one of the most popular peptide protocols in the anti-aging and performance community.
Mechanism of Action
Mod GRF 1-29 works by: (1) Binding to GHRH receptors on somatotroph cells in the anterior pituitary; (2) Amplifying the magnitude of growth hormone pulses without significantly altering pulse frequency; (3) Working synergistically with endogenous ghrelin or exogenous GHRPs — GHRP initiates the GH pulse and GHRH amplifies it; (4) The four amino acid substitutions (Ala2→D-Ala, Asn8→Gln, Ala15→Ala(Me), Met27→Leu) protect against DPP-IV cleavage and oxidation; (5) Short half-life allows for pulsatile dosing that preserves natural GH rhythm and feedback sensitivity.
Molecular Formula
C152H252N44O42
Molecular Weight
3367.9 g/mol
Sequence
Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala(Me)-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH2
Dosage Protocols
Dose Range
100mcg – 100mcg
Frequency
1-3 times daily
Route
subcutaneous
Cycle Length
8-12 weeks on, 4 weeks off
Most commonly dosed at 100mcg per injection alongside 100-200mcg ipamorelin. Best taken before bed on an empty stomach (2+ hours fasted) to coincide with natural nocturnal GH pulse. Can also dose upon waking and/or post-workout.
Source: Clinical guidance and community protocols
Side Effects
| Effect | Severity |
|---|---|
| Flushing | mild |
| Injection site irritation | mild |
| Headache | mild |
| Dizziness | mild |
| Water retention | mild |
| Increased hunger | mild |
Pros & Cons
Mimics natural pulsatile GH release pattern — more physiological than DAC version or exogenous HGH
Excellent synergy with GHRPs (especially ipamorelin) — the combination is greater than either alone
Fewer side effects than DAC version due to short-acting nature
Preserves natural GH feedback mechanisms and pituitary sensitivity
Flexible dosing allows targeting specific GH pulses (sleep, post-workout)
Requires multiple daily injections for optimal results (less convenient than DAC version)
Must be taken in fasted state (2+ hours post-meal) for effective GH release
Less effective when used alone — really needs to be paired with a GHRP
Not FDA-approved; quality depends on source
GH elevation is more modest compared to direct HGH administration
Research Studies
Legal Status
Not FDA-approved. Available as a research chemical. Banned by WADA for competitive athletes.
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