Growth Hormone · GHRH Analogue · Modified GRF 1-29

CJC-1295 (No DAC)

Tetrasubstituted GHRH(1-29) analogue with enhanced enzymatic stability. Studied for pulsatile GH release via somatotroph GHRH receptor binding. Frequently paired with GHSR agonists for synergistic research protocols.

HPLC Purity
99.3% Batch AV-2025-CJC-033
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Molecular Specifications
CAS Number863288-34-0
OriginGHRH(1-29) tetrasubstituted
ModificationsD-Ala²/Gln⁸/Ala¹⁵/Leu²⁷
Molecular Weight~3367 Da
Residues29 amino acids
TargetGHRH receptor (GHRHR)
Plasma Half-Life~30 minutes
FormLyophilised powder
Our Purity≥99.3% (RP-HPLC)

Mechanism of Action

CJC-1295 without DAC (Drug Affinity Complex), also called "Modified GRF 1-29" or "Mod GRF 1-29", is a tetrasubstituted analogue of the first 29 amino acids of human GHRH. The four amino-acid substitutions (D-Ala² · Gln⁸ · Ala¹⁵ · Leu²⁷) confer resistance to proteolytic degradation while preserving full agonist activity at the GHRH receptor.

GHRH Receptor Engagement
CJC-1295 binds GHRHR on pituitary somatotrophs with native-like affinity. Gs-coupled activation drives cAMP elevation and somatotroph degranulation — preserving the physiological signal-transduction pathway of endogenous GHRH.
Pulsatile GH Architecture
Unlike CJC-1295 WITH DAC (which produces tonic GH elevation via albumin binding), the No-DAC version produces clean GH pulses that decline naturally. This preserves the physiological pulse architecture that somatostatin-mediated feedback regulates.
GHSR Synergy
GHRH (CJC-1295) and ghrelin-mimetics (Ipamorelin, GHRP-6) activate independent receptor systems. Combined administration produces synergistic — rather than additive — GH pulse amplitude, a foundational pairing in GH-axis research protocols.

Mechanism Steps

  1. Enzymatic Resistance via 4 Substitutions

    The D-Ala² substitution blocks DPP-IV cleavage. Gln⁸ resistance to asparagine deamidation, Ala¹⁵ resistance to trypsin-like proteases, and Leu²⁷ resistance to methionine oxidation. The combined modifications extend half-life from ~10 min (native GHRH) to ~30 min.

  2. cAMP-PKA Cascade

    GHRHR Gs-coupling drives adenylyl cyclase activation. Intracellular cAMP rises, activating PKA which phosphorylates CREB and triggers GH gene transcription alongside immediate degranulation of pre-formed GH.

  3. Pulse Termination via Somatostatin

    Unlike DAC-modified CJC-1295, the No-DAC version is rapidly cleared, allowing somatostatin negative-feedback to terminate the GH pulse. This preserves natural pulse architecture and avoids receptor desensitisation.

Research Overview

GH Axis Pulse Studies

In rodent and canine research, 100–300 mcg CJC-1295 No-DAC produces GH peaks within 30–45 minutes that return to baseline within 2–3 hours. Repeated daily administration over weeks maintained pulse amplitude without measurable somatotroph desensitisation in published protocols.

Refs: Ionescu M, Frohman LA, JCEM (2006); Sackmann-Sala L et al., Mol Cell Endocrinol (2011)

Combined GHRH/GHRP Research

Studies pairing CJC-1295 No-DAC with Ipamorelin or GHRP-6 demonstrate GH pulse amplitudes 3–5× higher than either compound alone. This synergistic profile underlies the widespread use of GHRH/GHRP combinations in GH-axis preclinical research.

Refs: Bowers CY et al., JCEM (2004)

CJC-1295 No DAC vs With DAC
CJC-1295 With DAC adds a maleimide group that covalently binds plasma albumin, extending half-life to ~8 days for sustained tonic GH elevation. CJC-1295 No DAC retains the four amino-acid substitutions without the DAC, producing pulsatile rather than tonic GH release. Most modern research protocols favour the No DAC version specifically to preserve physiological pulse architecture.

Certificate of Analysis — Batch AV-2025-CJC-033

Each batch is independently tested by a third-party ISO-accredited laboratory. The analysis below reflects Batch AV-2025-CJC-033, tested 28 February 2025.

CJC-1295 (No DAC) — Batch AV-2025-CJC-033
RP-HPLC (C18) · MS/ESI+
99.3%
Test Date: 28 Feb 2025 · Release Date: 06 Mar 2025
Test ParameterMethodSpecificationResultStatus
IdentityESI-MS / MS-MSMatches theoretical m/zConfirmed (3367 Da)PASS
Purity (HPLC)RP-HPLC C18, 210nm≥98.0%99.3%PASS
Water contentKarl Fischer≤8.0%5.7%PASS
Heavy metalsICP-MS≤10 ppm<2 ppmPASS
EndotoxinsLAL chromogenic≤10 EU/mg<1 EU/mgPASS
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Full certificate includes raw chromatograms and mass spectra.

Storage & Reconstitution Protocol

FormTemperatureDuration
Lyophilised powder−20°C (preferred) or 2–8°C24 months / 12 months
Reconstituted (BAC water)2–8°C≤28 days
Reconstituted (saline)2–8°C≤7 days

Reconstitution Steps

  1. Aseptic Preparation

    Wipe vial with 70% IPA.

  2. Add Solvent

    For 2 mg vial, add 2 mL BAC water → 1 mg/mL stock. Inject slowly along the inner wall.

  3. Dissolve

    Swirl gently. CJC-1295 No-DAC is highly water-soluble; clear dissolution within 60 seconds.

  4. Refrigerate

    Store at 2–8°C. Avoid freeze-thaw of reconstituted solution.

Frequently Asked Questions

CJC-1295 With DAC produces tonic, sustained GH elevation (half-life ~8 days) which can desensitise somatotrophs and disrupt natural pulse architecture. The No DAC version produces clean pulses that decline naturally, allowing somatostatin feedback to maintain pulse integrity. Most modern research protocols favour No DAC for these physiological reasons.

The two compounds activate independent pituitary receptor systems: CJC-1295 stimulates GHRHR (Gs/cAMP pathway), Ipamorelin stimulates GHSR-1a (Gq/PLC pathway). Combined activation produces synergistic GH pulse amplitudes 3–5× greater than either compound alone — the foundational rationale for GHRH+GHRP pairings in research.

Most preclinical protocols administer pre-sleep (aligned with natural nocturnal GH pulse peak) or post-exercise (when growth hormone pulses are physiologically primed). Pre-meal fasted administration is preferred — elevated glucose and free fatty acids blunt the GH response via increased somatostatin tone.

Published preclinical data over multi-week daily administration did not show somatotroph desensitisation or pulse-amplitude attenuation. This contrasts with CJC-1295 With DAC, where sustained tonic GHRH receptor activation can produce receptor down-regulation. The No DAC version's clean pulse pattern is hypothesised to preserve receptor responsiveness.

Related Research Compounds

HPLC-Verified ≥99.3% · Batch-Tested · Cold-Chain Shipped

CJC-1295 (No DAC) — Research-Grade Supply

Independently verified by third-party ISO-accredited laboratory. COA available on request.

View CJC-1295 in Store → Reconstitution Protocol Guide