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Experimental/GH SecretagogueResearch peptide

Modified GRF(1-29)

aka CJC-1295 no-DAC · Mod GRF 1-29

Short-acting GHRH analog without the DAC linker, producing pulsatile GH release.

Educational explainer of a research peptide. Profiles in this section deliberately omit clinical-trial citations, dosing protocols, and purchase links. Not FDA-approved as a supplement; not a recommendation to use.

Overview

A tetra-substituted GHRH(1-29) analog that resists DPP-IV degradation but lacks the albumin-binding DAC linker of full CJC-1295, giving a half-life of ~30 minutes.

Source
  • Synthesized in research laboratories
Forms
  • Subcutaneous injection

Mechanism of action

Binds pituitary GHRH receptors to drive a brief, physiologic GH pulse that respects somatostatin feedback.

Pathways
  • · GHRH receptor
  • · cAMP-PKA
  • · GH gene transcription
Hormones
  • · GH
  • · IGF-1

How it acts on the body

Modified GRF(1-29) was designed to keep the receptor activity of native GHRH while resisting the DPP-IV cleavage that normally inactivates it within minutes. The result is a peptide that still produces a discrete, somatostatin-modulated GH pulse rather than the flat elevation seen with DAC-linked CJC-1295.

Because pulses respect endogenous negative feedback, downstream IGF-1 rises modestly rather than supraphysiologically, which is the rationale for stacking it with a GHRP rather than chasing higher doses alone.

Hormonal & endocrine impact

How this peptide is reported to shift specific hormones and signaling molecules. Directionality reflects research literature and preclinical models, not clinical prescribing data.

Projected hormonal trajectory
Illustrative curves derived from reported direction of effect. Not measured patient data.

Curves are schematic shapes (sigmoid for increases/decreases, damped oscillation for modulation/stabilization) anchored to a 100% baseline. They communicate direction and tempo of change reported in research literature — not absolute hormone concentrations.

GHIncreases
Brief pulse mirroring physiologic GHRH release.
IGF-1Increases
Modest rise from repeated pulses.
SomatostatinModulates
Feedback remains intact, preventing supraphysiologic spikes.

Effects on the body

Increases
Endogenous GH pulse amplitude
Supports
Recovery and body composition over months

Organ system effects

Liver

Mediates IGF-1 production in response to GH pulses.

Skeletal Muscle

Indirect anabolic and recovery support.

Endocrine

Acts at the pituitary somatotrophs.

Reported effects

Drawn from preclinical research, anecdote, and small-scale clinical observation. No evidence grades are assigned — most peptides on this page lack rigorous human trials.

  • Preserves physiologic GH pulsatility
  • Lower IGF-1 ceiling than DAC variants

Potential side effects

Common
  • · Injection site flushing
  • · Transient lightheadedness
Rare
  • · Water retention
  • · Numbness
Serious
  • · Carpal tunnel symptoms with chronic high-dose use

Drug interactions

Glucocorticoids
Blunt GH response.
moderate

Pairing context

Often combined with
  • Ipamorelin or GHRP-2
    Synergistic pulse via complementary receptors.
Avoid combining with
  • Active malignancy
    GH/IGF-1 axis stimulation is contraindicated.
Important. Research peptides described here are not FDA-approved supplements. Supplement Scholar does not endorse, recommend, or link to any source for purchase. Consult a qualified clinician before considering any peptide therapy.