# MOD-GRF (1-29)

> Evidence tier C — Animal data · GH & Growth · reviewed 2026-11-08
> Source page: https://peptidemeta.com/p/mod-grf-1-29/

Also known as: Modified GRF (1-29), CJC-1295 without DAC, Tetrasubstituted GRF(1-29)

## Quick answers

**What is MOD-GRF (1-29)?**

A modified growth hormone releasing factor with four amino acid substitutions for improved stability and bioavailability. Same compound sold as "CJC-1295 no DAC": GHRH(1-29) with four amino-acid substitutions for stability.

**How strong is the evidence for MOD-GRF (1-29)?**

Tier C (animal data) on the peptidemeta evidence scale. Published data are mostly preclinical; no completed human trials of this compound were found.

**Is MOD-GRF (1-29) FDA-approved?**

No. MOD-GRF (1-29) is not approved by the FDA for any use.

**Is MOD-GRF (1-29) banned in sport?**

Yes. MOD-GRF (1-29) is prohibited in sport by the World Anti-Doping Agency under S2 (peptide hormones, growth factors, related substances and mimetics).

**How does MOD-GRF (1-29) work?**

MOD-GRF (1-29) is tetrasubstituted GRF(1-29) with amino acid replacements at positions 2, 8, 15, and 27 to resist enzymatic degradation. It binds the GHRH receptor and activates adenylyl cyclase/cAMP signaling in pituitary somatotrophs, producing a physiological GH pulse.

**What is known about the safety of MOD-GRF (1-29)?**

Generally well-tolerated. Similar safety profile to sermorelin and CJC-1295 no DAC.

## Key facts

- **Evidence tier:** C (Animal data)
- **FDA:** not approved
- **WADA:** prohibited (S2)
- **Peptide:** yes
- **Routes studied:** Subcutaneous, Intramuscular

## Overview

A modified growth hormone releasing factor with four amino acid substitutions for improved stability and bioavailability. Functionally equivalent to CJC-1295 without DAC.

## Mechanism

MOD-GRF (1-29) is tetrasubstituted GRF(1-29) with amino acid replacements at positions 2, 8, 15, and 27 to resist enzymatic degradation. It binds the GHRH receptor and activates adenylyl cyclase/cAMP signaling in pituitary somatotrophs, producing a physiological GH pulse. Its short half-life preserves the natural pulsatile secretion pattern.

## Effects reported in research

_Reported outcomes, not promises; see the evidence tier._

- Amplified pulsatile GH release
- Improved sleep architecture
- Enhanced lipolysis
- Synergistic with GHRP co-administration

## Safety & unknowns

Generally well-tolerated. Similar safety profile to sermorelin and CJC-1295 no DAC. Common side effects: flushing, headache, injection site reactions. Preserves natural GH feedback. Not FDA-approved.

## Studies

- Teichman SL, et al. (2006). *Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults*. Journal of Clinical Endocrinology and Metabolism. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/16352683/
  Foundational study on the modified GRF platform showing sustained GH stimulation and IGF-1 elevation in human subjects.

## Status sources

- [PubMed: tetrasubstituted GRF(1-29)](https://pubmed.ncbi.nlm.nih.gov/?term=modified+GRF+1-29)
- [WADA 2026 Prohibited List](https://www.wada-ama.org/en/prohibited-list)

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Educational reference only — not medical advice. No dosing information is published. Tiers rate the strength of published evidence, not effectiveness or safety.