What Is CJC-1295 (No DAC)? Research Overview of the Modified GRF 1-29 Peptide

Overview

CJC-1295 without DAC — commonly referenced in the literature as Modified GRF 1-29 or mod-GRF (1-29), is a synthetic peptide analog of the first 29 amino acids of human growth hormone-releasing hormone (GHRH). It is studied as a tool compound for investigating the growth hormone (GH) secretory axis in laboratory and preclinical research settings. Unlike its counterpart CJC-1295 with DAC (Drug Affinity Complex), which is conjugated to extend systemic half-life, the No DAC variant is unmodified in that respect and is used in research contexts requiring a shorter-acting GHRH receptor agonist for mechanistic study.

Chemical Structure & Characteristics

Mod-GRF (1-29) is a 29-amino-acid peptide chain derived from the native GHRH(1-29) sequence, incorporating several amino acid substitutions designed to confer resistance to enzymatic degradation, particularly cleavage by dipeptidyl peptidase-4 (DPP-4) and other proteases that rapidly inactivate native GHRH. These substitutions improve the peptide's in vitro stability profile relative to unmodified GHRH fragments, making it a more tractable subject for laboratory assays. The compound has an approximate molecular weight in the range of 3,647 g/mol and is typically supplied as a lyophilized powder for research applications.

Mechanism of Action

As a GHRH receptor agonist, mod-GRF (1-29) is studied for its ability to bind GHRH receptors located on somatotroph cells of the anterior pituitary in in-vitro and animal-model systems. Receptor binding activates adenylate cyclase signaling and increases intracellular cyclic AMP (cAMP), a pathway associated with stimulation of endogenous growth hormone synthesis and secretion. Because the peptide retains the core structural motif of native GHRH, it is used experimentally to probe GHRH receptor pharmacology, downstream signal transduction cascades, and pulsatile GH release patterns in model systems, without the extended receptor occupancy associated with DAC-conjugated analogs.

Research Considerations

For laboratory use, mod-GRF (1-29) is generally handled as a lyophilized peptide requiring storage at -20°C or colder prior to reconstitution for assay purposes, and refrigerated, protected from light, and used promptly once in solution, consistent with standard peptide-stability practices. Researchers commonly evaluate incoming material against a Certificate of Analysis (COA) confirming identity via mass spectrometry and purity via HPLC, typically reporting purity at or above 98% for research-grade material. Repeated freeze-thaw cycles and prolonged exposure to heat, light, or ambient humidity are known to accelerate peptide degradation and are generally avoided in laboratory protocols to preserve sample integrity for experimental reproducibility.

Preclinical Research Summary

Published preclinical literature on GHRH(1-29) analogs, including modified variants such as mod-GRF (1-29), has examined their effects on GH secretion dynamics in rodent and other animal models. These studies have investigated dose-response relationships between GHRH receptor agonism and pulsatile GH release, downstream effects on insulin-like growth factor 1 (IGF-1) signaling pathways, and the pharmacokinetic distinctions between short-acting GHRH fragments and their long-acting, DAC-conjugated counterparts. Such research has contributed to the broader scientific understanding of hypothalamic-pituitary GH axis regulation and receptor-level pharmacology, informing further investigation into peptide-based GHRH receptor agonists as research tools.

Research Use Only

CJC-1295 (No DAC) / Modified GRF 1-29 as offered by Apex Molecular Labs is intended strictly for laboratory and preclinical research purposes. It is not a drug, dietary supplement, or medical product, and is not intended for human or veterinary use, diagnostic use, or administration of any kind. All material is sold exclusively to qualified researchers and institutions for in-vitro and animal-model study in controlled laboratory environments, in accordance with applicable research-use regulations.