CJC-1295 (No DAC): A Research Overview

CJC-1295 without DAC — also referred to in the literature as Modified GRF (1-29) or Mod GRF 1-29 — is a synthetic analog of the first 29 amino acids of growth hormone-releasing hormone (GHRH), the segment identified in the literature as carrying GHRH's biological activity. It has been used as a tool compound in preclinical studies exploring how the pituitary somatotroph axis is regulated. This overview summarizes what published research on GHRH analogs of this class has examined, in cell and animal models, and is provided strictly for educational and laboratory-reference purposes. It is not medical guidance, and nothing here describes human treatment, dosing, administration, or outcomes.^[1]

What CJC-1295 (No DAC) is

Native GHRH is rapidly degraded in plasma, in large part by the enzyme dipeptidyl peptidase-IV (DPP-IV), which studies describe as limiting its persistence in experimental systems. CJC-1295 without DAC was designed as a GRF(1-29) sequence carrying four amino acid substitutions reported to be intended to improve resistance to enzymatic cleavage while preserving the receptor-binding region.^[2] Substitutions described in this analog class in the literature include:

• A D-Ala substitution at position 2, studied for its role in slowing DPP-IV cleavage of the N-terminal peptide bond;
• Substitutions at positions 8, 15, and 27, examined in the context of oxidative and enzymatic stability.

The key distinction from the "DAC" version is the absence of the Drug Affinity Complex (DAC) — a maleimide linker that, in the DAC variant, is described as binding covalently to circulating albumin and thereby extending persistence in research models. Without that linker, CJC-1295 (No DAC) has been characterized in the literature as a comparatively short-acting analog, with a much shorter modeled half-life than the albumin-binding DAC form.^[3] This "No DAC" property is described as the central reason the compound has been of interest to researchers studying pulsatile, rather than sustained, receptor activation.

Mechanism explored in the literature

GHRH and its analogs are described as acting at the GHRH receptor (GHRH-R), a Gs-protein-coupled receptor expressed on anterior-pituitary somatotroph cells. In preclinical models, receptor engagement has been associated in the literature with activation of adenylyl cyclase, elevation of intracellular cyclic AMP (cAMP), and downstream signaling that studies have linked to growth-hormone (GH) gene expression and secretion.^[2] Research on Modified GRF (1-29) has examined whether the introduced substitutions preserve this receptor-binding pharmacophore while altering the compound's metabolic stability profile.

Because CJC-1295 (No DAC) is studied as a short-acting analog, investigators have used it in models designed to probe time-limited receptor activation and the pulsatile character of GH release, as opposed to the continuous receptor occupancy associated with longer-acting constructs.^[4]

Areas of preclinical investigation

Published and preprint research involving GHRH analogs of this class has explored, in cell culture and animal models, questions such as:

• Pituitary signaling: how GHRH-R engagement relates to cAMP-mediated somatotroph activity in laboratory preparations;^[2]
• Pulsatile GH dynamics: how short-acting versus long-acting GHRH analogs differ in the temporal pattern of GH release observed in animal models;^[4]
• Combination pharmacology: how a GHRH analog behaves alongside growth hormone-releasing peptides (GHRPs) such as ipamorelin or GHRP-2, which are reported to act through a separate (ghrelin/GHS) receptor pathway — an interaction studied in preclinical work on the two arms of GH regulation;^[5]
• The somatotropic axis: how GHRH-analog exposure relates to downstream markers such as insulin-like growth factor 1 (IGF-1) in research models.^[1]

These are descriptions of what researchers have investigated. They are not statements that any effect is established, beneficial, or applicable to humans.

What the research does not establish

It is important to be clear about the limits of the evidence base:

• The available literature on CJC-1295 (No DAC) / Modified GRF (1-29) is largely preclinical — cell-based and animal-model work — and much of what circulates about this specific analog comes from non-clinical sources rather than well-controlled human clinical trials.
• Well-controlled human clinical trials of this compound are not part of the established record, and its safety and effects in humans are not established here.
• CJC-1295 (No DAC) as sold is not FDA-approved, is not a dietary supplement, and is not a medicine. It should not be understood as an approved drug product.
• It is offered for laboratory and research use only, and is not intended for human or veterinary use, diagnosis, or the prevention or treatment of any condition.

Researchers evaluating any peptide should also consider material identity and purity. Meridian ships a lot-specific Certificate of Analysis and tests to 99%+ purity by HPLC with mass-spectrometry identity verification, so that documented material characteristics are available for laboratory records.

Frequently asked questions

Is CJC-1295 (No DAC) the same as "Modified GRF (1-29)"?

In the research literature the terms are used for the same GHRH(1-29) analog carrying the stability substitutions but lacking the albumin-binding DAC linker. "No DAC" distinguishes it from the longer-acting DAC construct.^[3]

How does the "No DAC" form differ from the DAC form in research terms?

The DAC form includes a linker described as binding albumin to prolong persistence in research models, whereas the No DAC form is studied as a comparatively short-acting analog associated with pulsatile rather than sustained receptor activation.^[3] Neither description implies any human use.

Is this compound approved or safe for people?

No. As discussed above, it is not FDA-approved, not a supplement, and is sold strictly for laboratory and research use only. Its safety and effects in humans are not established.

Why is it often studied together with a GHRP?

GHRH analogs and GHRPs are described as engaging two distinct receptor systems in the GH axis, so combination studies are used in preclinical work to examine how the two pathways relate under laboratory conditions.^[5]