What Is CJC-1295 No DAC? Modified GRF (1-29) Research Guide

CJC-1295 No DAC is a name widely used in the research-material market for a short-acting modified growth-hormone-releasing-hormone (GHRH) analogue, commonly referred to as Modified GRF (1-29) or Mod GRF (1-29). The terminology requires care because the original peer-reviewed human studies of CJC-1295 describe a different, long-acting molecule containing a Drug Affinity Complex (DAC) designed to bind circulating albumin.

This distinction is central to scientifically accurate documentation. CJC-1295 No DAC should not inherit pharmacokinetic claims reported for the DAC-linked form simply because both names contain “CJC-1295”. This guide explains the GHRH(1-29) research background, the difference between DAC and No-DAC materials, receptor biology, analytical characterisation and the limits of the available evidence.

What Is Growth-Hormone-Releasing Hormone?

Growth-hormone-releasing hormone is a hypothalamic peptide involved in regulation of growth hormone secretion from pituitary somatotroph cells. The biologically active N-terminal region of human GHRH can be represented by shorter peptide fragments, including GHRH(1-29)-NH2, which has been studied extensively as a research analogue.

Human studies from the 1980s and 1990s established that GHRH(1-29)-NH2 can stimulate growth hormone release and that selected amino-acid substitutions can alter potency, metabolic clearance and peptide persistence. These studies form part of the scientific foundation for later modified GHRH analogues.

What Does “Modified GRF (1-29)” Mean?

The term GRF means growth-hormone-releasing factor, an older synonym for GHRH. “1-29” refers to the first 29 amino-acid positions of the GHRH sequence. In research-market nomenclature, Modified GRF (1-29) generally refers to a modified 29-residue GHRH analogue intended to retain GHRH-receptor agonist activity while improving stability relative to the native fragment.

Importantly, commercial naming is not perfectly standardised. A laboratory should therefore rely on the actual sequence, molecular identity and batch documentation supplied for a material rather than assuming that every vial labelled “CJC-1295 No DAC” is analytically identical.

CJC-1295 No DAC Versus CJC-1295 With DAC

The most important naming issue is the difference between No-DAC material and the long-acting CJC-1295 described in the original clinical literature.

In a randomized human study published by Teichman and colleagues, CJC-1295 was engineered as a long-acting GHRH analogue with an albumin-binding Drug Affinity Complex. The study reported a multi-day estimated half-life and prolonged elevations in measured GH and IGF-I. Those pharmacokinetic findings relate to the DAC-containing molecule.

By contrast, the material sold as CJC-1295 No DAC / Modified GRF (1-29) lacks that albumin-binding DAC modification. It should therefore be treated as a distinct research material. Multi-day half-life figures from DAC-linked CJC-1295 should not be copied onto a No-DAC record.

GHRH-Receptor Signalling

The GHRH receptor is a class B G-protein-coupled receptor expressed prominently on pituitary somatotroph cells. Ligand binding promotes receptor conformational changes and intracellular signalling, including cyclic-AMP-associated pathways, which can contribute to regulated growth hormone release.

Research interpretation requires an understanding of the physiological system around the receptor. Growth hormone secretion is pulsatile and influenced by several signals, including endogenous GHRH, somatostatin, sleep, nutritional state and other neuroendocrine inputs. A GHRH analogue therefore acts within an already dynamic regulatory system rather than functioning as an isolated on/off switch.

What Earlier Human GHRH(1-29) Studies Show

Several peer-reviewed human studies evaluated GHRH(1-29)-NH2 and related analogues. In normal men, GHRH(1-29)-NH2 produced measurable GH responses and was reported to have molar potency comparable with longer GHRH fragments under the study conditions. Research also showed that selected substitutions, such as D-Ala at position 2, could reduce metabolic clearance and extend the short plasma disappearance time of the parent 1-29 fragment.

These studies are scientifically useful for understanding GHRH-fragment pharmacology, but they are not direct clinical validation of every modern product sold under the term Modified GRF (1-29). Exact molecular identity still needs to be established for the specific research material being tested.

Why the No-DAC Distinction Matters Analytically

Adding or removing an albumin-binding chemical group changes molecular mass, hydrophobicity, chromatographic behaviour and pharmacokinetics. As a result, a DAC-containing peptide and a No-DAC peptide cannot be treated as one analytical standard.

For laboratory work, the record should distinguish at minimum:

  • Material name: CJC-1295 No DAC / Modified GRF (1-29), where that naming is supported by the supplier documentation.
  • Sequence or structural specification: the exact molecular form represented by the batch.
  • DAC status: explicitly No DAC.
  • Nominal quantity: recorded separately from purity.
  • Batch identifier: linked to the applicable analytical report.

HPLC Purity and CJC-1295 No DAC

Reverse-phase high-performance liquid chromatography (RP-HPLC) is commonly used to assess peptide chromatographic purity. A principal peak can be integrated relative to other detected peaks under a defined method, providing a batch-specific purity result.

However, a high HPLC peak-area percentage does not independently establish sequence identity. A closely related peptide, truncated sequence or modified species may require additional analytical information to distinguish it from the intended material. Method details such as column chemistry, gradient, detector and integration settings also affect interpretation.

For more background, see Understanding HPLC Purity.

LC-MS and Molecular Identity

Liquid chromatography–mass spectrometry can complement HPLC by providing mass-to-charge information associated with chromatographically separated components. For a peptide whose commercial naming may be inconsistent, molecular-mass evidence is particularly useful.

A laboratory evaluating CJC-1295 No DAC should confirm that the analytical report corresponds to the expected molecular form and the exact production batch. Where sequence-level certainty is required, additional methods may be appropriate depending on the research objective.

Certificate of Analysis and Batch Traceability

A Certificate of Analysis is most useful when it can be linked directly to the vial being examined. The product name, strength or nominal quantity, batch identifier and analytical results should form one coherent record.

This is particularly important for CJC-related materials because “with DAC” and “No DAC” are chemically different. A COA for long-acting CJC-1295 with DAC does not verify a No-DAC vial, and a generic CJC-1295 report should not be assumed to identify which form was tested.

See the Certificate of Analysis Library, Certificate of Analysis Explained and Quality Assurance for the broader documentation framework used by Australian Peptide.

Evidence Limitations

The peer-reviewed literature is much stronger for native or modified GHRH fragments and for the original long-acting CJC-1295 with DAC than it is for every commercial material described as “CJC-1295 No DAC”. Consequently, scientific writing should clearly separate three evidence layers:

  • evidence about normal human GHRH physiology;
  • evidence about GHRH(1-29) and defined research analogues;
  • evidence about the exact batch and molecular form being supplied as CJC-1295 No DAC.

Collapsing those categories can produce inaccurate claims, particularly around half-life, potency and human evidence.

Frequently Asked Questions

Is CJC-1295 No DAC the same as CJC-1295 with DAC?

No. The DAC-linked molecule contains an albumin-binding modification designed to extend persistence. No-DAC material lacks that modification and should be documented separately.

Is CJC-1295 No DAC commonly called Modified GRF (1-29)?

Yes, that terminology is widely used in the research-material market. Because commercial nomenclature is inconsistent, laboratories should still confirm the actual molecular specification and batch documentation.

Can the 5.8–8.1 day half-life reported for CJC-1295 be applied to No-DAC material?

No. That estimate came from human research on long-acting CJC-1295 containing the DAC modification and should not be transferred to the No-DAC form.

What receptor pathway is relevant?

Modified GHRH analogues are studied as agonists of the GHRH receptor, part of the physiological system regulating pituitary growth hormone secretion.

Does an HPLC purity percentage prove the exact identity?

No. HPLC purity describes chromatographic composition under the stated method. Identity is a separate analytical question that may be supported by LC-MS and other techniques.

Selected Scientific References

Research Context

This article is provided for laboratory, analytical and scientific education. It does not provide dosing, administration, injection, therapeutic or personal-use instructions. Research materials should be identified and evaluated according to their actual molecular specification, batch documentation and applicable regulatory requirements.

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