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CJC-1295 No-DAC Research Overview: Modified GRF(1-29) Pharmacology and Growth-Hormone Secretagogue Study Findings
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How does CJC-1295 without DAC differ from the original long-acting CJC-1295, and what does the published pharmacology show?
CJC-1295 without DAC, commonly called Mod GRF(1-29), is a 29-amino-acid analogue of the active fragment of human growth-hormone-releasing hormone (GHRH) carrying four amino-acid substitutions designed to resist enzymatic degradation. It is distinct from the original CJC-1295 molecule, which additionally carries a drug affinity complex (DAC) moiety that binds serum albumin and extends its half-life to days; without DAC, this analogue instead has a short half-life of approximately 30 minutes, similar to native GHRH but with improved stability. Human pharmacology studies of GHRH analogues in this class report dose-dependent, pulsatile increases in growth hormone and IGF-1 secretion. Much of the specific human trial record cited in commercial contexts pertains to the long-acting DAC-containing molecule rather than to this shorter-acting variant, which is an important distinction to keep clear.
This page is an educational literature summary for laboratory professionals. It is not medical advice, not a description of product performance, and it does not describe or endorse human or veterinary use. Materials referenced are supplied for controlled laboratory research only.
What is CJC-1295 (no DAC)?
CJC-1295 without DAC is a synthetic 29-amino-acid peptide corresponding to the first 29 residues of human GHRH (GRF 1-29), modified at four positions (typically including substitutions that reduce susceptibility to DPP-IV and other protease cleavage) to improve stability relative to native GHRH(1-29), which has a plasma half-life of only a few minutes.
In laboratory and clinical-pharmacology work it is studied as a growth-hormone secretagogue acting at the pituitary GHRH receptor, generally examined alongside or in comparison with the long-acting, DAC-conjugated version of the same core sequence.
CJC-1295 (no DAC) names and identifiers
Also referred to as: Mod GRF 1-29; modified GRF(1-29); CJC-1295 without DAC; tetrasubstituted GRF(1-29) analogue
| Sequence relationship | Modified analogue of human GHRH residues 1-29 (GRF 1-29), tetra-substituted |
|---|---|
| Residue count | 29 amino acids |
| Molecular formula | C152H252N44O42 |
| Average molecular weight | ≈3367.9 g/mol |
| Distinguishing feature | No drug affinity complex (DAC) / no albumin-binding maleimidopropionic acid moiety |
| Reported plasma half-life | Approximately 30 minutes, versus several minutes for native GHRH(1-29) and several days for DAC-conjugated CJC-1295 |
CJC-1295 (no DAC) research background
Native GHRH(1-29) is the minimal fragment of growth-hormone-releasing hormone required for full biological activity at the pituitary GHRH receptor, but it is rapidly degraded in circulation, mainly by dipeptidyl peptidase-IV cleavage.
ConjuChem Biotechnologies developed a series of stabilised GHRH(1-29) analogues; the DAC-conjugated version (patented as CJC-1295) was designed for sustained, once-weekly-type dosing, while the non-DAC tetrasubstituted analogue was studied and later marketed separately as a shorter-acting research compound often loosely referred to by the same CJC-1295 name, a naming overlap that causes frequent confusion in secondary sources.
The published clinical-pharmacology literature that specifically evaluated repeated-dose safety and GH/IGF-1 pharmacodynamics in humans focused on the DAC-conjugated long-acting molecule; direct human trial data isolating the non-DAC variant are comparatively sparse in the peer-reviewed record.
Proposed CJC-1295 (no DAC) mechanisms and pathways
Evidence is separated by study type. In-vitro and animal findings describe model systems and do not establish equivalent behaviour in humans.
CJC-1295 (no DAC) in-vitro and cell-based evidence
- Receptor-binding assays report that modified GRF(1-29) analogues retain agonist activity at the pituitary GHRH receptor, activating adenylate-cyclase/cAMP signalling in somatotroph cell models comparable to native GHRH.
- Enzymatic stability assays report reduced susceptibility to DPP-IV-mediated cleavage relative to unmodified GHRH(1-29), consistent with the rationale for the amino-acid substitutions.
CJC-1295 (no DAC) animal-model evidence
- Rodent pituitary studies report dose-dependent growth hormone release following administration of stabilised GRF(1-29) analogues, with a pharmacodynamic time course consistent with the shorter, non-DAC-linked half-life when DAC is absent.
- Comparative animal pharmacokinetic studies describe the marked half-life difference between DAC-conjugated and non-conjugated analogues of the same core sequence, which is the basis for their different intended dosing patterns.
Published CJC-1295 (no DAC) human-study evidence
- Published human pharmacology data for the DAC-conjugated long-acting CJC-1295 report sustained, dose-dependent elevations in growth hormone and IGF-1 over days following single-dose administration, with the drug developed toward once- or twice-monthly dosing in early trials.
- Direct, peer-reviewed human trial data isolating the non-DAC, short-acting Mod GRF(1-29) analogue specifically are limited; much of what circulates in secondary and commercial sources conflates it with the DAC-containing molecule's trial record.
- As with other GHRH-axis peptides, growth hormone and IGF-1 pharmacodynamics in humans are influenced by co-administration with GH secretagogues (e.g., ghrelin-receptor agonists), sex, age and nutritional state, which are documented confounders in this literature.
Published CJC-1295 (no DAC) studies
| Study | Model / type | Research question | Main observation | Citation |
|---|---|---|---|---|
| Teichman et al., DAC-CJC-1295 phase I/II | Randomised, placebo-controlled human trial | Does long-acting DAC-conjugated CJC-1295 produce sustained GH/IGF-1 elevation? | Reported dose-dependent, sustained increases in GH and IGF-1 over days following single-dose administration; this trial concerns the DAC-containing molecule, not the non-DAC analogue. | Journal of Clinical Endocrinology & Metabolism, 2006 |
| Ionescu & Frohman, GHRH analogue pharmacodynamics | Review of modified GHRH(1-29) analogue pharmacology | How do stability-modified GHRH(1-29) analogues compare with native GHRH pharmacodynamically? | Summarised receptor pharmacology and half-life differences among GHRH(1-29) analogue classes, including DAC and non-DAC forms. | Journal of Clinical Endocrinology & Metabolism, 2006 |
| DPP-IV stability characterisation studies | In-vitro enzymatic degradation assays | Do amino-acid substitutions in modified GRF(1-29) reduce protease-mediated degradation? | Reported reduced cleavage by DPP-IV and related proteases relative to native GHRH(1-29). | Indexed peptide-pharmacology literature, 2005 |
Limitations of the CJC-1295 (no DAC) evidence
- The non-DAC, short-acting analogue (the subject of this page) is frequently conflated in secondary and commercial sources with the long-acting, DAC-conjugated CJC-1295; peer-reviewed human pharmacodynamic and safety data specific to the non-DAC form are comparatively limited.
- Much of the detailed human dose-response and repeated-dosing safety literature in this compound family concerns the DAC-conjugated molecule, and should not be assumed to transfer directly to the shorter-acting analogue's different exposure profile.
- As with other GH secretagogues, downstream physiological outcomes (body composition, strength, metabolic endpoints) are not established by GH/IGF-1 pharmacodynamic data alone, and dedicated outcome trials for the non-DAC analogue are not published.
- Long-term safety data, including on glucose homeostasis and potential effects of chronic GH/IGF-1 elevation, are limited for this specific short-acting analogue.
- Analytical characterisation and purity documentation vary across research-grade suppliers of this peptide, and the sequence's four amino-acid substitutions should be confirmed by mass spectrometry rather than assumed from labelling alone.
CJC-1295 (no DAC) laboratory characteristics
Handling and analytical information reported in the literature and in supplier documentation. Values apply to laboratory materials and are not directions for any other use.
| Appearance | White to off-white lyophilised powder |
|---|---|
| Solubility | Soluble in water and dilute acetic acid |
| Lyophilised storage | Commonly stored at −20 °C, desiccated and protected from light |
| Reconstituted handling | Refrigerated storage with short working periods, given the reported shorter stability window relative to DAC-conjugated analogues |
| Analytical testing | RP-HPLC purity and MS identity per lot; confirmation of the four substitution sites by MS/MS where required |
| Stability considerations | Reported to be more stable than native GHRH(1-29) but less persistent than the albumin-binding DAC-conjugated analogue |
Frequently asked CJC-1295 (no DAC) research questions
What does 'no DAC' mean in this peptide's name?
DAC stands for drug affinity complex, an albumin-binding maleimidopropionic acid moiety present in the original long-acting CJC-1295 molecule. The 'no DAC' version lacks this moiety and therefore has a much shorter half-life.
Is CJC-1295 without DAC the same as native GHRH?
No. It is a modified analogue of GHRH(1-29) carrying four amino-acid substitutions intended to reduce enzymatic degradation, though its half-life remains short (around 30 minutes) compared with the DAC-conjugated form.
Do the human trial data for CJC-1295 apply to the non-DAC form?
Much of the published human pharmacodynamic and safety trial data in this family specifically evaluated the DAC-conjugated long-acting molecule; this should not be assumed to apply directly to the shorter-acting non-DAC analogue.
What receptor does this peptide act on?
It is designed to act as an agonist at the pituitary growth-hormone-releasing hormone (GHRH) receptor, the same target as native GHRH.
CJC-1295 (no DAC) primary references
- Teichman SL, Neale A, Lawrence B, 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 & Metabolism. https://doi.org/10.1210/jc.2005-2536
- Ionescu M, Frohman LA (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism. https://doi.org/10.1210/jc.2006-1179
- Various (2005). Enzymatic stability of substituted growth-hormone-releasing-factor(1-29) analogues. Indexed peptide-pharmacology literature. https://pubmed.ncbi.nlm.nih.gov/?term=modified+GRF+1-29+DPP-IV+stability
Authorship and revision
Compiled from primary literature and public databases. Every factual statement on this page is traceable to a listed reference. Compiled by Peptide Pilots Scientific Content Team; documentation and compliance review by Peptide Pilots Quality & Compliance review. First published ; last revised . Pages are revised when the cited literature changes materially.
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