CJC-1295 No DAC is a synthetic peptide analog of growth hormone-releasing hormone (GHRH), the endogenous hypothalamic peptide responsible for stimulating growth hormone secretion from the anterior pituitary gland. The compound is a modified version of the first 29 amino acids of native GHRH, designated GHRH(1-29), with several amino acid substitutions incorporated to improve metabolic stability relative to the endogenous peptide. The designation “No DAC” distinguishes this compound from a related analog that incorporates a drug affinity complex (DAC) technology designed to extend circulating half-life through albumin binding. Without the DAC modification, CJC-1295 No DAC retains a pharmacokinetic profile more closely resembling native GHRH(1-29), making it a research tool of interest for investigating pulsatile growth hormone secretion and somatotropic axis biology in preclinical settings. The compound has been examined in published research across rodent and human study contexts, with its receptor binding characteristics and endocrine effects forming the primary focus of the scientific literature. CJC-1295 No DAC is available for research purposes and is not intended for human or veterinary use.

Chemical and Structural Profile

CJC-1295 No DAC, also referred to in the scientific literature as modified GRF(1-29) or Mod GRF(1-29), is a 29-amino acid linear peptide with a molecular formula of C152H252N44O42 and a molecular weight of approximately 3,367.9 daltons. The compound incorporates four amino acid substitutions relative to native GHRH(1-29): substitution of alanine for tyrosine at position two, substitution of alanine for aspartate at position eight, substitution of glutamine for asparagine at position 15, and substitution of alanine for leucine at position 27. These substitutions were introduced to improve resistance to enzymatic cleavage by dipeptidyl peptidase IV (DPP-IV) at the N-terminus and by endopeptidases at internal cleavage sites that limit the circulating half-life of native GHRH(1-29) in vivo.

As a linear peptide without cyclic structural elements or disulfide bonds, CJC-1295 No DAC presents a relatively straightforward structural profile from a synthetic chemistry perspective, though its length of 29 amino acids places it among the larger research peptides commonly studied in somatotropic biology. The compound does not incorporate the reactive maleimide group that is present in the DAC-bearing CJC-1295 analog, which simplifies its storage and handling characteristics and eliminates concerns about non-specific albumin conjugation that can complicate pharmacokinetic analysis of the DAC-bearing version in research settings.

Published pharmacokinetic research characterizing GHRH analogs in rodent and human contexts has reported half-life values for GHRH(1-29) analogs in the range of 20 to 30 minutes in circulation, substantially longer than the approximately two minute half-life reported for native GHRH(1-29) under similar conditions. Research-grade CJC-1295 No DAC is supplied as a lyophilized powder, which provides greater structural stability during storage than aqueous formulations and is the standard supply format for research peptides of this class. High-performance liquid chromatography (HPLC) is the standard analytical method for purity assessment, with mass spectrometry used to confirm the molecular identity and verify the amino acid substitution pattern characteristic of the compound.

Mechanism of Action

The mechanistic basis of CJC-1295 No DAC activity, as characterized in published preclinical and clinical research, centers on its agonist activity at the GHRH receptor (GHRHR), a G protein-coupled receptor expressed predominantly on somatotroph cells of the anterior pituitary gland. Binding of CJC-1295 No DAC to GHRHR initiates intracellular signaling through the stimulatory G protein (Gs) pathway, leading to activation of adenylyl cyclase and subsequent elevation of cyclic adenosine monophosphate (cAMP) within pituitary somatotroph cells. The rise in intracellular cAMP activates protein kinase A (PKA), which phosphorylates downstream effector proteins involved in the regulation of growth hormone gene expression and secretory vesicle exocytosis. This signaling cascade has been characterized in cell culture systems using pituitary cell preparations and represents the canonical mechanism through which GHRH and its analogs stimulate growth hormone release in preclinical research models.

Animal model studies have examined the downstream endocrine effects of GHRH(1-29) analogs, reporting dose-dependent stimulation of growth hormone secretion from the anterior pituitary following systemic administration in rodent models. The amino acid substitutions incorporated into CJC-1295 No DAC confer resistance to DPP-IV cleavage at the N-terminus, which published pharmacokinetic research suggests extends the window of GHRHR engagement relative to native GHRH(1-29) under equivalent experimental conditions. This extended receptor engagement has been proposed in the literature as the basis for the more sustained growth hormone secretory responses observed with GHRH analogs compared to the native peptide in preclinical models.

Published research has also examined the downstream effects of GHRHR activation on insulin-like growth factor 1 (IGF-1) production in animal model systems. Rodent studies have reported elevations in circulating IGF-1 following administration of GHRH analogs, reflecting the established relationship between growth hormone secretion and hepatic IGF-1 production in the somatotropic axis. The IGF-1 response has been used as a downstream biomarker of somatotropic axis engagement in preclinical research examining CJC-1295 No DAC and related analogs, providing a measurable endpoint for evaluating the biological activity of these compounds in experimental settings. The precise magnitude and duration of IGF-1 responses reported in published studies vary across experimental conditions, species, and administration parameters, reflecting the complexity of somatotropic axis regulation in different research model systems.

Key Research Areas

Somatotropic Axis and Growth Hormone Secretion Research

The primary and most extensively published research area for CJC-1295 No DAC and related GHRH analogs involves the characterization of growth hormone secretory responses in preclinical and early clinical research contexts. Teichman and colleagues published a foundational study in the Journal of Clinical Endocrinology and Metabolism (2006) examining CJC-1295 with DAC in human subjects, providing pharmacokinetic and pharmacodynamic data that established the research framework subsequently applied to the No DAC analog. Rodent model studies have examined GHRH(1-29) analogs including the modified GRF(1-29) sequence in the context of pulsatile growth hormone secretion, with researchers measuring growth hormone pulse amplitude and frequency parameters under various experimental conditions. The somatotropic axis literature for this compound class is the most substantive and independently replicated portion of the published record and forms the primary scientific rationale for its continued use as a research tool in endocrine biology investigations.

IGF-1 Axis and Anabolic Signaling Research

Published animal model research has examined the effects of GHRH analog administration on IGF-1 production and downstream anabolic signaling pathways in rodent experimental systems. Studies have reported elevations in circulating IGF-1 concentrations in rodent models following administration of GHRH analogs, with researchers examining hepatic IGF-1 gene expression and circulating IGF-1 protein levels as primary outcome measures in these experiments. The relationship between GHRHR activation, growth hormone secretion, and IGF-1 production represents a well-characterized axis in endocrine biology, and CJC-1295 No DAC has been examined as a research tool for probing this axis in preclinical model systems. The anabolic signaling literature in this context remains predominantly confined to animal model observations, with the mechanistic details of downstream IGF-1 receptor signaling examined in parallel cell culture research examining IGF-1 receptor pathway activation in various cell types.

Hypothalamic-Pituitary Axis Regulation Research

A published body of preclinical research has examined GHRH analogs in the context of hypothalamic-pituitary axis regulation, with studies investigating the interplay between exogenous GHRHR agonism and endogenous regulatory mechanisms including somatostatin tone. The hypothalamic-pituitary-somatotropic axis is subject to complex regulatory feedback involving somatostatin, a hypothalamic peptide that inhibits growth hormone secretion and counterbalances GHRH activity. Published rodent model research has examined how GHRH analog administration interacts with endogenous somatostatin release and how the timing of GHRHR agonism relative to somatostatin secretory patterns influences the growth hormone secretory profile observed in experimental animals. This research area reflects broader scientific interest in understanding the physiological regulation of the somatotropic axis and the utility of synthetic GHRH analogs as research tools for probing these regulatory mechanisms in controlled experimental settings.

Metabolic and Body Composition Research

Animal model studies have examined GHRH analogs including modified GRF(1-29) in metabolic research contexts, with published research investigating parameters related to body composition and metabolic function in rodent experimental models. Ionescu and Frohman published a review in the Journal of Clinical Endocrinology and Metabolism (2006) examining the clinical research landscape for GHRH analogs, providing context for interpreting the preclinical metabolic research conducted with compounds in this class. Rodent studies have examined body composition parameters including lean mass and adipose tissue distribution in animals receiving GHRH analog treatment under various experimental conditions, with researchers measuring these parameters alongside circulating growth hormone and IGF-1 as mechanistic markers of somatotropic axis engagement. The metabolic research literature for CJC-1295 No DAC specifically is less developed than the endocrine secretion literature, and the findings reported in animal models require further investigation before their implications can be fully characterized.

Research Considerations for Laboratory Use

Research-grade CJC-1295 No DAC is supplied in lyophilized form and requires appropriate storage conditions to maintain compound integrity for experimental use. Long-term storage at -20 degrees Celsius or below is recommended, with desiccation to protect against moisture-induced degradation during storage. As a 29-amino acid peptide, CJC-1295 No DAC is more susceptible to aggregation and physical instability than smaller peptides under certain conditions, and researchers should take care to avoid mechanical stress such as vigorous vortexing during reconstitution, which can promote peptide aggregation and compromise compound integrity.

For laboratory reconstitution, sterile water or bacteriostatic water is the standard solvent used in research settings for GHRH analog peptides, with the reconstitution volume determined entirely by the concentration requirements of the specific experimental protocol. Reconstituted solutions should be prepared in quantities appropriate for planned experimental use and stored at 4 degrees Celsius for short-term use, with longer-term storage maintained in single-use aliquots at -20 degrees Celsius to minimize freeze-thaw cycling. The absence of the DAC maleimide group in CJC-1295 No DAC eliminates concerns about non-specific protein conjugation during storage, simplifying the handling profile relative to the DAC-bearing analog.

Purity specification is particularly important for GHRH analog research given the sensitivity of pituitary cell-based assay systems to impurities that may have biological activity at the receptors involved in somatotropic regulation. Research-grade CJC-1295 No DAC should be accompanied by a lot-specific certificate of analysis (COA) from an independent third-party testing laboratory, with purity verified by HPLC to a specification of 99% or greater. Mass spectrometry confirmation is essential to verify the amino acid substitution pattern that distinguishes CJC-1295 No DAC from native GHRH(1-29) and from the DAC-bearing CJC-1295 analog, as these compounds have distinct research profiles and cannot be used interchangeably in experimental designs that depend on specific pharmacokinetic characteristics. Researchers should review lot-specific COA documentation from independent laboratories prior to procurement to ensure the analytical confidence required for reproducible experimental results.

Published Literature and References

The published literature directly examining CJC-1295 No DAC is more limited in volume than the literature available for some other research peptides, reflecting the compound’s more recent emergence as a distinct research tool relative to its parent compound GHRH(1-29) and the DAC-bearing CJC-1295 analog. The most substantive published research on the compound class has examined GHRH analogs broadly, with the specific modified GRF(1-29) sequence that defines CJC-1295 No DAC appearing in preclinical literature and pharmacokinetic characterization studies. The somatotropic axis and growth hormone secretion research domain is the most thoroughly documented, with metabolic and body composition research areas representing smaller portions of the available literature. All cited studies were conducted in preclinical animal model or early clinical research settings, and further independent research is ongoing. This article is a research overview compiled from published scientific sources and does not constitute medical advice.

References:

Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA, 2006. Prolonged stimulation of growth hormone and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of growth hormone-releasing hormone, in healthy adults. Journal of Clinical Endocrinology and Metabolism. PMID: 16352683

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 and Metabolism. PMID: 16684825

Alba M, Fintini D, Sagazio A, Lawrence B, Castaigne JP, Frohman LA, Salvatori R, 2006. Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. American Journal of Physiology – Endocrinology and Metabolism. PMID: 16868229

Jetté L, Leger R, Thibaudeau K, Benquet C, Robitaille M, Pellerin I, Paradis V, van Wyk P, Pham K, Bridon DP, 2005. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats. Endocrinology. PMID: 15564323

Frohman LA, Jansson JO, 1986. Growth hormone-releasing hormone. Endocrine Reviews. PMID: 2420468

Bowers CY, 1998. Growth hormone-releasing peptide (GHRP). Cellular and Molecular Life Sciences. PMID: 9529905

Svensson J, Lall S, Dickson SL, Bengtsson BA, Romer J, Ahnfelt-Ronne I, Ohlsson C, Jansson JO, 2000. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats. Journal of Endocrinology. PMID: 10657022

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This article is intended for informational and research reference purposes only. CJC-1295 No DAC is sold strictly for laboratory and research use. It is not intended for human or veterinary consumption, and this content does not constitute medical advice, treatment recommendations, or clinical guidance. All research applications referenced in this article are based on preclinical literature. Researchers should consult applicable regulations and institutional guidelines before use.