Research Use Only. The information on this page summarizes published peptide research for laboratory and educational reference. The compounds discussed are intended exclusively for in vitro and non-clinical research. Nothing on this page constitutes medical advice or describes human use, diagnosis, treatment, or therapeutic application.
Overview
What is CJC-1295? It is a synthetic 29-amino-acid analog of growth hormone releasing hormone (GHRH), developed by the Canadian biotechnology company ConjuChem and described in the published research literature as a long-acting GHRH receptor agonist. The compound has become one of the most extensively studied research peptides in the growth hormone axis category and the reference compound for parallel-arm research with ghrelin receptor agonists like Ipamorelin.
The name CJC-1295 encompasses two related but pharmacokinetically distinct compounds in research peptide commerce. CJC-1295 with DAC (Drug Affinity Complex) is the long-acting version, characterized by covalent attachment to serum albumin and a published half-life of approximately six to eight days. CJC-1295 without DAC, sometimes labeled Modified GRF (1-29) or Mod GRF 1-29, is the short-acting analog with a half-life measured in minutes to hours. The distinction is methodologically critical because the two compounds produce substantially different time courses of growth hormone release and require different experimental designs. This article uses CJC-1295 to refer to the DAC-modified version unless specifically noted, since the DAC variant is what most research peptide commerce supplies under the unqualified CJC-1295 label.
The biological activity profile that defines CJC-1295 in the published literature depends on the specific 29-amino-acid sequence, on the four substitution sites that confer enzymatic stability, and on the maleimidopropionic acid linker that mediates albumin binding in the DAC version. Synthesis errors, sequence variants, missing or improperly attached DAC linkers, and other defects can substantially alter the half-life and the time-integrated GHRH receptor stimulation in ways that phenotypic readouts often miss. The line between research-grade peptide commerce and gray-market pharmaceutical distribution runs through this verification step, since a CJC-1295 preparation whose DAC linker integrity is not analytically confirmed cannot be assumed to behave like the long-acting compound characterized across the published GH-axis pharmacology literature.
This article covers what CJC-1295 is at the structural and biochemical level, the relationship between CJC-1295 with DAC and the non-DAC analog, the GHRH receptor pharmacology and downstream signaling, the model systems most commonly used for CJC-1295 work, and the methodology considerations that govern rigorous in vitro and pre-clinical research with the compound. It sits within the GENEVIUM Research Hub coverage of growth hormone axis peptide research, in the Healing & Sleep pillar. The broader category context is treated in the Recovery Peptide Research overview, and the dedicated parallel comparison to the ghrelin receptor agonist Ipamorelin is covered in CJC-1295 vs Ipamorelin Research Comparison. For the broader research-use-only framework that governs all GENEVIUM peptides, see What Research Use Only Means.
What Is CJC-1295 at the Molecular Level
CJC-1295 is a synthetic analog of growth hormone releasing hormone, specifically a modified version of the biologically active 1-29 N-terminal fragment of human GHRH. The native GHRH sequence is 44 amino acids long, but functional GH-releasing activity is retained in the first 29 residues, which became the starting point for development of synthetic GHRH analogs in the 1980s and 1990s. CJC-1295 was developed by ConjuChem, a Canadian biotechnology company that pioneered the Drug Affinity Complex technology underlying the long-acting version of the compound.
Sequence and Substitutions
The base sequence of CJC-1295 corresponds to GHRH residues 1 through 29 with four substitution sites engineered to confer enzymatic stability against the proteases that rapidly degrade native GHRH in vivo. The substitutions are at positions 2 (D-alanine for stability against dipeptidyl peptidase IV), 8, 15, and 27. The result is a 29-amino-acid peptide that retains the GHRH receptor binding profile of the native hormone but is substantially more stable against systemic degradation than the unmodified GHRH 1-29 fragment.
The substitution at position 2, D-alanine in place of L-alanine, is particularly important. Dipeptidyl peptidase IV cleaves native GHRH at the N-terminus within minutes, eliminating biological activity. The D-alanine substitution at position 2 blocks this cleavage and is the single most important stability modification in CJC-1295.
The Drug Affinity Complex (DAC) Modification
CJC-1295 with DAC adds a maleimidopropionic acid linker at the C-terminus of the 29-amino-acid sequence. This linker contains a reactive maleimide group that forms a covalent thioether bond with the free thiol of cysteine-34 on serum albumin. The result is a peptide-albumin conjugate that circulates with a half-life approaching that of serum albumin itself, approximately nineteen to twenty days, although the practical functional half-life observed in published research is shorter at roughly six to eight days.
The DAC mechanism is what distinguishes the long-acting version from the non-DAC analog. CJC-1295 without DAC has the same 29-amino-acid sequence with the same four stability substitutions, but lacks the maleimidopropionic acid linker. Without the albumin binding mechanism, the peptide circulates freely and is cleared with a half-life of roughly thirty minutes to a few hours depending on the model system. The two compounds are biochemically related but pharmacokinetically very different, and the research literature treats them as distinct compounds for experimental purposes.
Synthesis and Stability
CJC-1295 is produced by solid-phase peptide synthesis using standard fluorenylmethoxycarbonyl (Fmoc) chemistry, followed by attachment of the maleimidopropionic acid linker at the C-terminus for the DAC version. The peptide is purified by reverse-phase HPLC to research-grade purity standards (typically minimum 99% by reverse-phase HPLC) and characterized by mass spectrometry to confirm sequence identity and DAC linker integrity. The synthesis route is established and well-documented, and CJC-1295 has become widely available as a research peptide as a result.
Solubility in aqueous research buffers is good. Standard reconstitution uses bacteriostatic water, and reconstituted CJC-1295 retains stability at refrigerator temperatures over the time course of typical research experiments. Long-term storage of lyophilized CJC-1295 is at minus 20 degrees Celsius or lower in dry conditions. Repeated freeze-thaw cycles should be avoided.
Proposed Mechanisms of Action
The mechanistic identity of CJC-1295 is rooted in GHRH receptor pharmacology. Unlike the multi-pathway tissue-repair peptides where the molecular target remains incompletely characterized, CJC-1295 has a clearly identified primary receptor target, well-characterized downstream signaling, and a quantitative relationship between receptor activation and growth hormone release. The mechanism is one of the most rigorously documented in the recovery peptide category.
GHRH Receptor Binding
CJC-1295 binds the growth hormone releasing hormone receptor (GHRHR), a class B G-protein-coupled receptor expressed primarily on somatotroph cells of the anterior pituitary gland. The receptor is the physiological target of native GHRH and mediates the hypothalamic control of growth hormone release. Substitutions and structural modifications in CJC-1295 preserve high-affinity binding to the GHRHR, which is the foundation of all downstream effects of the compound.
The binding kinetics of CJC-1295 with DAC differ from native GHRH and from the non-DAC analog in one important respect. Because the DAC version circulates bound to albumin, the effective free concentration available for receptor binding at any given moment is lower than the total circulating concentration. The molecule is delivered continuously to the receptor over the multi-day functional half-life rather than as a single high-concentration bolus. This time-integrated stimulation profile is the basis for the prolonged GH release effects observed in published research.
cAMP Signaling and Growth Hormone Release
GHRH receptor activation triggers a Gαs-coupled signaling cascade producing cyclic AMP, which activates protein kinase A, which phosphorylates the transcription factor CREB. CREB phosphorylation drives transcription of the growth hormone gene and contributes to the synthesis of new GH alongside the release of pre-stored GH from somatotroph secretory granules. The cAMP pathway is the canonical GHRH signaling mechanism and operates identically for native GHRH and for CJC-1295.
The functional consequence is increased growth hormone release from the pituitary into systemic circulation. This downstream GH then acts on hepatic GH receptors to stimulate IGF-1 production, on adipose tissue to promote lipolysis, and on multiple peripheral tissues for the broader anabolic and metabolic effects of GH-IGF-1 axis activation.
Preserved Pulsatility
One of the more counterintuitive findings in the published CJC-1295 literature concerns growth hormone pulsatility. Continuous GHRH receptor stimulation might be expected to produce sustained, non-pulsatile GH release, which would be undesirable because continuous GH exposure causes receptor downregulation and loss of biological effect. Published research using CJC-1295 has documented that the pulsatile pattern of GH release is preserved despite continuous receptor stimulation, mediated by the counter-regulatory action of hypothalamic somatostatin.
The preserved pulsatility means that CJC-1295 increases the amplitude of natural GH pulses rather than overriding them with a continuous release pattern. From a research methodology perspective, this is what makes CJC-1295 valuable as a tool compound for GH-axis research: the compound increases integrated GH exposure without disrupting the pulsatile signaling that downstream tissues are biologically tuned to receive.
Areas of Active CJC-1295 Research
Several distinct research areas use CJC-1295 as a primary investigational compound. Each is characterized by its own model systems and endpoints, and researchers new to CJC-1295 work benefit from understanding which areas have the strongest published evidence base.
Growth Hormone Pharmacokinetic Research
The foundational CJC-1295 research literature focuses on the pharmacokinetic and pharmacodynamic profile of the compound: how plasma concentrations rise and fall over time, how those concentrations relate to GH release, and how the pulsatile pattern of GH secretion responds to sustained receptor activation. Published clinical pharmacology studies in healthy adults established the multi-day functional half-life of the DAC version and characterized the integrated GH and IGF-1 response over the dosing interval.
GH-IGF-1 Axis Research
Beyond the immediate pharmacokinetic profile, CJC-1295 has been used as a tool compound for broader GH-IGF-1 axis research. The downstream effects of sustained GH receptor stimulation on hepatic IGF-1 production, on IGF binding protein expression, and on the systemic anabolic and metabolic markers of GH-axis activation are studied across both clinical research and pre-clinical animal models. The compound serves as a reproducible, long-acting stimulus that allows examination of GH-axis dynamics on a different time scale than is possible with short-acting GHRH analogs.
Parallel-Arm Research with Ghrelin Receptor Agonists
CJC-1295 is most commonly studied alongside Ipamorelin, a synthetic pentapeptide ghrelin receptor agonist, in parallel-arm research designs investigating combined or comparative effects of the two growth hormone secretagogue pathways. The mechanistic rationale is that CJC-1295 engages the GHRHR pathway while Ipamorelin engages the GHS-R1a (ghrelin receptor) pathway, and the two converge on growth hormone release through distinct upstream signaling that can be quantitatively dissected with parallel-arm experimental design.
Sleep Architecture and Growth Hormone Coupling
A smaller but distinct line of research examines the relationship between CJC-1295 administration and the sleep-coupled pattern of growth hormone release. Endogenous GH release is concentrated in the slow-wave sleep phases of the early night, and the interaction between sustained CJC-1295-mediated GHRHR stimulation and this physiologically pulsatile sleep-coupled release has been studied in the context of broader sleep-and-restoration research.
Research Methodology and Quality Standards
CJC-1295 research is sensitive to compound purity and identity confirmation, with one verification consideration that does not apply to most other research peptides. The DAC linker integrity is an additional analytical checkpoint beyond the standard 29-amino-acid sequence verification, and the theoretical molecular weight of CJC-1295 with DAC differs from CJC-1295 without DAC by the mass of the maleimidopropionic acid linker. Mass spectrometry confirmation must match the documented version on the Certificate of Analysis, and material whose mass profile is intermediate between the two versions has either incomplete DAC attachment or contamination with the non-DAC analog.
Published research consistently uses minimum 99% purity by reverse-phase HPLC, with mass spectrometric identity confirmation matching the theoretical molecular weight for the specific version (DAC or non-DAC), as the standard threshold for growth hormone axis peptide work. The methodology distinction between the two versions is not optional. Research designs intended to study the long-acting compound cannot accept material whose DAC integrity is unverified, and research designs intended to study the short-acting Modified GRF 1-29 cannot accept material contaminated with the DAC version. Suppliers shipping CJC-1295 under loose labeling without documenting which version is in the vial are not operating to research-grade standards regardless of the headline purity figure.
Reconstitution methodology should be standardized within and across studies. Bacteriostatic water is the most common reconstitution medium. The final concentration and the time elapsed between reconstitution and use should be reported in published research, since stability over hours to days at refrigerator temperature is good but not unlimited. Repeated freeze-thaw cycles should be avoided. For a detailed treatment of lyophilization, storage temperatures, and quality indicators researchers use to assess lyophilized peptide material before reconstitution, see Lyophilized Peptides: Methodology and Stability. For the analytical chemistry behind HPLC peptide verification, including the chromatogram interpretation skills required to verify DAC linker integrity by retention time, see HPLC Peptide Verification.
Standard model systems for CJC-1295 research include in vivo rodent endocrinology preparations for pharmacokinetic and pharmacodynamic characterization, in vitro pituitary cell preparations for direct GHRHR signaling readouts, and clinical pharmacology designs for the human pharmacokinetic literature. GH release into the systemic circulation is the primary readout for most CJC-1295 research, with IGF-1 measurement as the secondary downstream marker. Cell-based assays should specify the pituitary cell preparation used and the GH release assay methodology, since baseline pulsatility characteristics vary significantly across preparations.
GENEVIUM publishes a batch-specific Certificate of Analysis for every research peptide and makes them retrievable by batch number on the COA Lookup Page.
The growth hormone axis pharmacology that distinguishes CJC-1295 in the published literature only holds for material whose 29-amino-acid sequence integrity, four stability substitutions, and DAC linker (for the long-acting version) are analytically confirmed on each batch. A supplier that documents sequence purity, mass-spectrometric identity, and DAC linker integrity on a batch-specific Certificate of Analysis retrievable by lot number is operating on the research-grade side of the line between legitimate research peptide commerce and gray-market pharmaceutical distribution. A supplier that ships CJC-1295 under loose nomenclature without specifying the DAC or non-DAC version, or that aggregates purity across batches without lot-level documentation, is not, regardless of the headline purity figure displayed at point of sale.
Frequently Asked Questions
What does CJC-1295 stand for?
CJC stands for ConjuChem, the Canadian biotechnology company that developed the compound. The 1295 designation is an internal compound numbering convention from ConjuChem product development records and does not encode chemical or sequence information. CJC-1295 was first characterized in the published research literature in the mid-2000s, with the foundational human pharmacokinetic study published by Teichman and colleagues in 2006.
What is the difference between CJC-1295 with DAC and CJC-1295 without DAC?
Both compounds share the same 29-amino-acid GHRH 1-29 base sequence with four stability substitutions. The difference is the Drug Affinity Complex modification: CJC-1295 with DAC has a maleimidopropionic acid linker at the C-terminus that binds covalently to serum albumin, producing a functional half-life of six to eight days. CJC-1295 without DAC, also called Modified GRF 1-29 or Mod GRF 1-29, lacks the linker and has a much shorter half-life measured in minutes to hours. The two compounds are pharmacokinetically distinct and are not interchangeable in research applications. Research peptide commerce often sells the unqualified “CJC-1295” label for the DAC version, but methodology requires verifying which version is in the vial.
What is the CJC-1295 amino acid sequence?
The base sequence corresponds to human GHRH residues 1 through 29 with substitutions at positions 2, 8, 15, and 27. The N-terminal D-alanine substitution at position 2 blocks degradation by dipeptidyl peptidase IV, the primary enzymatic clearance mechanism for native GHRH. The remaining three substitutions further stabilize the peptide against proteolytic clearance. The DAC version adds a maleimidopropionic acid linker at the C-terminus that forms a covalent bond with cysteine-34 on serum albumin upon administration.
What model systems are most commonly used in CJC-1295 research?
In vivo rodent endocrinology preparations dominate the pre-clinical CJC-1295 research literature, with focus on growth hormone pharmacokinetics, IGF-1 axis dynamics, and parallel-arm methodology with other GH secretagogues. Clinical pharmacology research in healthy adults has characterized the human pharmacokinetic profile of the DAC version. In vitro pituitary cell preparations are used for direct GHRHR signaling readouts and dose-response characterization. The compound serves as a tool compound for broader GH-axis research as well as a direct investigational target.
What Is CJC-1295? GHRH Analog Research
What Is CJC-1295? GHRH Analog Research
Overview
What is CJC-1295? It is a synthetic 29-amino-acid analog of growth hormone releasing hormone (GHRH), developed by the Canadian biotechnology company ConjuChem and described in the published research literature as a long-acting GHRH receptor agonist. The compound has become one of the most extensively studied research peptides in the growth hormone axis category and the reference compound for parallel-arm research with ghrelin receptor agonists like Ipamorelin.
The name CJC-1295 encompasses two related but pharmacokinetically distinct compounds in research peptide commerce. CJC-1295 with DAC (Drug Affinity Complex) is the long-acting version, characterized by covalent attachment to serum albumin and a published half-life of approximately six to eight days. CJC-1295 without DAC, sometimes labeled Modified GRF (1-29) or Mod GRF 1-29, is the short-acting analog with a half-life measured in minutes to hours. The distinction is methodologically critical because the two compounds produce substantially different time courses of growth hormone release and require different experimental designs. This article uses CJC-1295 to refer to the DAC-modified version unless specifically noted, since the DAC variant is what most research peptide commerce supplies under the unqualified CJC-1295 label.
The biological activity profile that defines CJC-1295 in the published literature depends on the specific 29-amino-acid sequence, on the four substitution sites that confer enzymatic stability, and on the maleimidopropionic acid linker that mediates albumin binding in the DAC version. Synthesis errors, sequence variants, missing or improperly attached DAC linkers, and other defects can substantially alter the half-life and the time-integrated GHRH receptor stimulation in ways that phenotypic readouts often miss. The line between research-grade peptide commerce and gray-market pharmaceutical distribution runs through this verification step, since a CJC-1295 preparation whose DAC linker integrity is not analytically confirmed cannot be assumed to behave like the long-acting compound characterized across the published GH-axis pharmacology literature.
This article covers what CJC-1295 is at the structural and biochemical level, the relationship between CJC-1295 with DAC and the non-DAC analog, the GHRH receptor pharmacology and downstream signaling, the model systems most commonly used for CJC-1295 work, and the methodology considerations that govern rigorous in vitro and pre-clinical research with the compound. It sits within the GENEVIUM Research Hub coverage of growth hormone axis peptide research, in the Healing & Sleep pillar. The broader category context is treated in the Recovery Peptide Research overview, and the dedicated parallel comparison to the ghrelin receptor agonist Ipamorelin is covered in CJC-1295 vs Ipamorelin Research Comparison. For the broader research-use-only framework that governs all GENEVIUM peptides, see What Research Use Only Means.
What Is CJC-1295 at the Molecular Level
CJC-1295 is a synthetic analog of growth hormone releasing hormone, specifically a modified version of the biologically active 1-29 N-terminal fragment of human GHRH. The native GHRH sequence is 44 amino acids long, but functional GH-releasing activity is retained in the first 29 residues, which became the starting point for development of synthetic GHRH analogs in the 1980s and 1990s. CJC-1295 was developed by ConjuChem, a Canadian biotechnology company that pioneered the Drug Affinity Complex technology underlying the long-acting version of the compound.
Sequence and Substitutions
The base sequence of CJC-1295 corresponds to GHRH residues 1 through 29 with four substitution sites engineered to confer enzymatic stability against the proteases that rapidly degrade native GHRH in vivo. The substitutions are at positions 2 (D-alanine for stability against dipeptidyl peptidase IV), 8, 15, and 27. The result is a 29-amino-acid peptide that retains the GHRH receptor binding profile of the native hormone but is substantially more stable against systemic degradation than the unmodified GHRH 1-29 fragment.
The substitution at position 2, D-alanine in place of L-alanine, is particularly important. Dipeptidyl peptidase IV cleaves native GHRH at the N-terminus within minutes, eliminating biological activity. The D-alanine substitution at position 2 blocks this cleavage and is the single most important stability modification in CJC-1295.
The Drug Affinity Complex (DAC) Modification
CJC-1295 with DAC adds a maleimidopropionic acid linker at the C-terminus of the 29-amino-acid sequence. This linker contains a reactive maleimide group that forms a covalent thioether bond with the free thiol of cysteine-34 on serum albumin. The result is a peptide-albumin conjugate that circulates with a half-life approaching that of serum albumin itself, approximately nineteen to twenty days, although the practical functional half-life observed in published research is shorter at roughly six to eight days.
The DAC mechanism is what distinguishes the long-acting version from the non-DAC analog. CJC-1295 without DAC has the same 29-amino-acid sequence with the same four stability substitutions, but lacks the maleimidopropionic acid linker. Without the albumin binding mechanism, the peptide circulates freely and is cleared with a half-life of roughly thirty minutes to a few hours depending on the model system. The two compounds are biochemically related but pharmacokinetically very different, and the research literature treats them as distinct compounds for experimental purposes.
Synthesis and Stability
CJC-1295 is produced by solid-phase peptide synthesis using standard fluorenylmethoxycarbonyl (Fmoc) chemistry, followed by attachment of the maleimidopropionic acid linker at the C-terminus for the DAC version. The peptide is purified by reverse-phase HPLC to research-grade purity standards (typically minimum 99% by reverse-phase HPLC) and characterized by mass spectrometry to confirm sequence identity and DAC linker integrity. The synthesis route is established and well-documented, and CJC-1295 has become widely available as a research peptide as a result.
Solubility in aqueous research buffers is good. Standard reconstitution uses bacteriostatic water, and reconstituted CJC-1295 retains stability at refrigerator temperatures over the time course of typical research experiments. Long-term storage of lyophilized CJC-1295 is at minus 20 degrees Celsius or lower in dry conditions. Repeated freeze-thaw cycles should be avoided.
Proposed Mechanisms of Action
The mechanistic identity of CJC-1295 is rooted in GHRH receptor pharmacology. Unlike the multi-pathway tissue-repair peptides where the molecular target remains incompletely characterized, CJC-1295 has a clearly identified primary receptor target, well-characterized downstream signaling, and a quantitative relationship between receptor activation and growth hormone release. The mechanism is one of the most rigorously documented in the recovery peptide category.
GHRH Receptor Binding
CJC-1295 binds the growth hormone releasing hormone receptor (GHRHR), a class B G-protein-coupled receptor expressed primarily on somatotroph cells of the anterior pituitary gland. The receptor is the physiological target of native GHRH and mediates the hypothalamic control of growth hormone release. Substitutions and structural modifications in CJC-1295 preserve high-affinity binding to the GHRHR, which is the foundation of all downstream effects of the compound.
The binding kinetics of CJC-1295 with DAC differ from native GHRH and from the non-DAC analog in one important respect. Because the DAC version circulates bound to albumin, the effective free concentration available for receptor binding at any given moment is lower than the total circulating concentration. The molecule is delivered continuously to the receptor over the multi-day functional half-life rather than as a single high-concentration bolus. This time-integrated stimulation profile is the basis for the prolonged GH release effects observed in published research.
cAMP Signaling and Growth Hormone Release
GHRH receptor activation triggers a Gαs-coupled signaling cascade producing cyclic AMP, which activates protein kinase A, which phosphorylates the transcription factor CREB. CREB phosphorylation drives transcription of the growth hormone gene and contributes to the synthesis of new GH alongside the release of pre-stored GH from somatotroph secretory granules. The cAMP pathway is the canonical GHRH signaling mechanism and operates identically for native GHRH and for CJC-1295.
The functional consequence is increased growth hormone release from the pituitary into systemic circulation. This downstream GH then acts on hepatic GH receptors to stimulate IGF-1 production, on adipose tissue to promote lipolysis, and on multiple peripheral tissues for the broader anabolic and metabolic effects of GH-IGF-1 axis activation.
Preserved Pulsatility
One of the more counterintuitive findings in the published CJC-1295 literature concerns growth hormone pulsatility. Continuous GHRH receptor stimulation might be expected to produce sustained, non-pulsatile GH release, which would be undesirable because continuous GH exposure causes receptor downregulation and loss of biological effect. Published research using CJC-1295 has documented that the pulsatile pattern of GH release is preserved despite continuous receptor stimulation, mediated by the counter-regulatory action of hypothalamic somatostatin.
The preserved pulsatility means that CJC-1295 increases the amplitude of natural GH pulses rather than overriding them with a continuous release pattern. From a research methodology perspective, this is what makes CJC-1295 valuable as a tool compound for GH-axis research: the compound increases integrated GH exposure without disrupting the pulsatile signaling that downstream tissues are biologically tuned to receive.
Areas of Active CJC-1295 Research
Several distinct research areas use CJC-1295 as a primary investigational compound. Each is characterized by its own model systems and endpoints, and researchers new to CJC-1295 work benefit from understanding which areas have the strongest published evidence base.
Growth Hormone Pharmacokinetic Research
The foundational CJC-1295 research literature focuses on the pharmacokinetic and pharmacodynamic profile of the compound: how plasma concentrations rise and fall over time, how those concentrations relate to GH release, and how the pulsatile pattern of GH secretion responds to sustained receptor activation. Published clinical pharmacology studies in healthy adults established the multi-day functional half-life of the DAC version and characterized the integrated GH and IGF-1 response over the dosing interval.
GH-IGF-1 Axis Research
Beyond the immediate pharmacokinetic profile, CJC-1295 has been used as a tool compound for broader GH-IGF-1 axis research. The downstream effects of sustained GH receptor stimulation on hepatic IGF-1 production, on IGF binding protein expression, and on the systemic anabolic and metabolic markers of GH-axis activation are studied across both clinical research and pre-clinical animal models. The compound serves as a reproducible, long-acting stimulus that allows examination of GH-axis dynamics on a different time scale than is possible with short-acting GHRH analogs.
Parallel-Arm Research with Ghrelin Receptor Agonists
CJC-1295 is most commonly studied alongside Ipamorelin, a synthetic pentapeptide ghrelin receptor agonist, in parallel-arm research designs investigating combined or comparative effects of the two growth hormone secretagogue pathways. The mechanistic rationale is that CJC-1295 engages the GHRHR pathway while Ipamorelin engages the GHS-R1a (ghrelin receptor) pathway, and the two converge on growth hormone release through distinct upstream signaling that can be quantitatively dissected with parallel-arm experimental design.
Sleep Architecture and Growth Hormone Coupling
A smaller but distinct line of research examines the relationship between CJC-1295 administration and the sleep-coupled pattern of growth hormone release. Endogenous GH release is concentrated in the slow-wave sleep phases of the early night, and the interaction between sustained CJC-1295-mediated GHRHR stimulation and this physiologically pulsatile sleep-coupled release has been studied in the context of broader sleep-and-restoration research.
Research Methodology and Quality Standards
CJC-1295 research is sensitive to compound purity and identity confirmation, with one verification consideration that does not apply to most other research peptides. The DAC linker integrity is an additional analytical checkpoint beyond the standard 29-amino-acid sequence verification, and the theoretical molecular weight of CJC-1295 with DAC differs from CJC-1295 without DAC by the mass of the maleimidopropionic acid linker. Mass spectrometry confirmation must match the documented version on the Certificate of Analysis, and material whose mass profile is intermediate between the two versions has either incomplete DAC attachment or contamination with the non-DAC analog.
Published research consistently uses minimum 99% purity by reverse-phase HPLC, with mass spectrometric identity confirmation matching the theoretical molecular weight for the specific version (DAC or non-DAC), as the standard threshold for growth hormone axis peptide work. The methodology distinction between the two versions is not optional. Research designs intended to study the long-acting compound cannot accept material whose DAC integrity is unverified, and research designs intended to study the short-acting Modified GRF 1-29 cannot accept material contaminated with the DAC version. Suppliers shipping CJC-1295 under loose labeling without documenting which version is in the vial are not operating to research-grade standards regardless of the headline purity figure.
Reconstitution methodology should be standardized within and across studies. Bacteriostatic water is the most common reconstitution medium. The final concentration and the time elapsed between reconstitution and use should be reported in published research, since stability over hours to days at refrigerator temperature is good but not unlimited. Repeated freeze-thaw cycles should be avoided. For a detailed treatment of lyophilization, storage temperatures, and quality indicators researchers use to assess lyophilized peptide material before reconstitution, see Lyophilized Peptides: Methodology and Stability. For the analytical chemistry behind HPLC peptide verification, including the chromatogram interpretation skills required to verify DAC linker integrity by retention time, see HPLC Peptide Verification.
Standard model systems for CJC-1295 research include in vivo rodent endocrinology preparations for pharmacokinetic and pharmacodynamic characterization, in vitro pituitary cell preparations for direct GHRHR signaling readouts, and clinical pharmacology designs for the human pharmacokinetic literature. GH release into the systemic circulation is the primary readout for most CJC-1295 research, with IGF-1 measurement as the secondary downstream marker. Cell-based assays should specify the pituitary cell preparation used and the GH release assay methodology, since baseline pulsatility characteristics vary significantly across preparations.
GENEVIUM publishes a batch-specific Certificate of Analysis for every research peptide and makes them retrievable by batch number on the COA Lookup Page.
The growth hormone axis pharmacology that distinguishes CJC-1295 in the published literature only holds for material whose 29-amino-acid sequence integrity, four stability substitutions, and DAC linker (for the long-acting version) are analytically confirmed on each batch. A supplier that documents sequence purity, mass-spectrometric identity, and DAC linker integrity on a batch-specific Certificate of Analysis retrievable by lot number is operating on the research-grade side of the line between legitimate research peptide commerce and gray-market pharmaceutical distribution. A supplier that ships CJC-1295 under loose nomenclature without specifying the DAC or non-DAC version, or that aggregates purity across batches without lot-level documentation, is not, regardless of the headline purity figure displayed at point of sale.
Frequently Asked Questions
What does CJC-1295 stand for?
CJC stands for ConjuChem, the Canadian biotechnology company that developed the compound. The 1295 designation is an internal compound numbering convention from ConjuChem product development records and does not encode chemical or sequence information. CJC-1295 was first characterized in the published research literature in the mid-2000s, with the foundational human pharmacokinetic study published by Teichman and colleagues in 2006.
What is the difference between CJC-1295 with DAC and CJC-1295 without DAC?
Both compounds share the same 29-amino-acid GHRH 1-29 base sequence with four stability substitutions. The difference is the Drug Affinity Complex modification: CJC-1295 with DAC has a maleimidopropionic acid linker at the C-terminus that binds covalently to serum albumin, producing a functional half-life of six to eight days. CJC-1295 without DAC, also called Modified GRF 1-29 or Mod GRF 1-29, lacks the linker and has a much shorter half-life measured in minutes to hours. The two compounds are pharmacokinetically distinct and are not interchangeable in research applications. Research peptide commerce often sells the unqualified “CJC-1295” label for the DAC version, but methodology requires verifying which version is in the vial.
What is the CJC-1295 amino acid sequence?
The base sequence corresponds to human GHRH residues 1 through 29 with substitutions at positions 2, 8, 15, and 27. The N-terminal D-alanine substitution at position 2 blocks degradation by dipeptidyl peptidase IV, the primary enzymatic clearance mechanism for native GHRH. The remaining three substitutions further stabilize the peptide against proteolytic clearance. The DAC version adds a maleimidopropionic acid linker at the C-terminus that forms a covalent bond with cysteine-34 on serum albumin upon administration.
What model systems are most commonly used in CJC-1295 research?
In vivo rodent endocrinology preparations dominate the pre-clinical CJC-1295 research literature, with focus on growth hormone pharmacokinetics, IGF-1 axis dynamics, and parallel-arm methodology with other GH secretagogues. Clinical pharmacology research in healthy adults has characterized the human pharmacokinetic profile of the DAC version. In vitro pituitary cell preparations are used for direct GHRHR signaling readouts and dose-response characterization. The compound serves as a tool compound for broader GH-axis research as well as a direct investigational target.