CJC-1295 with DAC

CJC-1295 with DAC 5mg

CJC-1295 with DAC is a long-acting synthetic peptide developed for research into the regulation of growth hormone secretion. It is a modified analogue of growth hormone-releasing hormone (GHRH) that was engineered to produce prolonged activation of the pituitary GHRH receptor, enabling researchers to investigate sustained stimulation of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis.

Researchers within the European Union can purchase CJC-1295 with DAC 5 mg from Crystal Peptides as a high-purity research compound independently tested by accredited laboratories, with batch-specific Certificates of Analysis available to verify identity and analytical quality.

This peptide is well suited for researchers because native human GHRH is rapidly degraded in circulation, giving it a plasma half-life of only a few minutes. CJC-1295 was designed to overcome this limitation through targeted amino acid substitutions that improve enzymatic stability. Specifically, CJC-1295 with DAC is formulated with the addition of a Drug Affinity Complex (DAC), which extends circulation time by enabling more stable covalent binding to serum albumin. This addition makes the peptide capable of maintaining biological activity for days rather than minutes.

What is CJC-1295 with DAC peptide?

CJC-1295 peptide is a synthetic peptide analogue derived from the biologically active N-terminal region of GHRH, which contains the receptor-binding sequence responsible for stimulating growth hormone release from anterior pituitary somatotrophs. Several amino acid substitutions were introduced to reduce susceptibility to enzymatic degradation while preserving receptor affinity, allowing CJC-1295 to retain the pharmacological profile of GHRH while exhibiting markedly improved stability under physiological conditions.

In CJC-1295 with DAC, the Drug Affinity Complex is added to the main molecule. DAC is not a separate carrier protein or formulation ingredient. Rather, it is a reactive maleimidopropionamide group attached directly to the peptide that forms a stable covalent bond with a free cysteine residue on circulating albumin after administration. Albumin functions as a naturally abundant transport protein, protecting the peptide from rapid renal clearance and enzymatic degradation while gradually releasing the active molecule over time.

This albumin-binding strategy extends the elimination half-life from minutes to approximately one week, distinguishing CJC-1295 with DAC from short-acting GHRH analogues.

What’s the difference between CJC-1295 with DAC, CJC-1295 no DAC, and Modified GRF (1-29)?

The terminology surrounding this peptide is often confusing because different names are used throughout the scientific literature and the research peptide market. Modified GRF (1-29) is the scientific name for the four-substitution GHRH analogue that is commonly marketed as CJC-1295 without DAC or CJC-1295 no DAC. These names refer to the same peptide.

CJC-1295 with DAC was subsequently developed by ConjuChem by attaching a Drug Affinity Complex (DAC) to the Modified GRF (1-29) peptide. The DAC enables stable covalent binding to circulating serum albumin, dramatically extending the peptide's residence time in circulation. Consequently, CJC-1295 with DAC and Modified GRF (1-29) share the same modified GHRH peptide backbone and receptor pharmacology but differ substantially in their pharmacokinetic profiles, with the DAC formulation exhibiting a half-life measured in days rather than minutes. This distinction is fundamental and should be maintained when interpreting published research.

Despite these pharmacokinetic differences, both compounds share the same fundamental mechanism of action. Unlike recombinant human growth hormone (rHGH), which acts directly on peripheral growth hormone receptors, both Modified GRF (1-29) and CJC-1295 with DAC act upstream within the endocrine signalling cascade by activating the growth hormone-releasing hormone receptor (GHRHR). This stimulates endogenous growth hormone secretion while preserving normal physiological feedback mechanisms, allowing researchers to investigate regulation of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis, pulsatile hormone release, and endocrine signalling.

The prolonged pharmacokinetic profile of CJC-1295 with DAC makes it particularly well suited to studies investigating sustained GHRH receptor activation.

Chemical properties and registry information

A few points are worth noting because they are frequently reported incorrectly.

CJC-1295 with DAC is a 30-amino-acid peptide. Although derived from human growth hormone-releasing hormone (GHRH), it is not the full-length 44-residue hormone but an engineered analogue based on its biologically active N-terminal region.

The molecular weight above applies specifically to the DAC version. Modified GRF (1-29), often marketed as "CJC-1295 no DAC," lacks the Drug Affinity Complex and therefore has a lower molecular weight and markedly different pharmacokinetic properties.

The Drug Affinity Complex is an integral part of the molecule. It is not supplied separately or pre-bound to albumin. Following administration, the maleimidopropionamide group reacts with circulating serum albumin, forming a stable covalent bond that greatly extends the peptide's residence time in circulation. This albumin-binding strategy is the defining feature that distinguishes CJC-1295 with DAC from short-acting GHRH analogues.

Here's a revised version that more closely matches the style of the Cagrilintide page. It focuses on the small but meaningful clinical evidence base, avoids artificially inflating the number of studies, and highlights what each paper contributed.

CJC-1295 with DAC Clinical data

The published clinical literature on CJC-1295 with DAC is relatively limited but unusually informative. Unlike many research peptides, CJC-1295 completed multiple early-phase studies examining its pharmacokinetics, pharmacodynamics, endocrine effects, and safety before development was discontinued. Most of the available evidence therefore concerns growth hormone physiology rather than long-term therapeutic outcomes.

Phase 1 clinical programme (Teichman et al., Journal of Clinical Endocrinology & Metabolism, 2006)

Twenty-four healthy adults participated in a dose-escalation study evaluating both single and repeated subcutaneous administration of CJC-1295. Single doses ranging from 30 to 1,000 µg/kg produced sustained, dose-dependent increases in circulating growth hormone concentrations for six days or longer and elevated plasma IGF-1 concentrations for approximately 9 to 11 days. The estimated elimination half-life ranged from 5.8 to 8.1 days, reflecting the prolonged albumin-binding properties of the Drug Affinity Complex. During the multiple-dose portion of the study, repeated weekly administration maintained elevated IGF-1 concentrations for up to 28 days, demonstrating a cumulative pharmacodynamic effect without evidence of tachyphylaxis. CJC-1295 was generally well tolerated, with mild injection-site reactions, flushing, and headache representing the most commonly reported treatment-related observations. [1]

Growth hormone pulsatility study (Ionescu et al., Journal of Clinical Endocrinology & Metabolism, 2006)

One of the central questions surrounding long-acting GHRH analogues is whether sustained receptor stimulation suppresses the normal pulsatile pattern of endogenous growth hormone secretion. Detailed endocrine profiling demonstrated that CJC-1295 significantly increased mean growth hormone secretion, through growth hormone concentrations, and circulating IGF-1 while preserving physiological pulsatility. Rather than replacing endogenous hormone release with continuous stimulation, the peptide amplified naturally occurring secretory pulses, distinguishing it mechanistically from exogenous recombinant growth hormone administration.[2]

Taken together, these studies established the defining pharmacological characteristics of CJC-1295 with DAC. Native GHRH has a circulating half-life measured in minutes, whereas the albumin-binding Drug Affinity Complex extends biological activity to approximately one week while preserving endogenous pituitary regulation. This combination of prolonged exposure and physiological hormone release remains the principal scientific rationale for the compound and explains its continued use as a research tool for investigating the growth hormone/IGF-1 axis.

Beyond these early investigations, published human data are limited. Later work has primarily examined downstream biomarkers of GH/IGF-1 activation rather than clinical efficacy, demonstrating measurable changes in serum protein expression following CJC-1295 administration and providing additional insight into the biological consequences of sustained GHRH receptor activation. [3]

Development of CJC-1295 did not progress to regulatory approval or marketing authorisation in any region. Although the compound entered Phase II clinical development, the programme was discontinued, and no formulation of CJC-1295 with DAC has been approved by the European Medicines Agency (EMA), the U.S. Food and Drug Administration (FDA), or any other national medicines regulator.

Current understanding of the peptide is therefore derived from published pharmacology and early-phase clinical investigations rather than approved therapeutic use.

CJC-1295 with DAC Research applications

CJC-1295 with DAC is a widely used research tool for investigating long-term activation of the growth hormone-releasing hormone (GHRH) receptor and the physiological regulation of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis. The compound’s prolonged half-life distinguishes it from native GHRH and short-acting analogues, allowing researchers to examine sustained endocrine signalling while preserving endogenous pituitary function.

Growth hormone and IGF-1 axis regulation

CJC-1295 provides a model for studying prolonged stimulation of the GHRH receptor and its downstream effects on growth hormone and IGF-1 secretion. Because the peptide stimulates endogenous hormone release instead of replacing growth hormone directly, it is frequently used to investigate endocrine feedback mechanisms, pituitary responsiveness, and the physiological regulation of the somatotropic axis over extended periods.

Pulsatile growth hormone secretion

One of the defining characteristics of CJC-1295 is its ability to sustain endocrine activity without abolishing the normal pulsatile pattern of growth hormone release. This has made the peptide an important experimental tool for examining how prolonged GHRH receptor activation influences pulse frequency, pulse amplitude, and hypothalamic-pituitary feedback while maintaining physiological secretory rhythms.

Albumin-binding drug delivery systems

The Drug Affinity Complex represents one of the earliest successful applications of stable albumin binding to extend peptide half-life. Beyond endocrinology, CJC-1295 is referenced in research investigating albumin-mediated drug delivery, peptide pharmacokinetics, and strategies for prolonging the systemic exposure of biologically active peptides without continuous infusion or frequent dosing.

Comparative endocrinology

CJC-1295 is frequently evaluated alongside other compounds that influence the growth hormone axis, including Sermorelin, Modified GRF (1-29), and growth hormone secretagogues such as Ipamorelin. Comparative studies continue to examine differences in receptor activation, duration of action, endocrine responses, and interactions between GHRH receptor agonists and ghrelin receptor agonists, providing insight into the complementary roles of these signalling pathways.

Biomarker discovery and protein expression

Sustained activation of the GH/IGF-1 axis produces measurable changes in circulating proteins involved in growth, metabolism, inflammation, and tissue remodelling. Proteomic analyses following CJC-1295 administration have identified alterations in multiple serum biomarkers, making the compound a useful tool for investigating downstream molecular responses to prolonged endocrine stimulation and for identifying candidate biomarkers associated with growth hormone signalling.

How CJC-1295 with DAC works (mechanism of action)

CJC-1295 with DAC is a long-acting agonist of the growth hormone-releasing hormone receptor (GHRHR), a Class B G protein-coupled receptor expressed primarily on somatotroph cells of the anterior pituitary. By binding to this receptor, the peptide stimulates endogenous growth hormone secretion through the same physiological pathway as native GHRH while remaining in circulation for substantially longer due to its albumin-binding Drug Affinity Complex.

Target engagement

Under normal physiological conditions, hypothalamic GHRH binds the GHRH receptor on pituitary somatotrophs, initiating the release of stored growth hormone. Native GHRH is rapidly degraded by circulating proteases, limiting receptor activation to a matter of minutes. CJC-1295 preserves the receptor-binding properties of GHRH while incorporating amino acid substitutions that improve metabolic stability. The attached Drug Affinity Complex further prolongs exposure by forming a stable covalent bond with circulating serum albumin, maintaining plasma concentrations over several days. [4]

Downstream signalling pathways

Activation of the GHRH receptor primarily stimulates the Gs signalling pathway, leading to activation of adenylate cyclase, increased intracellular cyclic AMP (cAMP), and subsequent activation of protein kinase A (PKA). These signalling events promote growth hormone synthesis, storage, and secretion from pituitary somatotrophs. Additional downstream pathways, including CREB-mediated gene transcription and calcium-dependent secretory mechanisms, contribute to sustained endocrine responses following receptor activation. [5]

Endocrine effects

Growth hormone released in response to CJC-1295 acts on multiple peripheral tissues, most notably the liver, where it stimulates the synthesis and release of insulin-like growth factor-1 (IGF-1). Growth hormone also exerts direct metabolic effects independent of IGF-1, making the peptide a useful model for distinguishing primary growth hormone signalling from downstream IGF-1-mediated physiology. Because CJC-1295 acts upstream of growth hormone secretion rather than replacing the hormone itself, endocrine feedback mechanisms involving somatostatin and circulating IGF-1 remain intact. [3]

Preservation of physiological hormone secretion

One of the defining characteristics of CJC-1295 with DAC is that prolonged receptor stimulation does not produce continuous growth hormone release. Clinical investigations have demonstrated that endogenous secretion remains pulsatile despite sustained receptor activation, with the peptide amplifying naturally occurring secretory pulses rather than overriding them. This distinguishes CJC-1295 from exogenous recombinant growth hormone and makes it particularly valuable for investigating physiological regulation of the growth hormone/IGF-1 axis. [2]

Pharmacokinetic advantage of DAC

The Drug Affinity Complex fundamentally changes the behaviour of the peptide in circulation. Rather than increasing receptor potency, the DAC modification prolongs systemic exposure by reducing renal clearance and protecting the peptide from rapid enzymatic degradation through covalent binding to circulating serum albumin. This pharmacokinetic strategy extends the elimination half-life to approximately one week, allowing researchers to study prolonged GHRH receptor activation without the frequent administration required for native GHRH or short-acting analogues such as Modified GRF (1-29).

CJC-1295 with DAC compared to related research compounds

CJC-1295 with DAC belongs to the family of growth hormone-releasing hormone (GHRH) analogues, but it is frequently grouped with compounds that act through entirely different mechanisms. Some stimulate the GHRH receptor, others activate the ghrelin receptor, while recombinant growth hormone bypasses the pituitary altogether. Understanding where each compound acts within the growth hormone axis is more informative than comparing potency or duration alone.

The comparison is best understood by considering where each compound acts within the endocrine axis. CJC-1295 with DAC, Modified GRF (1-29), and Sermorelin all stimulate the same receptor but differ markedly in pharmacokinetics. Sermorelin most closely resembles endogenous GHRH, Modified GRF (1-29) improves stability while remaining short acting, and CJC-1295 with DAC extends receptor activation for approximately one week through albumin binding.

Ipamorelin occupies a different position altogether because it activates the growth hormone secretagogue receptor (GHSR-1a) or the ghrelin receptor, not the GHRHR. However, since these signalling pathways are complementary, the two classes of compounds are frequently evaluated together in experimental models investigating endogenous growth hormone regulation.

Quality and testing

Every batch of CJC-1295 with DAC supplied by Crystal Peptides is tested using analytical methods such as high-performance liquid chromatography (HPLC). These tests are conducted by independent, third-party labs such as Janoshik, with a Certificate of Analysis available on the product pages or our dedicated Lab Tests page. These COAs can be verified with the testing lab, giving researchers a higher standard of traceability compared to other companies that use shared documentation.

In particular, long-acting peptide analogues present analytical considerations beyond simple purity measurement. The Drug Affinity Complex present in this formulation contributes significantly to the molecular identity of CJC-1295 with DAC, making confirmation by mass spectrometry particularly valuable together with chromatographic purity testing.

However, note that a high score on the HPLC test is not sufficient to distinguish CJC-1295 with DAC from shorter GHRH analogues or confirm the presence of the albumin-binding modification.

Handling and storage also play an important role in preserving peptide integrity. Although CJC-1295 with DAC is substantially more stable than native GHRH, peptide degradation may still occur following repeated freeze-thaw cycles, prolonged exposure to elevated temperatures, or inappropriate reconstitution practices.

This research material is supplied in lyophilised (freeze-dried) form and should remain sealed until use. Reconstituted solutions should be stored under appropriate refrigerated conditions to minimise degradation over time.

Regulatory and legal

All products supplied by Crystal Peptides are intended strictly for research and development purposes. These materials are supplied exclusively as laboratory reagents for scientific investigation and are not authorised for use in humans or animals.

This product is not a medicinal product, food, food supplement, medical device, or cosmetic. CJC-1295 with DAC has not been authorised as a medicinal product by the European Medicines Agency (EMA), the U.S. Food and Drug Administration (FDA), or any other national medicines regulator.

Although the compound entered early clinical development and demonstrated prolonged stimulation of endogenous growth hormone and insulin-like growth factor-1 secretion, clinical development did not ultimately result in marketing authorisation. Any statements regarding the compound are derived from published scientific literature and have not been evaluated by any regulatory authority. These materials are not intended to diagnose, treat, cure, or prevent any disease.

Materials must be handled only by appropriately qualified professionals trained in laboratory research procedures. Introduction of this product into humans or animals is prohibited and may breach applicable laws and regulations. As the buyer, you are responsible for ensuring that all acquisition, importation, storage, handling, use, and disposal complies with the legislation applicable in their jurisdiction. National requirements governing research chemicals differ between countries.

LABORATORY REAGENT, FOR RESEARCH PURPOSES ONLY. Not a medicinal product or food. Not for human consumption.

Sources and references

Teichman SL, Neale A, Lawrence B, et al. 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. 2006;91(3):799-805. PMID: 16352683

Ionescu M, Frohman LA. 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. 2006;91(12):4792-4797. PMID: 17018654

Sackmann-Sala L, Ding J, Frohman LA, et al. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth Hormone & IGF Research. 2009;19(6):471-477. PMID: 19386527

Dieguez C, López M, Casanueva F. Hypothalamic GHRH. Reviews in Endocrine and Metabolic Disorders. 2025;26(3):297-303. PMID: 39913072

Halmos G, Szabo Z, Dobos N, et al. Growth hormone-releasing hormone receptor (GHRH-R) and its signaling. Reviews in Endocrine and Metabolic Disorders. 2025;26(3):343-352. PMID: 39934495

Frequently Asked Questions

What is CJC-1295 with DAC?

CJC-1295 with DAC is a long-acting synthetic analogue of growth hormone-releasing hormone (GHRH) developed for endocrine and peptide research. It stimulates the growth hormone-releasing hormone receptor (GHRHR) in the anterior pituitary, promoting endogenous growth hormone secretion while preserving physiological endocrine feedback. Unlike short-acting GHRH analogues, it incorporates a Drug Affinity Complex (DAC) that prolongs systemic exposure through stable covalent binding to circulating serum albumin, making it a valuable research tool for investigating sustained activation of the GH/IGF-1 axis.

What is the difference between CJC-1295 with DAC and CJC-1295 without DAC?

The principal difference is the presence of the Drug Affinity Complex. Modified GRF (1-29), also known as CJC-1295 without DAC or CJC-1295 no DAC, contains the same modified GHRH peptide backbone but does not incorporate the albumin-binding DAC modification. As a result, CJC-1295 without DAC has a circulating half-life measured in minutes, whereas CJC-1295 with DAC remains in circulation for approximately one week. Although both peptides activate the same receptor and share the same fundamental mechanism of action, their pharmacokinetic profiles and research applications differ substantially.

How does CJC-1295 with DAC work?

CJC-1295 with DAC acts as an agonist of the growth hormone-releasing hormone receptor (GHRHR) located on somatotroph cells of the anterior pituitary. Activation of this receptor stimulates endogenous growth hormone synthesis and secretion through the normal hypothalamic-pituitary signalling pathway. Clinical studies have shown that despite its prolonged circulation time, the peptide preserves physiological pulsatile growth hormone secretion rather than replacing it with continuous exogenous hormone exposure.

What clinical studies have been published on CJC-1295 with DAC?

The most influential human studies were published in the Journal of Clinical Endocrinology & Metabolism in 2006. These Phase I investigations demonstrated sustained increases in circulating growth hormone and insulin-like growth factor-1 (IGF-1) following administration of CJC-1295 with DAC while preserving physiological pulsatile hormone secretion. Subsequent research has explored changes in serum protein profiles associated with activation of the GH/IGF-1 axis, contributing to a broader understanding of the peptide's pharmacology and endocrine effects.

Why did CJC-1295 with DAC not receive marketing authorisation?

Although CJC-1295 with DAC progressed through early clinical development and demonstrated favourable pharmacokinetic and pharmacodynamic properties, development did not continue through to marketing authorisation. Consequently, the published evidence remains limited to early-phase clinical investigations and laboratory research, and the compound has not been authorised as a medicinal product by the European Medicines Agency (EMA) or other major medicines regulators.

Is CJC-1295 with DAC supplied for research use only?

Yes. Crystal Peptides supplies CJC-1295 with DAC exclusively as a laboratory research reagent. The product is intended solely for scientific investigation and is not a medicinal product, food, food supplement, or veterinary product. It is not intended to diagnose, treat, cure, or prevent any disease and must not be used in humans or animals.

Does Crystal Peptides provide a Certificate of Analysis (COA)?

Yes. Every batch is supplied with a batch-specific Certificate of Analysis that can be traced directly to the independent testing laboratory. The COA allows researchers to verify the identity, purity, and analytical characteristics of the exact batch supplied before it is incorporated into experimental work. Crystal Peptides also maintains a dedicated COA library where researchers can review analytical documentation for individual batches.

How is CJC-1295 with DAC tested?

Each product sold by Crystal Peptides undergoes comprehensive quality control before release. Analytical testing includes HPLC purity analysis, molecular identity verification, and independent third-party testing by accredited laboratories such as Janoshik Analytical. Depending on the product and batch, additional testing may include peptide content, endotoxin, sterility, and heavy metal screening, providing researchers with confidence in the quality, identity, and reproducibility of the material supplied.

What vial size does Crystal Peptides offer?

Crystal Peptides currently supplies CJC-1295 with DAC in 5 mg lyophilised research vials. Current availability, pricing, and supporting analytical documentation are displayed on the product page. Crystal Peptides also supplies CJC-1295 no DAC in 5mg and 10mg vials; get CJC-1295 peptide for sale in a high-purity formulation verified through independent testing.

How should CJC-1295 with DAC be reconstituted and stored?

CJC-1295 with DAC is supplied as a lyophilised powder and is typically reconstituted in laboratory settings using bacteriostatic water or sterile water. The diluent should be introduced slowly along the inside wall of the vial, allowing the peptide to dissolve naturally without vigorous agitation. After reconstitution, the solution should be refrigerated at 2–8°C and protected from repeated freeze-thaw cycles. Unreconstituted vials should be stored sealed, dry, protected from light, and preferably at -20°C or below until required for research.

Where can I buy CJC-1295 5mg with DAC in Europe?

If you’re located within the European Union, you can buy CJC-1295 with DAC 5mg from Crystal Peptides at very high purity and quality. Every batch is independently tested by accredited labs and every batch is accompanied by a Certificate of Analysis. Note that this is a research compound shipped within the EU for laboratory research purposes only, providing high-purity peptides to support research in educational institutions, laboratories, and independent researchers.

Does Crystal Peptides ship CJC-1295 with DAC across Europe?

Yes. Crystal Peptides ships research peptides throughout Europe using tracked delivery services and discreet packaging. Orders are typically dispatched quickly, with delivery times varying by destination country, and express shipping is available for many locations. Researchers can review estimated delivery times, shipping options, and payment methods, including major card providers and other supported payment solutions, before placing an order. Buy CJC-1295 with DAC 5mg from Crystal Peptides; full shipping information and country-specific delivery guidance are available upon request.