CJC-1295: DAC vs No-DAC Structure & Half-Life

In the world of peptide research, Growth Hormone-Releasing Hormones (GHRH) and their synthetic analogs play a central role. They offer exciting opportunities for studying the regulation of the endocrine system and potential therapeutic strategies. Among these GHRH analogs, CJC-1295 is one of the most researched peptides, providing scientists with deep insights into influencing growth hormone secretion. This detailed research article by One Plus Labs highlights the structural and pharmacokinetic differences between CJC-1295 with and without Drug Affinity Complex (DAC) and discusses their implications for scientific research.

The focus is on the molecular intricacies that lead to drastically different half-lives, the precise analytics to ensure research quality, and the diverse research applications that make these peptides attractive to laboratories worldwide. For more information on GHRH analogs and their role in research, visit our article on GHRH Analogs Compared.

1. Introduction: GHRH Analogs and why CJC-1295 is one of the most researched peptides

Growth Hormone-Releasing Hormone (GHRH) is a hypothalamic peptide that stimulates the secretion of growth hormone (GH) from the pituitary gland. Its short half-life in the bloodstream has driven the development of GHRH analogs that enable prolonged GH release. CJC-1295, a synthetic 30-amino acid peptide, is derived from GHRH and was developed to achieve a longer-lasting effect. It has established itself as a key molecule in the study of GH endocrinology, as it maintains the pulsatility of GH release while increasing overall GH exposure. The two main variants of CJC-1295, with and without the DAC complex, offer researchers different pharmacokinetic profiles that can be precisely tailored to specific experimental requirements. These customized properties make CJC-1295 an indispensable tool in peptide research, from studying aging-associated GH deficits to investigating metabolic diseases.

2. Molecular Structure: CJC-1295 with DAC vs. without DAC (Mod GRF 1-29)

The distinction between CJC-1295 with DAC (Drug Affinity Complex) and without DAC, often referred to as Mod GRF 1-29, lies in a crucial molecular modification. Both peptides are derived from the first 29 amino acid sequence of GHRH, which is essential for the physiological activity of GHRH.

2.1. Amino Acid Sequence and Modifications

The original GHRH sequence consists of 44 amino acids. Mod GRF 1-29, also known as Sermorelin, is a truncated version comprising only the first 29 amino acids of the GHRH chain. However, in research literature, a modified form of GRF 1-29 is often used, which replaces the amino acids Asparagine (Asn) with Alanine (Ala) at position 2 and Serine (Ser) with Glycine (Gly) at position 8 to reduce enzymatic degradation and thus improve stability. This modification results in a peptide known as Mod GRF 1-29 or CJC-1295 without DAC. The sequence is: Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2.

2.2. DAC Conjugation and Albumin Binding

The crucial modification that distinguishes CJC-1295 with DAC from Mod GRF 1-29 is the conjugation of a maleimidopropyl-based ligand to the peptide via a lysine amino acid. This chemical modification enables covalent binding to endogenous albumin, a protein abundant in the blood. Albumin, with a half-life of approximately 19 days in the human body, serves as a carrier protein and protects the peptide from rapid enzymatic degradation and renal clearance.

The exact amino acid sequence of CJC-1295 with DAC is the same as that of modified GRF 1-29, but a maleimidopropyldimethylglutarimidyl chain (or a similar structure) is attached at the lysine position (usually position 15). This DAC technology, also known as "Drug Affinity Complex" technology, was specifically developed to improve the pharmacokinetics of peptides by utilizing blood plasma proteins, especially albumin, as quasi-endogenous long-term depots.

Conjugation to albumin has several advantages for research:

• Extended half-life: Binding protects the peptide from rapid enzymatic degradation.
• Reduced renal clearance: Albumin-bound molecules are excreted more slowly by the kidneys.
• Steady release: The peptide is slowly released from the albumin complex, leading to a sustained effect.

These structural differences are fundamental to understanding the pharmacokinetic and pharmacodynamic profiles of both peptide variants and guide the selection of the appropriate peptide for specific research designs.

3. Pharmacokinetics: Half-Life Comparison and Release Profile

The pharmacokinetics of a peptide, particularly its half-life and release profile, are crucial factors for designing research studies. CJC-1295 with and without DAC show significant differences here, which result directly from their molecular structures.

3.1. Half-Life of Mod GRF 1-29 (CJC-1295 without DAC)

Mod GRF 1-29, the version without DAC modification, has a relatively short plasma half-life. After subcutaneous or intravenous administration, a half-life of approximately 30 minutes to a few hours has been observed in various preclinical and clinical studies (Ionescu M & Bhatt DL, 2006, DOI: 10.1210/jc.2005-2017). This short residence time in the body is typical for many native peptides and is due to rapid enzymatic degradation by peptidases and swift renal elimination.

For research purposes, this means that Mod GRF 1-29 induces pulsatile release of growth hormone, closely mimicking physiological GHRH pulses. For studies investigating short-term, physiologically imitative GH inductions, or for experiments requiring precise control over the timing and duration of GH release, Mod GRF 1-29 is the preferred choice.

3.2. Half-Life of CJC-1295 with DAC

In contrast, CJC-1295 with DAC benefits from the aforementioned conjugation to albumin. This binding effectively protects the peptide from degradation and excretion. The result is a dramatically extended half-life. Research has shown that CJC-1295 with DAC can achieve a half-life of up to 6-8 days (Teichman SL et al., 2006, PMID: 16352683; Alba M et al., 2006, PMID: 16352686).

This significantly extended half-life leads to a sustained release profile. After a single administration, the peptide is slowly released from the albumin complex over several days, resulting in continuous GHRH receptor stimulation. For research designs that investigate a long-lasting and stable increase in growth hormone levels and associated subsequent effects on Insulin-like Growth Factor 1 (IGF-1) over several days to weeks, CJC-1295 with DAC is the peptide of choice. It enables the study of chronic effects of GH on metabolism, tissue regeneration, and aging phenomena without the need for frequent administrations.

3.3. Implications for Research

The choice between CJC-1295 with DAC and without DAC strongly depends on the research question:

• Mod GRF 1-29 (CJC-1295 without DAC) is suitable for studies that aim to investigate the acute and pulsatile modulation of GH secretion. This can be relevant for experiments examining the direct effects of GH pulses on target tissues or analyzing the short-term regulation of the hypothalamic-pituitary axis.
• CJC-1295 with DAC is ideal for long-term studies where a constant, elevated GH exposure over several days is required. This is particularly useful for investigating chronic effects on metabolism, body composition, bone density, or wound healing. It also reduces experimental burden through less frequent administrations.

Both variants are valuable tools in peptide research, allowing researchers to unravel the complex mechanisms of growth hormone regulation with high precision.

4. Research Applications: In-vitro GH Release, Combination with Ipamorelin in Research, GHRP Synergy

The precise and distinct pharmacokinetic profiles of CJC-1295 with and without DAC open up diverse research applications. These peptides are indispensable tools in endocrinology and metabolic research.

4.1. In-vitro GH Release Studies

In-vitro studies play a crucial role in investigating the cellular mechanisms of growth hormone release. Pituitary cells or immortalized somatotrophic cell lines are often used here.

• Mod GRF 1-29 (CJC-1295 without DAC) is ideal for acute in-vitro experiments due to its short half-life and direct GHRH receptor binding. Researchers can investigate concentration-response relationships, measure the kinetics of GH release, and analyze the signal transduction pathways (e.g., cAMP pathway) triggered by GHRH receptor activation. Rapid clearance allows for observing cellular responses to short-term stimuli and investigating the reversibility of effects.
• CJC-1295 with DAC is less suited for in-vitro studies, as the DAC component is primarily designed for interaction with serum albumin in the systemic circulation. In cell-based assays that do not have an albumin-rich medium, the extended half-life property would not be effective. Nevertheless, it could be useful in specific experiments investigating the interaction of the peptide with albumin or similar proteins in a defined environment.

4.2. Combination with Ipamorelin in Research: GHRP Synergy

A particularly potent research approach is the synergistic administration of GHRH analogs and Growth Hormone-Releasing Peptides (GHRPs). GHRPs act via a separate receptor, the ghrelin receptor (GHSR-1a), and additionally stimulate GH release through other mechanisms, including the suppression of somatostatin.

Ipamorelin is a selective GHRP valued in research for its high specificity for the GHSR-1a receptor and its low impact on prolactin or cortisol levels. The co-administration of CJC-1295 (DAC or without DAC) and Ipamorelin has been shown in research models to stimulate GH release significantly more strongly than the application of either peptide alone. This is referred to as GHRP synergy.

• The combination of Mod GRF 1-29 (CJC-1295 without DAC) and Ipamorelin allows researchers to mimic short-term, maximized GH release, referred to as a "super-pulse." This is relevant for studies investigating the body's acute response to enhanced GH stimulation, for example, in models of muscle regeneration or short-term metabolic changes. Such studies could analyze the immediate signaling pathways and gene expression involved in the GH response. For more information, you can visit our product page for CJC-1295 + Ipamorelin.
• The combination of CJC-1295 with DAC and Ipamorelin is used in research models when a long-lasting but simultaneously enhanced GH release over several days is desired. CJC-1295 DAC ensures continuous GHRH receptor activation, while Ipamorelin, due to its shorter half-life, could be administered several times daily or via an infusion pump to amplify GH peaks. This strategy is of interest for studies on chronic tissue regeneration, improving body composition, or investigating aging processes where sustained and increased GH/IGF-1 axis stimulation is required.

For separate studies on Ipamorelin as a single peptide, our product Ipamorelin is available. The synergistic effect offers researchers a powerful tool for detailed investigation of GH secretion physiology and its diverse biological effects.

5. Analytics & Quality Control: HPLC Purity ≥98%, LC-MS Verification, Endotoxin Testing

The quality of the peptides used is of crucial importance for the reproducibility and reliability of scientific research results. At One Plus Labs, we place the highest value on comprehensive analytics and strict quality control to ensure that our research chemicals meet the highest standards.

5.1. HPLC Purity ≥98%

High-Performance Liquid Chromatography (HPLC) is one of the primary analytical methods for determining the purity of a peptide. In this technique, a peptide mixture is separated based on physicochemical properties such as polarity and molecular size. An HPLC chromatogram allows for the separation of the main component (the desired peptide) from impurities such as incomplete synthesis products, by-products, or oxidized forms, and their quantitative determination.

One Plus Labs guarantees an HPLC purity of at least ≥98% for all CJC-1295 variants. This means that less than 2% of the substance consists of compounds other than the specified peptide. High purity is crucial to ensure that observed effects in research studies are indeed attributable to the peptide under investigation and not to impurities that might possess their own biological activities.

5.2. LC-MS Verification

Liquid Chromatography-Mass Spectrometry (LC-MS) is another indispensable technique for characterizing peptides. While HPLC quantifies purity, LC-MS enables the qualitative verification of molecular mass and often the confirmation of the amino acid sequence.

• The LC component separates peptide components similar to HPLC.
• The MS component detects the mass-specific fragments of the separated components. This provides a "molecular fingerprint" that can be compared to the theoretical mass of the peptide.

Through LC-MS, One Plus Labs can confirm the correct molecular identity of each peptide and detect any modifications (such as DAC conjugation). This is a critical step to ensure the structural integrity of the peptide and to ensure product consistency across different batches.

5.3. Endotoxin Testing

Endotoxins are lipopolysaccharides (LPS) found in the outer membrane of gram-negative bacteria. Even in small amounts, they can cause strong immunogenic reactions in biological systems and falsify the results of cell-based assays or in-vivo studies. This is particularly important in peptide research, as peptide synthesis processes can be potential sources of bacterial contamination.

One Plus Labs routinely performs endotoxin testing for all injectable peptides. The concentration of endotoxins is determined using the Limulus Amebocyte Lysate assay (LAL test). We ensure that endotoxin levels are below the recognized limits for research chemicals. This minimizes the risk of non-specific inflammatory reactions and other endotoxin-induced artifacts in research results.

5.4. Ensuring Quality for Research

All these analytical steps are crucial to meet the high quality standards of One Plus Labs. For each batch of our products, we provide a CoA (Certificate of Analysis) that details the results of these tests. Full batch traceability is also guaranteed, enabling transparent and verifiable origin of the peptides. These comprehensive quality controls ensure the integrity and reproducibility of your research. Learn more about our quality standards on our Quality Standards page.

6. Storage & Stability: Lyophilized Powder, Reconstitution, Temperature Conditions

Proper storage and handling of peptides are crucial to ensure their stability, efficacy, and purity throughout the research period. Peptides are sensitive molecules that can be degraded by various factors such as temperature, light, humidity, and enzymatic activity.

6.1. Lyophilized Powder

CJC-1295 with and without DAC is typically supplied as a lyophilized (freeze-dried) powder. Lyophilization is a process in which water is sublimated from a frozen peptide solution. This results in a stable, high-purity powder that has a significantly longer shelf life than liquid solutions, as water is a key factor in peptide degradation.

• Advantages of lyophilization:
• Maximum stability: The absence of water minimizes chemical degradation reactions such as hydrolysis and oxidation.
• Long shelf life: Lyophilized peptides can remain stable for years with correct storage.
• Easy transport: Lower weight and no need for refrigeration during transport (although fast delivery times are preferred).

6.2. Reconstitution

Before use, the lyophilized peptide must be reconstituted. For the reconstitution of CJC-1295, sterile, bacteriostatic water (0.9% sodium chloride with 0.9% benzyl alcohol) is generally used in research. Benzyl alcohol acts as a preservative and inhibits the growth of bacteria in the solution.

• Recommended reconstitution process: 1. Allow the peptide vial to reach room temperature before opening to avoid condensation. 2. Carefully add the desired amount of reconstitution solvent (e.g., 1 ml per 2 mg peptide) by slowly running it down the inside wall of the vial to avoid foaming. 3. Do not shake! Shaking can destroy the delicate peptide structure. Instead, gently roll or lightly swirl the vial. 4. Allow the peptide to stand at room temperature or in the refrigerator (2-8°C) for a few minutes to hours until it has completely dissolved. Complete dissolution is crucial for accurate dosing.

6.3. Temperature Conditions and Storage

The long-term stability of lyophilized peptides is significantly improved by low temperatures.

• Storage of lyophilized powder:

• The undissolved, lyophilized peptide should ideally be stored at -20°C (freezer) or colder.

• It is stable short-term in a normal refrigerator (2-8°C), but storage at -20°C extends the shelf life to several years.

• Keep the peptide away from direct light, as light exposure can accelerate degradation.

• Storage of reconstituted solution:

• Reconstituted peptide solutions are significantly less stable than lyophilized powders.

• They should be stored in the refrigerator at 2-8°C.

• Shelf life varies greatly depending on the peptide and reconstitution solvent, but is generally between 14 and 28 days. After this time, degradation is likely.

• To maximize stability, the reconstituted solution should be divided into small aliquots and frozen (-20°C) to avoid multiple freeze-thaw cycles of the entire stock. Each freeze-thaw cycle can impair the peptide structure.

Adherence to these storage recommendations is essential to preserve the integrity of your research chemicals and to achieve valid, reproducible results in your experiments.

7. Procurement for Research Laboratories: What to look for in a supplier

Selecting the right supplier for research chemicals, especially for peptides like CJC-1295, is a critical step for any research laboratory. The quality and reliability of the supplier directly impact the credibility and reproducibility of your study results. When procuring for research laboratories, you should therefore pay attention to several key factors. For laboratory peptides, One Plus Labs offers a specialized category: Peptides for Laboratories.

7.1. Certificate of Analysis (CoA)

A CoA (Certificate of Analysis) is the most important document certifying the quality of a peptide. It should be supplied as standard with every batch and contain detailed information, including:

• HPLC purity: The percentage purity of the peptide, typically over 98%.
• LC-MS verification: Confirmation of the correct molecular mass and identity of the peptide.
• Endotoxin content: The measured endotoxin level, which for injectable research chemicals should be below certain limits.
• Production date and expiry date.
• Batch number: Enables traceability.

A reputable supplier transparently provides this information and confirms the quality of its products through independent laboratory analyses.

7.2. Batch Traceability

A system for batch traceability is essential. This means that each peptide batch sold is assigned a unique number, and the supplier is able to prove the origin, production conditions, and all quality controls performed for that specific batch. In case of unexpected results or quality problems, batch traceability allows for quick identification and investigation of the cause. One Plus Labs ensures full traceability of all shipped products.

7.3. USA Shipping and Logistics

For laboratories in Germany and the USA, US shipping is an important aspect.

• Fast delivery times: Short shipping routes within the USA minimize transit times and thus the risk of temperature fluctuations or other transport stresses that could impair peptide quality.
• Compliance with customs and import regulations: A supplier based in the USA and with US shipping practices ensures that all relevant import and customs regulations are complied with, which simplifies the procurement process and avoids delays.
• Reliable customer service: Local or USA-based customer service can provide quick and efficient support for questions or problems (e.g., regarding shipping, quality, or invoicing).

7.4. Specification of Peptide Variants

It is essential that the supplier clearly distinguishes between "CJC-1295 with DAC" and "CJC-1295 without DAC (Mod GRF 1-29)" and correctly names and describes the corresponding products. Ambiguities in product designation can lead to incorrect purchases and thus to erroneous research results. One Plus Labs ensures this on our product page for CJC-1295 DAC.

7.5. Focus on "Research Use Only"

A reputable supplier of research chemicals will always explicitly state that the products are "Research Use Only" and not intended for human consumption. This reflects the ethical and legal requirements in the field of peptide research. Such a disclaimer should be prominently displayed on the website, product labels, and documentation.

By observing these points, research laboratories can ensure that they obtain high-quality peptides from a trustworthy supplier, which forms the basis for successful and valid scientific research. Visit our Shop for our full range.

8. FAQ Section (Frequently Asked Questions)

The following questions address common concerns and search queries regarding CJC-1295 with and without DAC.

Q1: Where can I buy CJC-1295 DAC suitable for research purposes?

A1: You can purchase CJC-1295 DAC for research purposes from specialized suppliers of research chemicals such as One Plus Labs. Ensure that the supplier provides a Certificate of Analysis (CoA) confirming the purity (at least ≥98% HPLC) and identity of the peptide. Our product page for CJC-1295 DAC offers relevant information.

Q2: Are there differences when buying CJC-1295 DAC in Germany compared to other countries?

A2: In Germany and the USA, research chemicals are subject to similar regulations that permit trade exclusively for research purposes. The main difference when buying within Germany or the USA is that you benefit from fast delivery times, compliance with USA customs regulations, and more accessible customer service. One Plus Labs ships within the USA.

Q3: What is the price difference between CJC-1295 DAC and CJC-1295 without DAC (Mod GRF 1-29)?

A3: The price can vary depending on the supplier, quantity, and current market situation. Generally, CJC-1295 with DAC is often slightly more expensive to produce, as the Drug Affinity Complex (DAC) modification process requires additional synthesis steps. Costs can also be influenced by guaranteed purity and comprehensive quality controls. For specific prices, please consult our product list in the Shop.

Q4: Can I buy CJC-1295 DAC online, and what proof is required?

A4: Yes, CJC-1295 DAC can be purchased online from reputable suppliers of research chemicals. For acquisition by research laboratories, no special proof is usually required, other than confirmation that the products are intended exclusively for research purposes and not for human use. Some suppliers may require registration as a research or business customer.

Q5: What are the benefits of combining CJC-1295 with DAC and Ipamorelin in research?

A5: The combination of CJC-1295 with DAC and Ipamorelin synergizes growth hormone release. CJC-1295 DAC provides long-lasting stimulation via the GHRH receptor, while Ipamorelin, a Growth Hormone Releasing Peptide (GHRP), acts via the ghrelin receptor, enhancing release and inhibiting somatostatin action. In research models, this leads to a potentially stronger and more sustained increase in growth hormone levels, which is of interest for investigating processes such as tissue regeneration or metabolic adaptations. Further information can be found on our product page for CJC-1295 + Ipamorelin.

Q6: How do I test the purity of CJC-1295 DAC after purchase?

A6: As a research laboratory, you can verify the purity of CJC-1295 DAC and other peptides through internal or external laboratory analyses using High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography-Mass Spectrometry (LC-MS). A reputable supplier like One Plus Labs already provides a Certificate of Analysis (CoA) with each batch, which states this data and confirms purity and identity, often making additional tests unnecessary.

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⚠️ Research Use Only - Not for human consumption. The peptides presented here are exclusively for research purposes and not suitable for human use.

Scientific Sources

1. [1] "Teichman SL et al. (2006)". (). DOI:
2. [2] "Ionescu M & Bhatt DL (2006)". (). DOI:
3. [3] "Alba M et al. (2006)". (). DOI: