Description

Technical Parameters

Introduction

peptides

product-1400-1400

Products Description

#### **1. Overview of CJC-1295 without DAC**

**CJC-1295 without DAC** (also known as **Modified GRF 1-29**) is a synthetic growth hormone-releasing hormone (GHRH) analogue, consisting of 29 amino acids, which modifies the structure of natural GHRH (1-44) to enhance its stability and biological activity. Unlike the version containing DAC (Drug Affinity Complex), CJC-1295 without DAC does not have a chemical group (DAC) that binds to albumin, so its half-life is shorter (about 30 minutes to 2 hours), and more frequent injections are required to maintain the effect.

#### **2. Classification and characteristics of CJC-1295 without DAC**

Based on its functions, applications and physicochemical properties, CJC-1295 without DAC can be divided into the following categories:

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##### **1. Pharmacological properties**

- **Mechanism of action**:

CJC-1295 stimulates the secretion of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) by activating the GHRH receptors in the anterior pituitary. Its action depends on pulsed release, simulating the physiological rhythm of natural GHRH.

- **Pharmacokinetics**:

Because it does not contain DAC, its half-life is short (about 0.5-2 hours), and multiple injections (usually 1-3 times) are required daily to maintain GH pulses. The blood clearance rate is fast, and metabolism is mainly completed by the kidneys and liver.

- **Receptor selectivity**:

It has high affinity for GHRH receptors (Ki value of about 1-3 nM), and almost no binding to irrelevant receptors (such as vasoactive intestinal peptide receptors), with strong specificity.

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##### **2. Physical and chemical properties**

- **Molecular weight and structure**:

The molecular weight is 3367.9 Da, and the sequence is **H-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-NH₂**. Its core modification includes replacing L-alanine at position 2 with D-alanine to resist protease degradation.

- **Solubility**:

Easily soluble in water (optimal solubility at pH 4-7), can form a transparent solution in physiological saline and sterile water for injection. Slight turbidity may occur at high concentrations, but it does not affect activity.

- **Stability**:

It can be stored for a long time in a lyophilized state (more than 2 years at -20°C), and the solution state needs to be refrigerated (2-8°C) and used within 7 days. It is sensitive to high temperatures (>40°C causes denaturation), avoid light and repeated freezing and thawing.

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##### **3. Color and morphology**

- **Appearance**:

The pure product is a white or off-white lyophilized powder with a loose texture. If it contains impurities (such as side chain protecting groups remaining during the synthesis process), it may appear slightly yellow, but the activity is usually not affected.

- **Solution color**:

After reconstitution, it is a colorless and transparent liquid. If turbidity or precipitation occurs, it may be denatured due to contamination or improper storage.

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##### **4. Clinical application and advantages**

- **Indications**:

- Replacement therapy for growth hormone deficiency (GHD)

- Muscle atrophy and exercise recovery (promoting protein synthesis through IGF-1)

- Anti-aging and tissue repair (stimulating collagen production)

- Metabolic syndrome (improving fat oxidation and insulin sensitivity)

- **Advantages**:

- **High safety**: Short half-life reduces the risk of excessive GH secretion (such as joint pain, edema).

- **Pulse release**: Closer to the physiological GH secretion pattern, avoiding negative feedback inhibition of IGF-1.

- **Low immunogenicity**: Modified structure reduces the risk of antibody generation, and long-term use is well tolerated.

- **Flexible dosing**: The dose and frequency can be adjusted according to individual needs.

- **Limitations**:

- Frequent injections are required (low compliance)

- Single-shot effects are short-lived (long-term use is required)

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##### **5. Synthesis and quality control**

- **Synthesis method**:

Solid phase peptide synthesis (SPPS) is used to gradually connect amino acids using Fmoc chemistry. Key steps include:

- Stereoselective introduction of D-alanine

- C-terminal amidation for enhanced stability

- HPLC purification (purity>98%)

- **Quality control indicators**:

- Purity: HPLC detection ≥95%

- Residual solvents: ether, ethyl acetate, etc. must be lower than the pharmacopoeia standard

- Endotoxin: <0.1 EU/mg (injection grade requirements)

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##### **6. Experimental studies and clinical data**

- **Animal experiments**:

In rat models, a single injection of CJC-1295 without DAC (100 μg/kg) can increase GH levels by 5-8 times for 1-2 hours.

- **Human trials**:

- **Healthy subjects**: Twice daily injections (1 mg/time) for 7 consecutive days increased IGF-1 levels by 60%-80%.

- **Elderly population**: A 6-month study showed that subjects increased lean body mass by 4% and decreased fat mass by 7%.

#### **3. Comparison with other growth hormone releasing peptides**

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#### **4. Future research directions**

1. **Long-term improvement**: Explore non-DAC-dependent sustained-release technologies (such as nanocarriers).

2. **Combination therapy**: Combined with GHRP-6 or insulin-like growth factor to enhance the effect.

3. **Oral formulation development**: Improve bioavailability through liposomes or penetration enhancers.

#### **5. Summary**

CJC-1295 without DAC occupies a unique position in the field of precise regulation of GH secretion due to its short-term and high safety characteristics. Although the need for frequent injections limits some application scenarios, its potential in anti-aging, sports medicine and metabolic diseases is still worth exploring in depth. In the future, through technological innovation and clinical verification, its application boundaries may be further broadened.