The short version of mass spectrometry fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-06. Anything still debated is marked as such rather than presented as settled.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
To avoid the complications involved in using activities, stability constants are determined, where possible, in a medium consisting of a solution of a background electrolyte at high ionic strength, that is, under conditions in which
=== In pharmacology === Bioavailability is a term used to describe the percentage of an administered dose of a xenobiotic that reaches the systemic circulation unchanged. It is denoted by the letter f (or, if expressed in percent, by F).
==== VAT systems ==== In Europe, Value-Added Tax (VAT) rates vary among member states, with a standard rate that cannot be less than 15%. Countries like Hungary, Croatia, Denmark, and Sweden have higher standard VAT rates, while Luxembourg, Malta, Cyprus, Greece, Germany, and Romania have lower rates. In China, wholesalers were subject to a Value-Added Tax (VAT) of either 9% or 13% on imported goods, depending on the type of product. Additionally, consumption tax is levied on products such as tobacco, alcohol, and luxury goods. These taxes are part of China's broader strategy to promote domestic consumption and regulate imports. A recent set of summaries of China's VAT law changes describes a maintained multi-rate VAT structure, including 13% for many goods sales/imports and other rates for specific categories. On the other hand, Vietnam imposed a standard VAT rate of 10% on most goods and services, with exemptions for certain agricultural products and essential services. In recent years, Vietnam has used a temporary VAT reduction policy with an extension of an 8% rate for many goods and services (with notable exclusions) through the end of 2026.
Sources: en.wikipedia.org
amination (see Figure) The C-terminus can also be blocked (thus, neutralizing its negative charge) by amination. glycosyl phosphatidylinositol (GPI) attachment Glycosyl phosphatidylinositol(GPI) is a large, hydrophobic phospholipid prosthetic group that anchors proteins to cellular membranes. It is attached to the polypeptide C-terminus through an amide linkage that then connects to ethanolamine, thence to sundry sugars and finally to the phosphatidylinositol lipid moiety. Finally, the peptide side chains can also be modified covalently, e.g.,
Past or current history of substance abuse Undiagnosed psychiatric disorders, yet to be identified and treated A young age Family history of substance abuse Social environments that encourage substance use Prolonged use or treatment with opioids Statistically, middle-aged patients with substance use history and psychiatric comorbidities are seen with higher mortality risks such as suicide. Iatrogenic physiological and psychological drug dependence can occur to one of any background. Some physicians are more liberal with their prescribing of opiates and their patients become dependent on opiates by simply following their doctor's orders.
Bisoprolol, sold under the brand name Zebeta among others, is a beta blocker which is selective for the beta-1 receptor and used for cardiovascular diseases, including tachyarrhythmias, high blood pressure, angina, and heart failure. It is taken by mouth. Common side effects include headache, feeling tired, diarrhea, and swelling in the legs. More severe side effects include worsening asthma, blocking the ability to recognize low blood sugar, and worsening heart failure. There are concerns that use during pregnancy may be harmful to the fetus. Bisoprolol was patented in 1976 and approved for medical use in 1986. It was approved for medical use in the United States in 1992. Bisoprolol is on the World Health Organization's List of Essential Medicines and is available as a generic medication. In 2023, it was the 221st most commonly prescribed medication in the United States, with more than 1 million prescriptions.
Promising results of health and medical research are reported: phase 3-trialed R21/Matrix-M vaccine against Malaria (1 Feb), phase 3-trialed resmetirom as first medication against nonalcoholic steatohepatitis of the liver (7 Feb), a blood test against heart attacks, the top cause of human deaths (12 Feb), a low-cost saliva test against breast cancer (13 Feb), pigs-tested patient repositioning method for magnetic microbot navigation against liver cancer (14 Feb), antibiotic cresomycin against multiple drug-resistant bacterial strains (15 Feb), small-trialed 15 min exposure to 670 nm red light against blood glucose spikes following meals (20 Feb), small-trialed Omalizumab against food allergies (25 Feb), a donor heart is transplanted after 12 hours of preservation and transport using an airplane, small-trialed headgear for gamma stimulation to recruit the glymphatic system to remove brain amyloid against Alzheimer's disease (28 Feb).
Sources: en.wikipedia.org
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.