This is a working overview of GRF(1-29), written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
Reconstitution is typically performed with sterile water or bacteriostatic water, added slowly against the vial wall. The resulting solution should be clear and colorless; cloudiness or visible particles suggest a problem with the material or the diluent. Once in solution, the peptide is less stable than the dry powder. Refrigerated storage at two to eight degrees Celsius is common for short-term holding, while freezing aliquots is described for longer periods.
Purity is most often assessed by reversed-phase high-performance liquid chromatography, reported as a percentage of total peak area. Identity is confirmed by mass spectrometry, which yields a molecular ion consistent with the expected sequence. Amino acid analysis and peptide mapping provide additional characterization. Reported purity values are method-dependent, so figures from different laboratories are not always directly comparable without details of column, gradient, and detection wavelength.
| 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.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
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Sources: en.wikipedia.org
A biological half-life or elimination half-life is the time it takes for a substance (drug, radioactive nuclide, or other) to lose one-half of its pharmacologic, physiologic, or radiological activity. In a medical context, the half-life may also describe the time that it takes for the concentration of a substance in blood plasma to reach one-half of its steady-state value (the "plasma half-life"). The relationship between the biological and plasma half-lives of a substance can be complex, due to factors including accumulation in tissues, active metabolites, and receptor interactions. While a radioactive isotope decays almost perfectly according to first order kinetics, where the rate constant is a fixed number, the elimination of a substance from a living organism usually follows more complex chemical kinetics. For example, the biological half-life of water in a human being is about 9 to 10 days, though this can be altered by behavior and other conditions. The biological half-life of caesium in human beings is between one and four months. The concept of a half-life has also been utilized for pesticides in plants, and certain authors maintain that pesticide risk and impact assessment models rely on and are sensitive to information describing dissipation from plants. In epidemiology, the concept of half-life can refer to the length of time for the number of incident cases in a disease outbreak to drop by half, particularly if the dynamics of the outbreak can be modeled exponentially.
== Partitioning and transmutation strategy == Many efforts are being devoted to develop an advanced reprocessing approach with the aim to further reduce the radiotoxicity inventory of the spent nuclear fuel by removing all minor actinides (Neptunium, Americium and Curium) and the long-lived fission products (LLFP) from the high active raffinate downstream of the PUREX process. Before the conditioning process, the long-lived radionuclides undergo a transmutation into short-lived or stable nuclides by nuclear reactions. This coupled approach is known as Partitioning and Transmutation strategy (P&T), which inclusion in an advanced closed fuel cycle could lead to strongly reduce long-term radiotoxicity, volume and decay heat of the final waste thus simplifying a performance assessment of a future nuclear waste repository and enhancing proliferation resistance criteria. Two potential process options for the partitioning of spent nuclear fuel are being developed: hydrometallurgical and pyrometallurgical processes. The hydrometallurgical partitioning, also known as solvent extraction process, was born and developed in Europe thereby becoming the reference technology for future SNF reprocessing at industrial level, whereas the pyrometallurgical option started in the United States and Russia as an alternative to the aqueous processes.
==== Toronto City Council ==== The Ford government passed the Better Local Government Act into law on August 14, 2018. Premier Ford announced the controversial bill on September 27, on the last day for candidate registration for the October 22, 2018 Toronto municipal election, newly elected Premier of Ontario Doug Ford introduced the Better Local Government Act (Bill 5) which requires that Toronto use the same ridings for all its elections—municipal, provincial, and federal—effectively reducing the Toronto City Council from 47 seats to 25. Bill 5 passed on August 14, 2018. Toronto is Ontario's capital city and the largest city in Canada with a population of 2.7 million. The number of Council seats had just been expanded following approximately four years of consultations and debates. Ford said that these reductions would lower the cost to taxpayers by $CDN 25 ($USD19.1) million dollars in Toronto's $CDN11.1 ($USD8.5) billion dollar budget. Bill 5 reset the positions of regional municipality chairs as by appointment not be election in Peel, York, Niagara and Muskoka.
The study has enrolled over 20,000 newborns and expanded its panel to include 446 genes associated with more than 460 actionable conditions. The GUARDIAN study was recognized by JAMA as Research of the Year for 2025. Additionally, GeneDx is a partner in Florida's Sunshine Genetics Program, the first state-supported initiative to integrate genomic sequencing into newborn screening.
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.
Cool, dark, and dry conditions are standard, with storage at minus twenty degrees Celsius or below. Desiccant and sealed vials limit moisture uptake. Repeated warming and cooling of the container is generally avoided.