Everything below concerns Lyophilized powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
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.
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.
| 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 |
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
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.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
Navigator History of Pharmacy Collection of internet resources related to the history of pharmacy Soderlund Pharmacy Museum Archived 18 July 2019 at the Wayback Machine – Information about the history of the American Drugstore The Lloyd Library Library of botanical, medical, pharmaceutical, and scientific books and periodicals, and works of allied sciences American Institute of the History of Pharmacy American Institute of the History of Pharmacy—resources in the history of pharmacy International Pharmaceutical Federation (FIP) Federation representing national associations of pharmacists and pharmaceutical scientists. Information and resources relating to pharmacy education, practice, science and policy
=== Investigators === Investigators are often compensated for their work in clinical trials. These amounts can be small, just covering a partial salary for research assistants and the cost of any supplies (usually the case with national health agency studies), or be substantial and include "overhead" that allows the investigator to pay the research staff during times between clinical trials.
== Mechanism == Opioid analgesic drugs tend to exhibit incomplete cross-tolerance, so that even when a patient has developed a high level of tolerance to one drug from this class, they may find that a different opioid drug will still be effective. The reasons for this are still not completely understood, but are thought to result from variations in opioid receptor affinity and occupancy levels at equianalgesic doses, as well as additional mechanisms of action possessed by some drugs such as the NMDA antagonist action of methadone or levorphanol, or the SNRI activity of tramadol or tapentadol.
=== Mixed series === The use of the different vaccines in a two-shot regimen is not widespread; there is no data on the efficacy of mixed series for COVID-19 vaccines but such series are not expected to be unsafe or ineffective. The US Centers for Disease Control and Prevention (CDC) recommends the use of a mixed series only in exceptional circumstances, such as where a second dose of the same vaccine cannot be delivered in a reasonable timeframe. In Canada, authorities were investigating the effectiveness of a mixed series and ultimately recommended the use of a first shot consisting of the Oxford-AstraZeneca COVID-19 vaccine, followed by one of the mRNA vaccines. In June 2021, German authorities recommended using mRNA vaccines as a second shot after an AstraZeneca shot in younger people as a precaution to avoid a rare blood clotting side effect associated with the AstraZeneca vaccine. Thailand began mixing-and-matching doses of the AstraZeneca and Sinovac vaccines in July 2021 amid concerns about the Sinovac vaccine's long-term protection.
Sources: en.wikipedia.org
== Further reading == Castka, Joseph F.; Metcalfe, H. Clark; Davis, Raymond E.; Williams, John E. (2002). Modern Chemistry. Holt, Rinehart and Winston. ISBN 978-0-03-056537-3. Guch, Ian (2003). The Complete Idiot's Guide to Chemistry. Alpha, Penguin Group Inc. ISBN 978-1-59257-101-7. Mascetta, Joseph A. (1998). How to Prepare for the SAT II Chemistry. Barron's. ISBN 978-0-7641-0331-5.
When the Basilica of Saint-Denis was desecrated by French revolutionaries in 1793, the body of Henry IV was so well preserved it was displayed two days before being thrown in a mass grave, and a new death mask was able to be made. Likewise, Louis XIII was still recognisable thanks to his well preserved moustache. Turenne was so well preserved that looters first thought he was still alive. Maria II of Portugal died in childbirth on 15 November 1853, at the age of 34. Her embalming was conducted the following day and proved to be a complex procedure due to the rapid post-mortem changes in her remains. The Duchess of Ficalho, the queen's lady-in-waiting, provided a primary account of the event in a letter to her brother, the 2nd Count of Lavradio: The sad embalming took place on November 16th, and I was present throughout. The procedure for the Infante and the Queen lasted seven hours. Once that ordeal was over, it was time to dress the body, which was nearly impossible due to the state of dissolution of Her Majesty. Nevertheless, it was done as well as possible, including the placement of the Orders and the Royal Mantle. It was ultimately necessary to close the coffin, for the state of dissolution was beyond description. In 2012, an exhumation of the remains of Amélie of Leuchtenberg (1812–1873), Empress of Brazil, revealed that her body had undergone extensive long-term preservation. Despite being interred for 139 years, the body was found mummified with skin, hair, and internal organs intact.
== History == The first YTX analog discovered, yessotoxin, was initially found in the scallop species Patinopecten yessoensis in the 1960s. Since then, numerous yessotoxin analogs have been isolated from shellfish and marine algae (including 45-hydroxyyessotoxin and carboxyyessotoxin). Initially, scientists wrongly classified YTXs in the group of diarrhetic shellfish poisoning (DSP) toxins along the lines of okadaic acid and azaspiracids. These types of toxins can cause extreme gastrointestinal upset and accelerate cancer growth. Once scientists realized YTXs did not have the same toxicological mechanism of action as the other toxins (protein phosphatase inhibitors), they were given their own classification.
Sources: en.wikipedia.org
cadherin Any of a class of transmembrane proteins which are dependent on calcium ions (Ca2+) and whose extracellular domains function as mediators of cell–cell adhesion at adherens junctions in eukaryotic tissues.
== Properties == LCRs are more abundant in eukaryotes, but they also have a significant presence in many prokaryotes. On average, 0.05 and 0.07% of the bacterial and archaeal proteomes (total amino acids of LCRs in a given proteome/total amino acids of that proteome) form LCRs whereas for five model eukaryotic proteomes (human, fruitfly, yeast, fission yeast, Arabidopsis) this coverage was significantly higher (on average, 0.4%; between 2 and 23 times higher than prokaryotes). Eukaryotic LCRs tend to be longer than prokaryotic LCRs. The average size of a eukaryotic LCR is 42 amino acids long, whereas bacterial, archaeal and phage LCRs are 38, 36 and 33 amino acids long, respectively. In the Archaea, the halobacterium Natrialba magadii has the highest number of LCRs and the highest enrichment for LCRs. In Bacteria, Enhygromyxa salina, a delta proteobacterium that belongs to myxobacteria has the highest number of LCRs and the highest enrichment for LCRs. Intriguingly, four of the top five bacteria with the highest enrichment for LCRs are also myxobacteria. The three most enriched amino acids within LCRs of Bacteria are proline, glycine and alanine, whereas in Archaea they are threonine, aspartate and proline. In Phages, they are alanine, glycine and proline. Glycine and proline emerge as very enriched amino acids in all three evolutionary lineages, whereas alanine is highly enriched in Bacteria and Phages but not enriched in Archaea.
{\displaystyle {\begin{aligned}\Delta p={\frac {1}{2}}\rho {\overline {v}}_{\text{max}}^{2}&={\frac {1}{2}}\rho \left({\frac {Q_{\text{max}}}{\pi R^{2}}}\right)^{2}\\\Rightarrow \quad Q_{\max }{}&=\pi R^{2}{\sqrt {\frac {2\Delta p}{\rho }}},\end{aligned}}}
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.
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.