GRF(1-29) comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
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.
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.
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.
Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.
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.
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.
Identity and purity are established with reversed phase high performance liquid chromatography coupled to mass spectrometry. The chromatographic step separates the target peptide from truncated sequences and deletion products, while the mass measurement confirms the expected molecular weight to within a fraction of a dalton. Because the two common variants differ by the presence of the linker, mass alone can distinguish them in the unconjugated state. Amino acid analysis and peptide mapping are used when sequence level confirmation is required.
==== MeSH D06.472.910 – thymus hormones ==== MeSH D06.472.910.750 – thymic factor, circulating MeSH D06.472.910.800 – thymopoietins MeSH D06.472.910.800.850 – thymopentin MeSH D06.472.910.850 – thymosin
== Side effects == Calcium gluconate side effects include nausea, constipation, and upset stomach. Rapid intravenous injections of calcium gluconate may cause hypercalcemia, which can result in vasodilation, cardiac arrhythmias, decreased blood pressure, and bradycardia. Extravasation of calcium gluconate can lead to cellulitis. Intramuscular injections may lead to local necrosis and abscess formation. It is also reported that this form of calcium increases renal plasma flow, urine production, sodium excretion, glomerular filtration rate, and prostaglandin E2 and F1-alpha levels.
== Histology == The sulcular epithelium is a stratified squamous, non-keratinized epithelium that lines the gingival sulcus and extends from the coronal edge of the junctional epithelium to the free gingival margin.
=== Formation of four bonds === This is a general method that is able to give good yields for substituted imidazoles. In essence, it is an adaptation of the Debus method called the Debus-Radziszewski imidazole synthesis. The starting materials are substituted glyoxal, aldehyde, amine, and ammonia or an ammonium salt.
== See also == Aptamers, oligonucleotides with important biological applications Morpholinos, oligos with non-natural backbones, which do not activate RNase-H but can reduce gene expression or modify RNA splicing Polymorphism, the appearance in a population of the same gene in multiple forms because of mutations; can often be tested with ASO probes CpG Oligodeoxynucleotide, an ODN with immunostimulatory properties Polypurine reverse-Hoogsteen hairpins, PPRHs, oligonucleotides that can bind either DNA or RNA and decrease gene expression.
Sources: en.wikipedia.org
Cyclopropanones- three-membered ring ketones- are also hydrated to a significant extent. Since three-membered rings are very strained (bond angles forced to be 60˚), sp3 hybridization is more favorable than sp2 hybridization. For the sp3 hybridized hydrate the bonds have to be distorted by about 49˚, while for the sp2 hybridized ketone the bond angle distortion is about 60˚. So the addition to the carbonyl group allows some of the strain inherent in the small ring to be released, which is why cyclopropanone and cyclobutanone are very reactive electrophiles. For larger rings, where the bond angles are not as distorted, the stability of the hemiacetals is due to entropy and the proximity of the nucleophile to the carbonyl group. Formation of an acyclic acetal involves a decrease in entropy because two molecules are consumed for every one produced. In contrast, the formation of cyclic hemiacetals involves a single molecule reacting with itself, making the reaction more favorable. Another way to understand the stability of cyclic hemiacetals is to look at the equilibrium constant as the ratio of the forward and backward reaction rate. For a cyclic hemiacetal the reaction is intramolecular so the nucleophile is always held close to the carbonyl group ready to attack, so the forward rate of reaction is much higher than the backward rate. Many biologically relevant sugars, such as glucose, are cyclic hemiacetals.
{\displaystyle {\begin{aligned}\rho (x,y,z)&={\frac {3B}{r^{2}+x^{2}+y^{2}+z^{2}}}\\p(x,y,z)&={\frac {-A^{2}B}{\left(r^{2}+x^{2}+y^{2}+z^{2}\right)^{3}}}\\\mathbf {u} (x,y,z)&={\frac {A}{\left(r^{2}+x^{2}+y^{2}+z^{2}\right)^{2}}}{\begin{pmatrix}2(-ry+xz)\\2(rx+yz)\\r^{2}-x^{2}-y^{2}+z^{2}\end{pmatrix}}\\g&=0\\\mu &=0\end{aligned}}}
Slovakia: Prime Minister Robert Fico criticized the actions of the United States, stating that "International law does not apply, military power is used without the mandate of the UN Security Council, and everyone who is great and strong does what he wants to promote their own interests," and that "I resolutely reject such a disruption of international law, as I did in the Iraq war, in the denial of Kosovo as a sovereign state, or in the use of Russian military power in Ukraine." He also suggested that the European Union should apply the same standards that were used with Russia when it invaded Ukraine, saying that "Either the use of American military force in Venezuela will be condemned and be consistent with attitudes to the war in Ukraine, or, as usual, remain pharisaical." Spain: The Foreign Ministry called for "de-escalation and moderation", and for compliance with "international law and the principles of the UN charter" adding that the ministry was "prepared to offer its good offices to achieve a peaceful and negotiated solution". They reiterated that they did not recognize the results of the 2024 Venezuelan presidential election and that Spain "has welcomed, and will continue to welcome, tens of thousands of Venezuelans who have had to leave their country for political reasons." On 4 January 2026, Brazil, Spain, Chile, Colombia, Mexico, and Uruguay issued a joint statement to express their "profound concern and firm rejection of the military actions carried out unilaterally in Venezuelan territory" by the United States.
This stage was marked by increased violence as different cartels fought for control of export markets. Despite this strife, this power struggle led to then having multiple producers of coca leaf farms. This in turn caused an improvement in quality control and reduction of police interdiction in the distribution of cocaine. This also led to cartels attempting to repatriate their earnings which would eventually make up 5.5% of Colombia's GDP. This drive to repatriate earnings led to the pressure of legitimizing their wealth, causing an increase in violence throughout Colombia.
== Analysis == A wide range of instrumental techniques are employed in nuclear forensics. Radiometric counting techniques are useful when determining decay products of species with short half-lives. However, for longer half-lives, inorganic mass spec is a powerful means of carrying out elemental analysis and determining isotopic relationships. Microscopy approaches can also be useful in characterization of a nuclear material.
Sources: en.wikipedia.org
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.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
Mass spectrometry establishes whether the observed molecular weight matches the calculated sequence mass. Chromatographic retention and fragment mapping add further confidence about sequence and composition. A single technique alone is rarely treated as sufficient evidence of identity.