cjc-1295 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-04-23. Numbers and descriptions here follow the published literature rather than marketing material.
The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.
Studies in this area generally track growth hormone pulses, insulin-like growth factor 1 concentrations, and occasionally body composition endpoints. Most published human data come from early, small trials, and questions about long-term effects remain open. Whether repeated exposure alters pituitary responsiveness over time is not settled. Analytical work relies on immunoassays for the hormones and on mass spectrometry for the peptide itself, because the two measurements answer different questions.
Binding of the peptide to the growth hormone-releasing hormone receptor on pituitary somatotrophs triggers a G protein coupled cascade that raises cyclic AMP and opens calcium channels. The result is greater secretion of growth hormone into the bloodstream. Because the peptide acts at the same receptor as the natural hypothalamic hormone, its effect is amplified pulse size rather than an entirely separate release pathway. Receptor binding alone does not determine the response, since somatostatin tone and other inputs modulate the final output.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Target receptor | GHRH receptor (GHRHR) | Expressed on pituitary somatotrophs |
| Primary action | Stimulates growth hormone release | Amplifies pulse size |
| Half-life, albumin-binding form | Several days as reported | Slow release from albumin complex |
| Half-life, unmodified analog | About 30 minutes in animal estimates | Cleared by proteases and filtration |
| Common analytical approach | LC-MS/MS for peptide, immunoassay for hormones | Methods answer different questions |
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
A link between the sympathetic nervous system and the lungs was shown in 1887 when Grossman showed that stimulation of cardiac accelerator nerves reversed muscarine-induced airway constriction. In experiments in the dog, where the sympathetic chain was cut at the level of the diaphragm, Jackson showed that there was no direct sympathetic innervation to the lung, but bronchoconstriction was reversed by the release of adrenaline from the adrenal medulla. An increased incidence of asthma has not been reported for adrenalectomized patients; those with a predisposition to asthma will have some protection from airway hyper-reactivity from their corticosteroid replacement therapy. Exercise induces progressive airway dilation in normal subjects that correlates with workload and is not prevented by beta-blockade. The progressive airway dilation with increasing exercise is mediated by a progressive reduction in resting vagal tone. Beta blockade with propranolol causes a rebound in airway resistance after exercise in normal subjects over the same time course as the bronchoconstriction seen with exercise-induced asthma. The reduction in airway resistance during exercise reduces the work of breathing.
hit identification using virtual screening (structure- or ligand-based design) hit-to-lead optimization of affinity and selectivity (structure-based design, QSAR, etc.) lead optimization of other pharmaceutical properties while maintaining affinity
==== Cofactors ==== Protein enzymes catalyze various chemical reactions, but over half of them incorporate cofactors to facilitate and diversify their catalytic activities. Cofactors are essential in biology, as they are based largely on nucleotides rather than amino acids. Ribozymes use nucleotide cofactors to create metabolism, with two basic choices: non-covalent binding or covalent attachment. Both approaches have been demonstrated using directed evolution to reinvent RNA dupes of protein-catalyzed processes. Lorsch and Szostak investigated ribozymes that could phosphorylate themselves and use ATP-γS as a substrate. However, only one of the seven classes of selected ribozymes had detectable ATP affinity, indicating that the ability to bind ATP was compromised. NAD+- dependent redox ribozymes were also evaluated. The selected ribozyme had a rate of enhancement of more than 107 fold and was proven to catalyze the reverse reaction - benzaldehyde reduction by NADH. Since the usage of adenosine as a cofactor is prevalent in current metabolism and is likely to have been common in the RNA world, these discoveries are essential for the evolution of metabolism in the RNA world.
Sources: en.wikipedia.org
=== Vacation food === Vacation foods, also known as "food blocks" (or "weekend blocks" for smaller versions), are designed to be placed inside the aquarium to forgo feeding while the owner is absent. These blocks release small amounts of food as they dissolve. Food blocks can be a good choice for smaller tropical fish, but can pollute the water if the tank is neglected for too long.
== Enzyme activity == In many of the species containing lactate racemase, the physiological role of the enzyme is to convert substrate D-lactate into L-lactate. In other species, such as L. plantarum, the cellular role is to transform L-lactate into D-lactate for incorporation into the cell wall. The in vitro reaction catalyzed by the enzyme reaches equilibrium at the point where approximately equimolar concentrations of the D- and L-isomers exist. L. plantarum initially produces L-lactate, which induces the activity of lactate racemase. By contrast, D-lactate represses lactate racemase activity in this species. Therefore, Lar activity appears to be regulated by the ratio of L-lactate/D-lactate. L. plantarum LarA represents a new type of nickel-dependent enzyme, due to its novel nickel-pincer ligand ligand cofactor.
=== In LTP === When alpha-CaMKII is knocked out in mice, LTP is reduced by 50%. This can be explained by the fact that beta-CaMKII is responsible for approximately 65% of CaMKII activity. LTP can be completely blocked if CaMKII is modified so that it cannot remain active. After LTP induction, CaMKII moves to the postsynaptic density (PSD). However, if the stimulation does not induce LTP, the translocation is quickly reversible. Binding to the PSD changes CaMKII so that it is less likely to become dephosphorylated. CaMKII transforms from a substrate for Protein Phosphatase 2A (PP2A), which is responsible for dephosphorylating CaMKII, to that of Protein Phosphatase 1. Strack, S. (1997) demonstrated this phenomenon by chemically stimulating hippocampal slices. This experiment illustrates that CaMKII contributes to the enhancement of synaptic strength. Sanhueza et al. found that persistent activation of CaMKII is necessary for the maintenance of LTP. She induced LTP in hippocampal slices and experimentally applied an antagonist (CaMKIINtide) to prevent CaMKII from remaining active. The slices that were applied with CaMKIINtide showed a decrease in Normalized EPSP slope after the drug infusion, meaning that the induced LTP reversed itself. The Normalized EPSP slope remained constant in the control; CaMKII continues to be involved in the LTP maintenance process even after LTP establishment. CaMKII is activated by calcium/calmodulin, but it is maintained by autophosphorylation. CaMKII is activated by the NMDA-receptor-mediated Calcium elevation that occurs during LTP induction.
Sources: en.wikipedia.org
==== Quantum dot with nanowire in solar cells ==== Another potential use involves capped single-crystal ZnO nanowires with CdSe quantum dots, immersed in mercaptopropionic acid as hole transport medium in order to obtain a QD-sensitized solar cell. The morphology of the nanowires allowed the electrons to have a direct pathway to the photoanode. This form of solar cell exhibits 50–60% internal quantum efficiencies. Nanowires with quantum dot coatings on silicon nanowires (SiNW) and carbon quantum dots. The use of SiNWs instead of planar silicon enhances the antiflection properties of Si. The SiNW exhibits a light-trapping effect due to light trapping in the SiNW. This use of SiNWs in conjunction with carbon quantum dots resulted in a solar cell that reached 9.10% PCE. Graphene quantum dots have also been blended with organic electronic materials to improve efficiency and lower cost in photovoltaic devices and organic light emitting diodes (OLEDs) compared to graphene sheets. These graphene quantum dots were functionalized with organic ligands that experience photoluminescence from UV–visible absorption.
== Analysis == Quincy Institute's political scientist Annelle Sheline has argued that Trump's plan for Gaza would not only constitute ethnic cleansing, but would also destabilize the Middle East, since the displacement of Palestinians into Jordan would provoke a period of social upheaval that could topple the Jordanian monarchy and create an entirely new state in the region. She argued that if such an event were to take place, the Jordanian Muslim Brotherhood could seize control of the country. This view has been supported by Paul Piller (fellow at the Quincy Institute) who argued that the displacement of Palestinians into Jordan would effectively end the Jordanian-Israeli peace agreement of 1994 and risk the overthrow of the Jordanian monarchy. Oraib Rantawi, head of the Amman Al Quds Center for Political Studies, said the plan would affect Jordan's demography, identity, and security. Egyptian officials warned that the inflow of hundreds of thousands of Hamas militants into the Sinai border resulting from the plan would destabilize the region and put Egypt's peace agreement with Israel in jeopardy. Also at the Quincy Institute, Rabwan Ahari has argued that Trump's proposal signals a clear and substantial departure from America having "even the pretense of supporting a two-state solution." They further argued that this plan amounted to a statement that Palestinian displacement was the goal of US policy surrounding the region.
=== Pneumococcal vaccine === From 1971 to 1985, Ammann was director of Pediatric Immunology and Clinical Research Center at UCSF. It was during this period that Ammann performed a series of clinical trials aimed at protecting children with sickle cell anemia and the elderly from pneumococcal infection, a bacterium that causes fatal infection. He and his colleagues were successful in creating the first U.S. Food and Drug Administration-approved vaccine effective against the bacteria; it granted individuals immunity against a life-threatening infection. Ammann's vaccine has since been expanded and its immunogenicity has been improved, increasing the effectiveness of the vaccine in young infants. This discovery has saved the lives of millions of individuals by preventing pneumococcal infection, particularly in children and the elderly.
Sources: en.wikipedia.org
Reported values cluster in the range of several days, reflecting slow release from the albumin complex. Estimates differ across species and assay platforms. The figure describes circulation time in study settings rather than a fixed property.
Typical endpoints include growth hormone pulse frequency and amplitude, together with insulin-like growth factor 1 concentration. Some protocols add body composition or metabolic markers. Interpretation depends on baseline hormonal status, which varies widely between individuals.
Most human data come from small, early-stage studies, and independent replication is limited. Short-term effects on growth hormone release are documented; longer-term outcomes are not well characterized. Open questions include changes in pituitary responsiveness after repeated exposure.
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.