Mod GRF(1-29) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
Reports on this compound commonly follow serum growth hormone and insulin-like growth factor 1 across defined time windows. Protocols differ in sampling frequency, assay platform, and participant characteristics, which makes direct comparison between publications difficult. Some work focuses on pulsatile release patterns instead of average concentrations. Whether repeated exposure alters endogenous hormone rhythms over long periods remains an open question, and the formal literature is thinner than the volume of informal commentary implies.
Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.
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.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.
Analytical confirmation usually relies on reversed-phase high-performance liquid chromatography for purity and on liquid chromatography coupled to mass spectrometry for identity. Mass data reveal the expected molecular mass and can flag truncated or oxidized species. Amino acid analysis and peptide mapping provide sequence-level verification. Immunoassays are used in some biological matrices, but antibodies raised against one releasing-hormone analog may cross-react with another. Reported purity figures depend heavily on the method used, so comparisons between suppliers require matching the analytical approach.
Studies on the effect of drugs on trypanothione metabolism resulted in the discovery that fexinidazole is a potential oral treatment for visceral leishmaniasis. In 2006 Fairlamb and Mike Ferguson became co-directors of the Drug Discovery Unit at the University of Dundee. The new centre, opened in 2005, has facilities for high-throughput screening and medicinal chemistry. These will take the drug discovery/development process further than any other UK university, to a stage where pharmaceutical companies will have sufficient data to move into the production stage.
AGIF Adipogenesis inhibitory factor Interleukin-11 precursor. Oprelvekin is produced in Escherichia coli (E. coli) by recombinant DNA technology. The protein has a molecular mass of approximately 19,000 g/mol, and is non-glycosylated. The polypeptide is 177 amino acids in length (the natural IL-11 has 178). This alteration has not resulted in measurable differences in bioactivity either in vitro or in vivo. The primary hematopoietic activity of Neumega is stimulation of megakaryocytopoiesis and thrombopoiesis. In mice and nonhuman primate studies Neumega has shown potent thrombopoietic activity in compromised hematopoiesis, including moderately to severely myelosuppressed animals. In these studies, Neumega improved platelet nadirs and accelerated platelet recoveries compared to controls. In animal studies oprelvekin also has non-hematopoietic activities. This includes the regulation of intestinal epithelium growth (enhanced healing of gastrointestinal lesions), the inhibition of adipogenesis, the induction of acute phase protein synthesis (e.g., fibrinogen), and inhibition of macrophageal released pro-inflammatory cytokines. However, pathologic changes, some also seen in humans, have been noticed:
=== The molecular clock and the units of time === Typically, a branch length of a phylogenetic tree is expressed as the expected number of substitutions per site; if the evolutionary model indicates that each site within an ancestral sequence will typically experience x substitutions by the time it evolves to a particular descendant's sequence then the ancestor and descendant are considered to be separated by branch length x. Sometimes a branch length is measured in terms of geological years. For example, a fossil record may make it possible to determine the number of years between an ancestral species and a descendant species. Because some species evolve at faster rates than others, these two measures of branch length are not always in direct proportion. The expected number of substitutions per site per year is often indicated with the Greek letter mu (μ). A model is said to have a strict molecular clock if the expected number of substitutions per year μ is constant regardless of which species' evolution is being examined. An important implication of a strict molecular clock is that the number of expected substitutions between an ancestral species and any of its present-day descendants must be independent of which descendant species is examined. Note that the assumption of a strict molecular clock is often unrealistic, especially across long periods of evolution. For example, even though rodents are genetically very similar to primates, they have undergone a much higher number of substitutions in the estimated time since divergence in some regions of the genome.
In 1990, Brigadier Oupa Gqozo deposed Sebe and ruled as a dictator—despite an initial promise of a swift return to civilian rule. During 1991 and 1992, many of the legal foundations of apartheid in South Africa were removed, undermining the rationale for the homelands' continued existence. The African National Congress pressed strongly for them to be reincorporated into South Africa. This was opposed by Gqozo and the other homeland leaders.
Sources: en.wikipedia.org
The medication is used to treat clear cell renal cell carcinoma, the most common histological subtype. The treatment phase is continuing treatment beyond three months. The patient has been issued an authority prescription for pazopanib. The patient must have stable or responding disease according to the Response Evaluation Criteria In Solid Tumours (RECIST). This treatment must be the sole tyrosine kinase inhibitor subsidised for this condition. Pazopanib has also demonstrated initial therapeutic properties in patients with aggressive fibromatosis (desmoid tumor), ovarian and non-small cell lung cancer. However, plans to apply to the EMA for a variation to include advanced ovarian cancer have been withdrawn and a license will not be sought in any country.
Here, the phosphorylated 5′ end of the RNA strand enters a conserved basic surface pocket and makes contacts through a divalent cation (an atom with two positive charges) such as magnesium and by aromatic stacking (a process that allows more than one atom to share an electron by passing it back and forth) between the 5′ nucleotide in the siRNA and a conserved tyrosine residue. This site is thought to form a nucleation site for the binding of the siRNA to its mRNA target. Analysis of the inhibitory effect of mismatches in either the 5' or 3' end of the guide strand has demonstrated that the 5' end of the guide strand is likely responsible for matching and binding the target mRNA, while the 3' end is responsible for physically arranging target mRNA into a cleavage-favorable RISC region. It is not understood how the activated RISC complex locates complementary mRNAs within the cell. Although the cleavage process has been proposed to be linked to translation, translation of the mRNA target is not essential for RNAi-mediated degradation. Indeed, RNAi may be more effective against mRNA targets that are not translated. Argonaute proteins are localized to specific regions in the cytoplasm called P-bodies (also cytoplasmic bodies or GW bodies), which are regions with high rates of mRNA decay; miRNA activity is also clustered in P-bodies. Disruption of P-bodies decreases the efficiency of RNAi, suggesting that they are a critical site in the RNAi process.
=== Other functions === Cholesterol translocation from outer to the inner mitochondrial membrane Activates mitochondrial cholesterol side-chain cleavage Import protein into mitochondrial matrix Anticoagulant function Modulates α-synuclein - malfunction of this process is thought to be a cause of Parkinson's disease.
By July 2019, this has not happened, according to The Record. Critics raised concerns that Hydro One will not experience stability as Premier Ford's government has a "record of reaching in to exert control." On March 21, 2019, Minister Rickford tabled Bill 87, the Fixing the Hydro Mess Act, which was given royal assent on May 9. Bill 87 overhauled the Ontario Energy Board and eliminated the Liberal's 2017 Fair Hydro Plan which the PC's said would save $442 million. The Liberal Plan "subsidized electricity with borrowed money" in response to a "public outcry over soaring hydro rates, particularly in rural areas." The Liberals created the Ontario Power Generation Inc (OPG Trust) as the Financial Services Manager to manage the debt. Bonnie Lysyk, the Auditor General, released a special report on October 17, 2017, which said the "structure of the plan" was in violation of the provincial government's accounting rules. She said that the Plan, which committed the government to discount consumer electricity rates for ten years, would cost the province "$21 billion in interest over the next 30 years." The 2017 AG report said that it would cost $4 billion more on the $18.4 billion loan to use the Ontario Power Generation (OPG Trust) than if the province took out the loan because the province would have a lower interest rate than the OPG Trust. The Ford government said that they would maintain [the] 25 per cent time-of-use rates, that was part of the Liberal's Fair Hydro Plan.
=== Semi-automated system === Blood volumes can also been measured in humans using the non-radioactive, carbon monoxide (CO) rebreathing technique. With this technique, a small volume of pure CO gas is inhaled and rebreathed for a few minutes. During rebreathing, CO binds to hemoglobin present in red blood cells. Based on the increase in blood CO after the rebreathing period, the volume of blood can be determined through the dilution principle.
Sources: en.wikipedia.org
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.