A practical reference on GHRH receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
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 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
| Property | Value | Notes |
|---|---|---|
| Primary target | GHRH receptor | G-protein-coupled receptor on pituitary somatotrophs |
| Half-life, long-acting form | Several days | Extended by covalent albumin binding |
| Half-life, short form | About 30 minutes | Cleared rapidly by peptidases and kidneys |
| Route in studies | Subcutaneous injection | Used in the published human trials |
| Main measured effect | Rise in GH and IGF-1 | Surrogate markers rather than clinical endpoints |
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.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
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.
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.
== Characteristics == Francium is one of the most unstable of the naturally occurring elements: its longest-lived isotope, francium-223, has a half-life of only 22 minutes. The only comparable element is astatine, whose most stable natural isotope, astatine-219 (the alpha daughter of francium-223), has a half-life of 56 seconds, although synthetic astatine-210 is much longer-lived with a half-life of 8.1 hours. All isotopes of francium decay into astatine, radium, or radon. Francium-223 also has a shorter half-life than the longest-lived isotope known of each element up to and including element 105, dubnium. Francium is an alkali metal whose chemical properties mostly resemble those of caesium. A heavy element with a single valence electron, it has the highest equivalent weight of any element. Liquid francium—if created—should have a surface tension of 0.05092 N/m at its melting point. Francium's melting point was estimated to be around 8.0 °C (46.4 °F); a value of 27 °C (81 °F) is also often encountered. The melting point is uncertain because of the element's extreme rarity and radioactivity; a different extrapolation based on Dmitri Mendeleev's method gave 20 ± 1.5 °C (68.0 ± 2.7 °F). A calculation based on the melting temperatures of binary ionic crystals gives 24.861 ± 0.517 °C (76.750 ± 0.931 °F). The estimated boiling point of 620 °C (1,148 °F) is also uncertain; the estimates 598 °C (1,108 °F) and 677 °C (1,251 °F), as well as the extrapolation from Mendeleev's method of 640 °C (1,184 °F), have also been suggested.
Rates of metformin-associated lactic acidosis are about nine per 100,000 persons/year, which is similar to the background rate of lactic acidosis in the general population. Systematic reviews from 2003 and 2022 concluded no data exists to definitively link metformin to lactic acidosis. Metformin-associated lactate production may also take place in the large intestine, which could potentially contribute to lactic acidosis in those with risk factors. The clinical significance of this is unknown, though, and the risk of metformin-associated lactic acidosis is most commonly attributed to decreased hepatic uptake rather than increased intestinal production.
=== Cardiovascular system === Nicotine exerts several significant effects on the cardiovascular system. Primarily, it stimulates the sympathetic nervous system, leading to the release of catecholamines. This activation results in an increase in heart rate and blood pressure, as well as enhanced myocardial contractility, which raises the workload on the heart. Additionally, nicotine causes systemic vasoconstriction, including constriction of coronary arteries, which can reduce blood flow to the heart. Long-term exposure to nicotine may impair endothelial function, potentially contributing to atherosclerosis. Furthermore, nicotine has been associated with the development of cardiac arrhythmias, particularly in individuals who already have underlying heart disease. The effects of nicotine can be differentiated between short-term and long-term use. Short-term nicotine use, such as that associated with nicotine replacement therapy (NRT) for smoking cessation, appears to pose little cardiovascular risk, even for patients with known cardiovascular conditions. In contrast, longer-term nicotine use may not accelerate atherosclerosis but could contribute to acute cardiovascular events in those with pre-existing cardiovascular disease. Many severe cardiovascular effects traditionally associated with smoking may not be solely attributable to nicotine itself. Cigarette smoke contains numerous other potentially cardiotoxic substances, including carbon monoxide and oxidant gases.
Sources: en.wikipedia.org
=== Surgery === When atherosclerosis has become severe and caused irreversible ischemia, such as tissue loss in the case of peripheral artery disease, surgery may be indicated. Vascular bypass surgery can re-establish flow around the diseased segment of the artery, and angioplasty with or without stenting can reopen narrowed arteries and improve blood flow. Coronary artery bypass grafting without manipulation of the ascending aorta has demonstrated reduced rates of postoperative stroke and mortality compared to traditional on-pump coronary revascularization. Atherectomy, which involves the removal of plaques instead of pushing them into the vessel wall, is a minimally invasive alternative to angioplasty.
=== Moisture dependence === The presence of water plays a crucial role in the mechanical behavior of natural fibers. Plants depend on water to help them grow. If the humidity was too high, then it would cause the plants to create mold and bacteria. Humidity would also increase the amount of pests around the plants. Hydrated, biopolymers generally have enhanced ductility and toughness. Water plays the role of a plasticizer, a small molecule easing passage of polymer chains and in doing so increasing ductility and toughness. When using natural fibers in applications outside of their native use, the original level of hydration must be taken into account. For example, when hydrated, the Young's Modulus of collagen decreases from 3.26 to 0.6 GPa and becomes both more ductile and tougher. Additionally the density of collagen decreases from 1.34 to 1.18 g/cm3.
==== Sabellid polychaetes ==== The sabellid polychaetes, or feather duster worms, have cartilage tissue with cellular and matrix specialization supporting their tentacles. They present two distinct extracellular matrix regions. These regions are an acellular fibrous region with a high collagen content, called cartilage-like matrix, and collagen lacking a highly cellularized core, called osteoid-like matrix. The cartilage-like matrix surrounds the osteoid-like matrix. The amount of the acellular fibrous region is variable. The model organisms used in the study of cartilage in sabellid polychaetes are Potamilla species and Myxicola infundibulum.
Sources: en.wikipedia.org
== Medical uses == Methocarbamol is a muscle relaxant used to treat acute, painful musculoskeletal spasms in a variety of musculoskeletal conditions. However, there is limited and inconsistent published research on the medication's efficacy and safety in treating musculoskeletal conditions, primarily neck and back pain. Methocarbamol injection may have a beneficial effect in the control of the neuromuscular spasms of tetanus. It does not, however, replace the current treatment regimen. It is not useful in chronic neurological disorders, such as cerebral palsy or other dyskinesias. Currently, there is some suggestion that muscle relaxants may improve the symptoms of rheumatoid arthritis; however, there is insufficient data to prove its effectiveness or to answer concerns regarding optimal dosing, choice of muscle relaxant, adverse effects, and functional status.
== Chemistry and pharmacokinetics == Phenformin hydrochloride is a white crystalline powder, with a melting point of 175–178 °C; it is soluble at 1 in 8 parts of water and 1 in 15 of ethanol, and practically insoluble in chloroform and ether. Phenformin is less polar and more lipid soluble and exhibits a higher affinity for mitochondrial membranes than metformin. Its dissociation constant (pKa) is 2.7, 11.8 (at 32 °C), and log P = –0.8. Phenformin is well absorbed after oral administration. The major metabolic reaction is aromatic hydroxylation to form 4-hydroxyphenformin, which is then conjugated with glucuronic acid. Up to about 50% of a dose is excreted in the urine in 24 h, about two–thirds in the form of unchanged drug and one–third as the hydroxy metabolite. Following a single oral dose of 50 mg to eight subjects, peak plasma concentrations of 0.08–0.18 mg/L (mean 0.13) were attained in about 3 h; plasma concentrations were higher in four subjects who were poor metabolisers of debrisoquine in comparison with the four extensive metabolisers. Following daily oral doses of 50 mg three times a day to eight subjects, plasma concentrations of 0.10–0.24 mg/L (mean 0.18) were reported 2 h after a dose. Plasma half-life of phenformin is 10–15 h. Phenformin protein binding in plasma is about 12–20%.
=== Diversion of international aid === The United Nations World Food Programme has accused the Houthis of diverting food aid and illegally removing food lorries from distribution areas, with rations sold on the open market or given to those not entitled to them. The WFP has also warned that aid could be suspended to areas of Yemen under the control of Houthi rebels due to "obstructive and uncooperative" Houthi leaders that have hampered the independent selection of beneficiaries. WFP spokesman Herve Verhoosel stated "The continued blocking by some within the Houthi leadership of the biometric registration ... is undermining an essential process that would allow us to independently verify that food is reaching ... people on the brink of famine". The WFP has warned that "unless progress is made on previous agreements we will have to implement a phased suspension of aid". The Norwegian Refugee Council has stated that they share the WPF's frustrations and reiterate to the Houthis to allow humanitarian agencies to distribute food.
Sources: en.wikipedia.org
It binds the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Receptor activation raises cyclic AMP and promotes release of stored growth hormone granules. Because the peptide persists longer than natural releasing hormone, stimulation is prolonged rather than brief.
The drug affinity complex links the peptide to serum albumin through a covalent bond. The conjugate is too large to be filtered quickly by the kidneys and is shielded from enzymatic breakdown. This extends the apparent half-life from roughly minutes to several days.
Long-term safety and any clinical benefit are unestablished. Published human data cover small groups over limited periods and focus on hormone levels rather than health outcomes. Whether prolonged elevation of growth hormone and insulin-like growth factor 1 is beneficial or harmful is an open question.
It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.