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 2026-03-21 and is reviewed periodically as new material appears.
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.
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.
| 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 |
The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.
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.
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.
=== Controversy === In 2015, ex-Transportation corps commander Major General Liu Zhanqi, ex-Transportation corps Political commissar Major General Wang Xin and ex-Transportation Corps Chief engineer Major General Miao Guirong were arrested on 16 June, 31 July and 15 September respectively on corruption-related charges as part of the anti-corruption campaign under Xi Jinping. As of 16 September 2015, a total of 43 people were arrested in relation to the case.
Dermal macrophages are primarily populated in the dermis of the skin as they are specialised in skin homeostasis and repair. There are three inter-linked stages in skin wound healing: inflammation, tissue formation, and maturation. Dermal macrophages serve the function of bridging the three stages of wound healing. The first stage occurs from day 0 to 5 post-injury. This stage is an inflammatory response induced by dermal macrophages to initiate the tissue repairing process. Similar to their functions in innate immunity, dermal macrophages stimulate an inflammatory response during the first stage of wound repair by releasing pro-inflammatory factors. This allows infiltration of immune cells and factors facilitating tissue regeneration. Dermal macrophages are associated with the production of proliferation factors such as TGFβ1 and VEGF-A. The factors are produced to initiate the second stage, tissue formation. Tissue formation occurs from day 5 to 10 post-injury. In this stage, dermal macrophages' primary role is to generate a primary structure for wound repairing via granulation and collagen deposition. They also mediate re-epithelialisation and neo-angiogenesis by producing TGFβ1 and VEGF-A, as in the inflammation stage. Dermal macrophages are essential in the transition between the second and third stages. Deficiency in dermal macrophages might induce unfavourable morphological changes in the wound because of compromised removal of tissue debris via phagocytosis. Dermal macrophages mediate the final stage of tissue maturation and wound remodelling.
== Fourth- and fifth-hand smoke == More controversially, the related concepts of fourth-hand smoke and even fifth-hand smoke have also been proposed as well to refer to further orders of theoretical contamination from tobacco smoke.
DCI John Caldwell, an off duty Police Service of Northern Ireland officer, is injured in Omagh after being shot by suspected New IRA gunman. 23 February Labour leader Sir Keir Starmer outlines the five key issues that his party will focus on during the run up to the 2024 general election: higher economic growth, clean energy, improving the NHS, reforming the justice system, and raising education standards. Environment Secretary Thérèse Coffey, commenting on the vegetable shortage, tells MPs "we anticipate the situation will last about another two to four weeks". Three men are arrested in relation to the previous evening's shooting of DCI John Caldwell. 24 February The British Medical Association announces that junior doctors in England will begin a three-day strike on 13 March. An earthquake measuring 3.7 magnitude strikes Brynmawr, Blaenau Gwent at 11.59pm. COVID-19 in the UK: Office for National Statistics data for the week up to 14 February indicates COVID-19 cases continued to rise in England, Scotland and Wales, but remained uncertain in Northern Ireland. In England, the estimated number of people testing positive for COVID-19 was 1,223,000 (or 2.18% of the population and around 1 in 45 people). 27 February New Transgender Policy Guidance for England and Wales came into force on 27 February 2023 under which transgender women offenders would no longer be housed in women's prisons if they had male genitalia or had committed sex crimes.
Sources: en.wikipedia.org
Iodine absorbed by the body is almost completely stored in the thyroid gland and has a biological half-life of about 120 days. If the iodine is radioactive (131I), it can irradiate and damage the thyroid gland in high doses during this time. Because the thyroid gland can only absorb a limited amount of iodine, prophylactic administration of non-radioactive iodine may result in iodine blockade. Potassium iodide in tablet form (colloquially known as "iodine tablets") reduces the uptake of radioactive iodine into the thyroid by a factor of 90 or more, thus acting as a radioprotector. All other radiation damage remains unaffected by taking iodine tablets. In Germany, the Potassium Iodide Ordinance (KIV) was enacted in 2003 to ensure "the supply of the population with potassium iodide-containing medicines in the event of radiological incidents". § 1 kiv (in German) Potassium iodide is usually stored in communities near nuclear facilities for distribution to the population in the event of a disaster. People over the age of 45 should not take iodine tablets because the risk of side effects is higher than the risk of developing thyroid cancer. In Switzerland, as a precautionary measure, tablets have been distributed every five years since 2004 to the population living within 20 km of nuclear power plants (from 2014, 50 km). In Austria, large stocks of iodine tablets have been kept in pharmacies, kindergartens, schools, the army and the federal reserve since 2002.
=== Overview === The certification of isotopic reference materials is relatively complex. Like most aspects of reporting isotopic compositions it reflects a combination of historical artifacts and modern institutions. As a result, the details surrounding the certification of isotopic reference materials varies by element and chemical compound. As a general guideline, the isotopic composition of primary and original calibration reference materials were used to define the isotopic scales and so have no associated uncertainty. Updated calibration materials are generally certified by IAEA and important reference materials for two-point isotopic scales (SLAP, LSVEC) were reached through interlaboratory comparison. The isotopic composition of additional reference materials are either established through individual analytical facilities or through interlaboratory comparisons but often lack an official IAEA certification. There are certified values for most of the materials listed in Table 1, about half of the materials listed in Tables 2–7, and few of the materials in Table 8.
==== Armenia ==== According to a 2020 report, there are 32 think tanks or similar institutions in Armenia. The government closed the Noravank Foundation, a government-affiliated think tank, in 2018 after almost two decades of operation. However, other think tanks continue to operate, include the Caucasus Institute, the Caucasus Research Resource Center-Armenia (CRRC-Armenia) (which publishes the "Caucasus Barometer" annual public opinion survey of the South Caucasus, the "Enlight" Public Research Center, and the AMBERD research center at the Armenian State University of Economics.
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.
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.