The short version of GRF(1-29) fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-03 and is reviewed periodically as new material appears.
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.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
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.
Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (with DAC) | ~3647 Da | Calculated from the full amino acid sequence |
| Molecular weight (without DAC) | ~3368 Da | Mod GRF(1-29) variant |
| Appearance | White lyophilized powder | Typical form supplied for research |
| Solubility | Soluble in water | Dissolves in aqueous buffers |
| Receptor target | GHRH receptor | Expressed on pituitary somatotroph cells |
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.
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.
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 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.
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.
There are controversies around GMOs generally on several levels, including whether making them is ethical, issues concerning intellectual property and market dynamics; environmental effects of GM crops; and GM crops' role in industrial agricultural more generally. There are also specific controversies around pharming.
Seventeen yachts and 167 crew started the first race of 27,500 nmi (50,900 km), which began from Portsmouth, United Kingdom, on 8 September 1973. Approximately 3000 spectator boats set out to witness the historic start. The first race was won by Mexican amateur Ramón Carlín in a Swan 65 yacht, Sayula II. Sayula II was followed by Adventure, Grand Louis and Kriter. The original course was designed to follow the route of the square riggers, which had carried cargo around the world during the 19th Century. From 2001 the ownership of the race was taken over by Volvo and Volvo Cars and the race was renamed the 'Volvo Ocean Race'. Stopover ports were added in Germany, France, and Sweden being Volvo's three biggest car markets in Europe. Winning the race does not attract a cash prize, as the feat of competing is presented as sufficient reward. Many of the crew in the Volvo Ocean Race race crew other professional teams in other high-profile events, such as the Olympic Games, Sydney to Hobart Yacht Race, the America's Cup, or the Fastnet Race. The worst weather conditions are usually encountered in the Southern Ocean where waves sometimes top 150 feet (46 m) and winds can reach 70 knots (130 km/h). The 2017–18 race covered 45,000 nautical miles, which is the longest route in its history.
==== Medical records ==== Police searches of Letby's home recovered sensitive medical documents, including nursing handover sheets, resuscitation records and blood‑gas printouts. A total of 257 sheets were found, 21 of which related to infants she was later accused of harming. Letby told the court that she often forgot to remove paperwork from her pockets after shifts and described herself as someone who "collect[ed] paper". She also said she had been unable to destroy the documents, although a paper shredder was found in her home.
In 1945, Moyer patented the methods for production and isolation of penicillin. He could not obtain patents in the US as an employee of the NRRL, but filed for patents with the British Patent Office. He gave the license to a US company, Commercial Solvents Corporation. When Fleming learnt of the American patents on penicillin production, he was incensed and commented:I found penicillin and have given it free for the benefit of humanity. Why should it become a profit-making monopoly of manufacturers in another country? The patenting of penicillin-related technologies by US companies gave rise to a myth in the UK that British scientists had done the work but American ones garnered the rewards. When the Rockefeller Foundation published its annual report in 1944, The Evening News contrasted the foundation's generous support of the Oxford team's work with that of the parsimonious MRC. In April 1945, the British firm Glaxo signed agreements with Squibb and Merck under which it paid 5 per cent royalties on its sales of penicillin for five years in return for the use of their deep submergence fermentation techniques. Glaxo paid almost £500,000 (equivalent to £10,800,000 in 2025) in royalties between 1946 and 1956. The controversy over patents led to the establishment of the UK National Research Development Corporation (NRDC) in June 1948. This organisation collected government patents and charged royalties on them.
== Chemistry == The bark is known to be rich in tannins, saponins, alkaloids, lipids, phytosterols, glucosides, xylose, rhamnose, arabinose, lupeol, methoxychalcones, and kukulkanins. Additionally, Mimosa tenuiflora contains labdane diterpenoids.
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== Use in cell culture == Together with other major components of the ECM, such as collagens and fibronectin, laminins have been used to enhance mammalian cell culture, especially in the case of pluripotent stem cells, as well as some primary cell cultures, which can be difficult to propagate on other substrates. Two types of naturally sourced laminins are commercially available: Laminin-111, extracted from mouse sarcomas, and laminin mixtures from human placenta, which may primarily correspond to laminin-211, 411, or 511, depending on the provider. The various laminin paralogs are practically impossible to isolate from tissues in pure form due to extensive cross-linking and the need for harsh extraction conditions, such as proteolytic enzymes or low pH, that cause degradation. Therefore, recombinant laminins have been produced since the year 2000. This made it possible to test if laminins could have a significant role in vitro as they have in the human body. In 2008, two groups independently showed that mouse embryonic stem cells can be grown for months on top of recombinant laminin-511. Later, Rodin et al. showed that recombinant laminin-511 can be used to create a xeno-free and defined cell culture environment to culture human pluripotent ES cells and human iPS cells.
Treatment options include surgery to remove the tumor, medications, and radiation therapy. Surgery is usually the preferred treatment; the smaller the tumor, the more likely surgery will be curative. If surgery is contraindicated or not curative, somatostatin analogues or GH receptor antagonists may be used. Radiation therapy may be used if neither surgery nor medications are completely effective. Without treatment, life expectancy is reduced by 10 years; with treatment, life expectancy is not reduced.
A political battle erupted over the People's Budget, which was rejected by the House of Lords and for which the government obtained an electoral mandate at the January 1910 election. The election resulted in a hung parliament, with the government left dependent on the Irish Nationalists. Although the Lords now passed the budget, the government wished to curtail their power to block legislation. Asquith was required by King George V to fight a second general election in December 1910 (whose result was little changed from that in January) before he agreed, if necessary, to create hundreds of Liberals peers. Faced with that threat, the Lords voted to give up their veto power and allowed the passage of the Parliament Act 1911. As the price of Irish support, Asquith was now forced to introduce a third Home Rule bill in 1912. Since the House of Lords no longer had the power to block the bill, but only to delay it for two years, it was due to become law in 1914. The Unionist Ulster Volunteers, led by Sir Edward Carson, launched a campaign of opposition that included the threat of a provisional government and armed resistance in Ulster. The Ulster Protestants had the full support of the Conservatives, whose leader, Bonar Law, was of Ulster-Scots descent. Government plans to deploy troops into Ulster had to be cancelled after the threat of mass resignation of their commissions by army officers in March 1914 (see Curragh Incident). Ireland seemed to be on the brink of civil war when the First World War broke out in August 1914.
Sir Frederick Gowland Hopkins (20 June 1861 – 16 May 1947) was an English biochemist who was awarded the Nobel Prize in Physiology or Medicine in 1929, with Christiaan Eijkman, for the discovery of vitamins. He also discovered the amino acid tryptophan, in 1901. He was President of the Royal Society from 1930 to 1935.
Memorials to the attacks include the National September 11 Memorial & Museum in New York City; the Pentagon Memorial in Arlington County, Virginia; and the Flight 93 National Memorial at the Pennsylvania crash site.
Sources: en.wikipedia.org
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.
The maleimide group forms a covalent link with albumin, an abundant blood protein. This attachment slows clearance, so a single administration persists much longer than the unmodified peptide. The feature is the main reason the two variants are handled differently in study design.
It is not an approved therapeutic product in major regulatory jurisdictions. It appears in research chemical catalogs and scientific literature rather than pharmacy shelves. Clinical development was limited and did not reach approval.
The mass difference from the linker is large enough for routine detection by mass spectrometry. The unconjugated form gives a single sharp signal at its expected weight. Material that has already reacted with albumin shows a much higher mass and a broadened chromatographic peak.