The short version of IGF-1 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-05-21. Anything still debated is marked as such rather than presented as settled.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
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.
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.
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.
Data from the Moneyfacts Group suggests the average rate on a two-year fixed-term mortgage has fallen below 6% for the first time since June 2023. The Court of Session in Edinburgh rules that the UK government acted lawfully by blocking the Gender Recognition Reform (Scotland) Bill from becoming law, and rejects the Scottish Government's appeal against the decision. At the Old Bailey, Paul Bryan is sentenced to life imprisonment with a minimum of 24 years for the 1984 murder of Roman Szalajko at the victim's south London home. Bryan assumed the identity of a dead man with the same name, but was traced through a fingerprint match in 2022. After footballer Joey Barton suggests that women "should not be talking with any kind of authority" about men's football, Chelsea manager Emma Hayes says women are "routinely used to dealing with systemic misogyny and bullying" in football. Wham!'s Last Christmas tops the singles chart for the fourth time with Mariah Carey's All I Want For Christmas Is You taking the second spot. A week after the death of Shane MacGowan from The Pogues, Fairytale of New York rises to number four. 9 December Yellow weather warnings are in place for much of the UK as two successive storms, Elin and Fergus, reach the UK from the Atlantic, bringing high winds and heavy rain. The royal family reveal their Christmas card images with King Charles III choosing a photograph from his coronation earlier this year for his second Christmas as monarch.
the level of transcription of a gene gives only a rough estimate of its level of translation into a protein. An mRNA produced in abundance may be degraded rapidly or translated inefficiently, resulting in a small amount of protein. as mentioned above, many proteins experience post-translational modifications that profoundly affect their activities; for example, some proteins are not active until they become phosphorylated. Methods such as phosphoproteomics and glycoproteomics are used to study post-translational modifications. many transcripts give rise to more than one protein, through alternative splicing or alternative post-translational modifications. many proteins form complexes with other proteins or RNA molecules, and only function in the presence of these other molecules. protein degradation rate plays an important role in protein content. Reproducibility. One major factor affecting reproducibility in proteomics experiments is the simultaneous elution of many more peptides than mass spectrometers can measure. This causes stochastic differences between experiments due to data-dependent acquisition of tryptic peptides. Although early large-scale shotgun proteomics analyses showed considerable variability between laboratories, presumably due in part to technical and experimental differences between laboratories, reproducibility has been improved in more recent mass spectrometry analysis, particularly on the protein level.
== Pathophysiology == Hutchinson–Gilford progeroid syndrome (HGPS) is an extremely rare autosomal dominant genetic disorder in which symptoms resembling aspects of aging are manifested at an early age. Its occurrence is usually the result of a sporadic germline mutation; although HGPS is genetically dominant, people rarely live long enough to have children, preventing them from passing the disorder on in a hereditary manner.
== External links == Gas+chromatography-mass+spectrometry at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Golm Metabolome Database, a mass spectral reference database of plant metabolites
By the 19th century, it had become increasingly recognised that migraine was not always confined to one side of the head. Consequently, the historical term hemicrania came to encompass conditions now classified as migraine, although it may also have included other headache disorders. In 1887, the French librarian Louis Hyacinthe Thomas distinguished two forms of migraine, "migraine ophthalmique" and "migraine vulgaire", corresponding broadly to what are now known as migraine with aura and migraine without aura. Although numerous treatments for migraine had been attempted, it was not until 1868 that ergot was introduced as a treatment. Canadian physician William Osler, included a chapter on migraine in his 1892 The Principles and Practice of Medicine, the gold standard medical text of the day. He described the treatments commonly used by physicians, including ergot, cannabis, bromides, caffeine, and pain-relieving medicines including antipyrin and phenacetin.
Sources: en.wikipedia.org
The vocalisations of emus mostly consist of various booming and grunting sounds. The booming is created by the inflatable throat pouch; the pitch can be regulated by the bird and depends on the size of the aperture. Most of the booming is done by females; it is part of the courtship ritual, is used to announce the holding of territory and is issued as a threat to rivals. A high-intensity boom is audible 2 kilometres (1.2 mi) away, while a low, more resonant call, produced during the breeding season, may at first attract mates and peaks while the male is incubating the eggs. Most of the grunting is done by males. It is used principally during the breeding season in territorial defence, as a threat to other males, during courtship and while the female is laying. Both sexes sometimes boom or grunt during threat displays or on encountering strange objects. On very hot days, emus pant to maintain their body temperature. Their lungs work as evaporative coolers and, unlike some other species, the resulting low levels of carbon dioxide in the blood do not appear to cause alkalosis. For normal breathing in cooler weather, they have large, multifolded nasal passages. Cool air warms as it passes through into the lungs, extracting heat from the nasal region. On exhalation, the emu's cold nasal turbinates condense moisture back out of the air and absorb it for reuse. As with other ratites, the emu has great homeothermic ability, and can maintain this status from −5 to 45 °C (23 to 113 °F). The thermoneutral zone of emus lies between 10 and 30 °C (50 and 86 °F).
The two substrates of this enzyme are propylene glycol and oxidised nicotinamide adenine dinucleotide phosphate (NADP+). Its products are L-lactaldehyde, reduced NADPH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is propane-1,2-diol:NADP+ oxidoreductase. Other names in common use include lactaldehyde (reduced nicotinamide adenine dinucleotide phosphate), reductase, NADP+-1,2-propanediol dehydrogenase, propanediol dehydrogenase, 1,2-propanediol:NADP+ oxidoreductase, and lactaldehyde reductase (NADPH).
== Suitability == As this method involves at least 2 rounds of washing, it may not be suitable for screening transient protein interactions, unlike the yeast two-hybrid method or in vivo crosslinking with photo-reactive amino acid analogs. However, it is a good method for testing stable protein interactions and allows various degrees of investigation by controlling the number of times the protein complex is purified.
=== Fourier transform ion cyclotron resonance mass spectrometry === FT- ICR EI - MS can be used for analysis of three vacuum gas oil (VGO) distillation fractions in 295-319 °C, 319-456 °C and 456-543 °C. In this method, EI at 10 eV allows soft ionization of aromatic compounds in the vacuum gas oil range. The compositional variations at the molecular level were determined from the elemental composition assignment. Ultra-high resolving power, small sample size, high reproducibility and mass accuracy (<0.4ppm) are the special features in this method. The major product was aromatic hydrocarbons in all three samples. In addition, many sulfur-, nitrogen-, and oxygen-containing compounds were directly observed when the concentration of this heteroatomic species increased with the boiling point. Using data analysis it gave the information about compound types (rings plus double bonds), their carbon number distributions for hydrocarbon and heteroatomic compounds in the distillation fractions, increasing average molecular weight (or carbon number distribution) and aromaticity with increasing boiling temperature of the petroleum fractions.
French president Emmanuel Macron initially expressed joy, declaring on social media that "Maduro is a dictator, and his departure is good news for Venezuelans. He confiscated the freedom of his people and stole the 2024 elections." However, days later he nuanced his message, saying that the method employed by the Americans "does not have the support or approval" of France. United Kingdom prime minister Keir Starmer said that he was happy for the fall of Maduro, and he would wait to know the facts before commenting further. José Antonio Kast, the president-elect of Chile, stated that Maduro was not the legitimate president of Venezuela, had "destabilized Latin America", called his capture "great news", and remarked that work remained and the "governments of Latin America must ensure that the entire apparatus of the regime relinquishes power and is held accountable". Spanish prime minister Pedro Sánchez urged de-escalation, stating that "[i]nternational law and the principles of the U.N. Charter must be respected"; this was echoed by European Union (EU) foreign policy chief and European Commission vice-president Kaja Kallas. The governments of Brazil, Colombia, Mexico, Spain, Uruguay, and the outgoing administration in Chile issued a joint statement rejecting the US action and expressed their concern saying that it could "constitute an extremely dangerous precedent for peace and regional security and endanger the civilian population".
Sources: en.wikipedia.org
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
It acts on the growth hormone-releasing hormone receptor found on pituitary somatotroph cells. Activation of that receptor triggers growth hormone release through a cyclic AMP dependent pathway.