modified GRF(1-29) comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-04-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
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 |
|---|---|---|
| Appearance | White to off white powder | Typical lyophilized form |
| Water solubility | Soluble | May need a small organic co-solvent |
| Purity assessment | Chromatographic peak area | Most certificates report a percentage figure |
| Storage temperature | Minus 20 C or lower | Dry, dark, sealed container |
| Identity check | Electrospray mass spectrometry | Compared against theoretical mass |
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.
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.
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.
Keloids grow extensively beyond the wound margins and tend to persist or even worsen over time. They are relatively difficult to treat due to their high risk of recurrence. Keloids are more common in people with darker skin tones and often occur in individuals with a genetic predisposition. Keloids are the most extreme type of scarring since minor wounds such as insect bites or piercings can all lead to an elevated tissue area. Patients may experience psychological trauma if their scars are not well-controlled. Therefore, the prevention of wound formation is crucial to them. They should avoid undergoing any unnecessary invasive procedures or cosmetic surgeries. The beneficial effects of silicone gel sheeting on the treatment and prevention of these two scars have been confirmed. Since most patients develop hypertrophic and keloid scars within 3 months after surgery or injury, the silicone gel sheeting therapy should be started in the early repair phase to achieve an optimal therapeutic effect. The maturity of scars takes over a year; therefore, silicone treatment is also effective in scars aged over 12 months. The therapy usually requires 6 to 12 months of constant wear to achieve optimum results. Recent data suggest that the combination of silicone gel sheeting and pressure therapy can improve post-traumatic scar healing.
In glaucoma visual field defects result from damage to the retinal nerve fiber layer (RNFL). Field defects are seen mainly in primary open angle glaucoma. Because of the unique anatomy of the RNFL, many noticeable patterns are seen in the visual field. Most of the early glaucomatous changes are seen within the central visual field, mainly in Bjerrum's area, 10-20° from fixation. The following are the common glaucomatous field defects:
=== Epidermal barrier === Necrobiosis, mainly affecting dermis and subcutaneous tissue, can also impact the epidermis. TNF-α and IFN-γ impair keratinocyte function, inhibiting keratinocyte proliferation and migration, two processes essential for reepithelialization and wound closure. Chronic keratinocyte dysfunction can lead to tissue atrophy. Furthermore, inflammatory signaling may downregulate key cell-cell adhesion molecules such as E-cadherin and β-catenin, compromising epidermal tight junctions and leading to skin barrier dysfunction. All of these factors impact the epidermal integrity and barrier.
== Producers == As of October 2019, there were two producers of iodine-125, the McMaster Nuclear Reactor in Hamilton, Ontario, Canada; and a VVR-SM research reactor in Uzbekistan. The McMaster reactor is presently the largest producer of iodine-125, producing approximately 60 per cent of the global supply in 2018; with the remaining global supply produced at the reactor based in Uzbekistan. Annually, the McMaster reactor produces enough iodine-125 to treat approximately 70,000 patients. In November 2019, the research reactor in Uzbekistan shut down temporarily in order to facilitate repairs. The temporary shutdown threatened the global supply of the radioisotope by leaving the McMaster reactor as the sole producer of iodine-125 during the period. Prior to 2018, the National Research Universal (NRU) reactor at Chalk River Laboratories in Deep River, Ontario, was one of three reactors to produce iodine-125. However, on March 31, 2018, the NRU reactor was permanently shut down ahead of its scheduled decommissioning in 2028, as a result of a government order. The Russian nuclear reactor equipped to produce iodine-125, was offline as of December 2019.
Sources: en.wikipedia.org
This alliance did not last for long however, and in February 1979, Habré deployed his forces around N'Djamena. These launched their attack on 11 February. The ENT and the French forces deployed there attempted to help Malloum's embattled government. In reaction, Habré declared that he would not be able to guarantee the security of the expatriates living in the city, should the bombardments continue. This caused the French forces to stop the bombardment. The foreigners were then evacuated by French transport aircraft, followed by the French troops present there. This caused the ENT to completely cease its operations: without access to the French personnel that was operating its aircraft, it was de facto disbanded.
Pd complexes of SPhos catalyze Suzuki-Miyaura coupling reactions. This ligand enables the cross-coupling of heteroaryl, electron-rich and electron-poor aryl, and vinylboronic acids with a variety of aryl and heteroaryl halides under mild reaction conditions. SPhos has also been used in the Pd-catalyzed borylation of aryl and heteroaryl chlorides.
Moscow is one of the largest centers for science in Russia. The headquarters of the Russian Academy of Sciences are located in the city, as well as research and applied science institutions. Moscow also contains the following institutions:
Sources: en.wikipedia.org
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.
Yes. Degradation proceeds faster once the powder is dissolved, especially at room temperature or after multiple freeze and thaw cycles. Working solutions are often aliquoted to avoid repeated handling. Lyophilized powder held cold and dry retains its properties far longer.
Truncated sequences, oxidized residues and aggregated forms can all elute near the main peak. Reversed phase chromatography resolves many of these species, so the number of peaks is a useful indicator of synthesis quality. A single peak does not by itself prove correct sequence, which is why mass confirmation is paired with it.
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.