A practical reference on modified GRF(1-29): 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.
Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.
Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic GHRH analogue | Built on a 29 residue sequence |
| Primary target | GHRH receptor (GHRHR) | Class B G protein coupled receptor |
| Unconjugated half life | Minutes | Limited by protease degradation |
| Key modification | Four residue substitutions | Positions 2, 8, 15 and 27 |
| Common synonym | Modified GRF(1-29) | Usually denotes the form without DAC |
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
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.
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.
In 1897, German physicist and chemist Walther Nernst developed the Nernst lamp, a form of incandescent lamp that used a ceramic globar and did not require enclosure in a vacuum or inert gas. Twice as efficient as carbon filament lamps, Nernst lamps were briefly popular until overtaken by lamps using metal filaments.
Motif discovery happens in three major phases. A pre-processing stage where sequences are meticulously prepared in assembly and cleaning steps. Assembly involves selecting sequences that contain the desired motif in large quantities, and extraction of unwanted sequences using clustering. Cleaning then ensures the removal of any confounding elements. Next there is the discovery stage. In this phase sequences are represented using consensus strings or Position-specific Weight Matrices (PWM). After motif representation, an objective function is chosen and a suitable search algorithm is applied to uncover the motifs. Finally the post-processing stage involves evaluating the discovered motifs.
Exhausted, I then slept, to awake next morning refreshed, with a clear head, though still somewhat tired physically. A sensation of well-being and renewed life flowed through me. Breakfast tasted delicious and gave me extraordinary pleasure. When I later walked out into the garden, in which the sun shone now after a spring rain, everything glistened and sparkled in a fresh light. The world was as if newly created. All my senses vibrated in a condition of highest sensitivity, which persisted for the entire day. During a speech on his 100th birthday in 2006, Hofmann additionally said of LSD:
Sources: en.wikipedia.org
One of these requirements is that the limiting oxygen index of EPS as measured by ASTM D2863 be greater than 24 volume %. Typical EPS has an oxygen index of around 18 volume %; thus, a flame retardant is added to styrene or polystyrene during the formation of EPS. The boards containing a flame retardant when tested in a tunnel using test method UL 723 or ASTM E84 will have a flame spread index of less than 25 and a smoke-developed index of less than 450. ICC-ES requires the use of a 15-minute thermal barrier when EPS boards are used inside of a building. According to the EPS-IA ICF organization, the typical density of EPS used for insulated concrete forms (expanded polystyrene concrete) is 1.35 to 1.80 pounds per cubic foot (21.6 to 28.8 kg/m3). This is either Type II or Type IX EPS according to ASTM C578. EPS blocks or boards used in building construction are commonly cut using hot wires.
Etoperidone is as an antagonist of several receptors in the following order of potency: 5-HT2A receptor (36 nM) > α1-adrenergic receptor (38 nM) > 5-HT1A receptor (85 nM) (may be a partial agonist) > α2-adrenergic receptor (570 nM); it has only very weak or negligible affinity for blocking the following receptors: D2 receptor (2,300 nM) > H1 receptor (3,100 nM) > mACh receptors (>35,000 nM). In addition to its receptor blockade, etoperidone also has weak affinity for the monoamine transporters as well: serotonin transporter (890 nM) > norepinephrine transporter (20,000 nM) > dopamine transporter (52,000 nM).
=== Pulmonary embolism === As of 2019, alteplase is the most commonly used medication to treat pulmonary embolism. Alteplase has a short infusion time of 2 hours and a half-life of 4–6 minutes. Alteplase has been approved by the US Food and Drug Administration, and treatment can be done via systemic thrombolysis or catheter-directed thrombolysis. Systemic thrombolysis can quickly restore right ventricular function, heart rate, and blood pressure in patients with acute PE. However, standard doses of alteplase used in systemic thrombolysis may lead to massive bleeding, such as intracranial hemorrhage, particularly in older patients. A systematic review has shown that low-dose alteplase is safer than and as effective as the standard amount.
Sources: en.wikipedia.org
pnuC a NR/NMN transporter (most common; majority of Lactobacillales examples) nadA a Quinolate synthase (first committed step of de novo NAD⁺ biosynthesis; common in Planctomycetota) pncB a Nicotinate phosphoribosyltransferase (nicotinic acid salvage) ecf an ECF (energy-coupling factor) transporter cassette, likely involved in NAD⁺ homeostasis tsx a Nucleoside-specific channel
On television, d'Abo played Ta'Ra, an alien medical officer in the science fiction miniseries Something Is Out There (1988), which was followed by a six-episode NBC mini-series of the same name, and she played Anne Summerton in the TV adaptation of Jeffrey Archer's novel Not a Penny More, Not a Penny Less (1990) directed by Clive Donner. D'Abo had a supporting role as a pretentious stained-glass artist in the low-budget British comedy Leon the Pig Farmer (1992). She appeared in the 1994 film The Browning Version and starred in Timelock (1996). D'Abo has had roles in various low-budget, straight-to-video action, horror and fantasy films such as Tomcat: Dangerous Desires (1992), as well as guest roles on television shows Tales from the Crypt (1993), Red Shoe Diaries (1992) and Murder, She Wrote (1992). She reunited with her James Bond director John Glen for a guest-starring role on the television series Space Precinct and for the feature film The Point Men (2001). Glen later said that he cast her in three different projects was because she was one of his favourite actresses. She played the mother of Lara (played by Keira Knightley) in the television miniseries version of Doctor Zhivago (2002), and she was Queen Hecuba in the Emmy-nominated miniseries Helen of Troy (2003). She had a small role in the French film L'Enfer (Hell, 2005), directed by Danis Tanovic whose stars included fellow Bond Girl Carole Bouquet. D'Abo and John Cork wrote the book Bond Girls Are Forever, published in 2002, which is a tribute to the women who have played the role of a Bond girl.
== Research == Hong's research focuses on elucidating the structure, dynamics and mechanism of membrane proteins using ssNMR. She is particularly known for her in-depth study of the Matrix-2 (M2) proteins of influenza A viruses, which are responsible for all flu pandemics in history. M2 is an acid-activated proton channel and a membrane scission protein of the influenza virus. Hong's ssNMR studies have provided insights into the proton-conduction mechanism of this channel, by quantifying the proton transfer rates and equilibria between water and the proton-selective histidine residue. She showed that the antiviral drug amantadine inhibits proton conduction by direct occlusion of the channel pore. She determined the cholesterol-binding structure of the M2 protein, which sheds light on how cholesterol mediates M2's membrane scission function. In 2020 she determined both the influenza B M2 protein structure and the SARS-CoV-2 envelope protein structure, the latter in rapid response to COVID-19. The 1.5 Å BM2 structures in the closed and open states revealed different activation mechanisms of BM2 compared to influenza AM2. The 2.1 Å SARS-CoV-2 envelope protein structure forms the basis for antiviral drug design. Other membrane proteins that Hong's group has studied include β-hairpin antimicrobial peptides, channel-forming colicins, and viral fusion proteins. She determined the structure of the membrane toroidal pores formed by the antimicrobial peptide protegrin-1, which explained the membrane-disruptive mechanism of this peptide.
Sources: en.wikipedia.org
The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.
DAC stands for drug affinity complex, a term describing the maleimidopropionic acid linker. This group forms a covalent bond with the cysteine residue on serum albumin after administration. The resulting adduct is what extends the circulating half life from minutes to days.
No. It is entirely synthetic and does not correspond to any known endogenous peptide. The design starts from human growth hormone releasing hormone and introduces deliberate substitutions. Any biological effect comes from mimicking the natural hormone at its receptor.
Mass spectrometry establishes whether the observed molecular weight matches the calculated sequence mass. Chromatographic retention and fragment mapping add further confidence about sequence and composition. A single technique alone is rarely treated as sufficient evidence of identity.