The short version of drug affinity complex fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-16 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C152H252N44O42 | Cited for the form without the drug affinity complex |
| Molecular weight | About 3368 Da | Reported value for modified GRF(1-29) |
| Appearance | White to off-white powder | Lyophilised solid as usually supplied |
| Solubility | Soluble in water and polar solvents | Clarity depends on purity and salt content |
| Typical storage | -20 C or below, dry | Protect from light and repeated warming cycles |
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.
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.
CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.
Dopamine may be converted into norepinephrine by the enzyme dopamine β-hydroxylase, which can be further modified by the enzyme phenylethanol N-methyltransferase to obtain epinephrine. Since L-DOPA is the precursor for the neurotransmitters dopamine, noradrenaline and adrenaline, tyrosine hydroxylase is therefore found in the cytosol of all cells containing these catecholamines. This initial reaction catalyzed by tyrosine hydroxylase has been shown to be the rate limiting step in the production of catecholamines. The enzyme is highly specific, not accepting indole derivatives - which is unusual as many other enzymes involved in the production of catecholamines do. Tryptophan is a poor substrate for tyrosine hydroxylase, however it can hydroxylate L-phenylalanine to form L-tyrosine and small amounts of 3-hydroxyphenylalanine. The enzyme can then further catalyze L-tyrosine to form L-DOPA. Tyrosine hydroxylase may also be involved in other reactions as well, such as oxidizing L-DOPA to form 5-S-cysteinyl-DOPA or other L-DOPA derivatives.
== Early life == Chain was born in Wilmington, Delaware, attended high school at Fork Union Military Academy and was a member of Fork Union Chapter of DeMolay International. He earned a Bachelor of Arts degree in history in 1956 and was awarded an honorary doctorate in humane letters in 1990, both from Denison University. While at Denison University, General Chain was a member of the Sigma Alpha Epsilon fraternity. In 1971 he graduated from the National War College and concurrently earned a master's degree in international affairs from George Washington University.
Absolute specificity can be thought of as being exclusive, in which an enzyme acts upon one specific substrate. Absolute specific enzymes will only catalyze one reaction with its specific substrate. For example, lactase is an enzyme specific for the degradation of lactose into two sugar monosaccharides, glucose and galactose. Another example is Glucokinase, which is an enzyme involved in the phosphorylation of glucose to glucose-6-phosphate. It is primarily active in the liver and is the main isozyme of Hexokinase. Its absolute specificity refers to glucose being the only hexose that is able to be its substrate, as opposed to hexokinase, which accommodates many hexoses as its substrate.
The measurements included one with a range from about 4,250 to about 4,390 years ago, and another with a range from about 4,520 to about 4,690. Errors in procedure can also lead to errors in the results. If 1% of the benzene in a modern reference sample accidentally evaporates, scintillation counting will give a radiocarbon age that is too young by about 80 years.
Sources: en.wikipedia.org
==== Issue of citizenship ==== The report further stated that Russian citizenship, given to the vast part of Abkhaz and Ossetians can not be considered "legally binding under international law" and "the purportedly naturalised persons from South Ossetia and Abkhazia are not Russian nationals in terms of international law." The commission concluded that Abkhaz and South Ossetians legally were citizens of Georgia since 1993, and had not lost their Georgian citizenship at the time of the conflict. The commission also concluded: "The large-scale naturalisations of residents of South Ossetia and Abkhazia with no other factual connection to Russia must be equated to so-called collective (ex lege) naturalisations of foreign residents", which was prohibited. The commission concluded that the creation of Russian citizens in Georgia massively "may be a basis (or rather a pretext) for military intervention", and would amount as a violation of Georgia's sovereignty. The commission concluded that some parts of the Russian Law on Citizenship violated a territorial sovereignty of Georgia. The commission made conclusions that Russian "passportisation" was a meddling in Georgian affairs and demonstrated that Russia was the bad neighbour. The commission stated that humanitarian obstacles caused by Russia to the residents of Abkhazia and South Ossetia "do not justify the large-scale naturalisation of Georgian citizens." The commission stated that "Russia is not allowed under international law to issue passports directly in South Ossetia and Abkhazia, and to pay pensions there".
=== Ligament and tendon repair === Autologous stem cell-based treatments for ligament injury, tendon injury, osteoarthritis, osteochondrosis, and sub-chondral bone cysts have been commercially available to practicing veterinarians to treat horses since 2003 in the United States and since 2006 in the United Kingdom. Autologous stem cell based treatments for tendon injury, ligament injury, and osteoarthritis in dogs have been available to veterinarians in the United States since 2005. Over 3000 privately owned horses and dogs have been treated with autologous adipose-derived stem cells. The efficacy of these treatments has been shown in double-blind clinical trials for dogs with osteoarthritis of the hip and elbow and horses with tendon damage. Race horses are especially prone to injuries of the tendon and ligaments. Conventional therapies are very unsuccessful in returning the horse to full functioning potential. Natural healing, guided by the conventional treatments, leads to the formation of fibrous scar tissue that reduces flexibility and full joint movement. Traditional treatments prevented a large number of horses from returning to full activity and also have a high incidence of re-injury due to the stiff nature of the scarred tendon. Introduction of both bone marrow and adipose derived stem cells, along with natural mechanical stimulus promoted the regeneration of tendon tissue. The natural movement promoted the alignment of the new fibers and tendocytes with the natural alignment found in uninjured tendons.
=== Militant memoirs and propaganda === The Turner Diaries (1978) is a work of fiction, but is confirmed to have inspired terrorist attacks and far-right extremist movements. In the final scene before the epilogue, the main character carries out a suicide attack on The Pentagon, in an aircraft carrying a nuclear bomb.
Sources: en.wikipedia.org
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.
No regulatory agency has approved CJC-1295 for clinical use. Human trials were conducted in the 2000s, but the development programme was discontinued before any marketing application succeeded. Material sold today is offered as a research chemical, and its purity depends on the supplier.
Sermorelin is an unmodified fragment of growth hormone-releasing hormone and is cleared quickly. CJC-1295 contains substitutions that resist breakdown, and the form with a drug affinity complex persists much longer. Both act at the same receptor but differ substantially in duration of action.
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.