Drug affinity complex raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-02-12 and is reviewed periodically as new material appears.
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 analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
| 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 |
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.
Diabetes, Obesity and Metabolism is a monthly peer-reviewed medical journal established in 1999 covering research on diabetes, obesity, and metabolism. The journal has a 2024 Clarivate impact factor of 5.7. The journal publishes on topics such as pharmacokinetics and pharmacodynamics, cost-effectiveness, real world evidence of drug utilisation, safety and effectiveness, as well as conventional randomized controlled trials (phase I-IV studies).
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==== A-ring reductases (5alpha- and 5beta-reductases) ==== Cortisol is also metabolized irreversibly into 5-alpha tetrahydrocortisol (5-alpha THF) and 5-beta tetrahydrocortisol (5-beta THF), reactions for which 5-alpha reductase and 5-beta-reductase are the rate-limiting factors, respectively. 5-Beta reductase is also the rate-limiting factor in the conversion of cortisone to tetrahydrocortisone.
Kava is used for medicinal, religious, political, cultural, and social purposes throughout the Pacific. These cultures have a great respect for the plant and place a high importance on it. In Fiji, for example, a formal yaqona (kava) ceremony will often accompany important social, political, or religious functions, usually involving a ritual presentation of the bundled roots as a sevusevu (gift) and drinking of the yaqona itself. Due to the importance of kava in religious rituals and the seemingly (from the Western point of view) unhygienic preparation method, its consumption was discouraged or even banned by Christian missionaries. The nakamal, traditionally the central meeting place in Vanuatu, serves as a cultural and social hub where kava is consumed to facilitate communal gathering, dialogue, and the exchange of knowledge across different groups and generations.
Reform UK removes Ian Cooper, leader of Staffordshire County Council, from the party following an investigation into online racist comments. 6 December – It is announced that transgender women will not be allowed to take part in the main event of the 2026 Labour Women's Conference. Former Conservative minister and peer Malcolm Offord defects to Reform UK, and says he will stand down from the House of Lords to campaign in the 2026 Scottish Parliament election. 7 December – Prime Minister Keir Starmer says that Angela Rayner will return to the cabinet, describing her as "hugely talented". 8 December – Essex Police are investigating allegations made by a former Reform UK councillor that the party overspent while campaigning in the Clacton constituency during the 2024 general election. Reform UK selects Addy Mo Asaduzzaman, a Bangladeshi with indefinite leave to remain in the UK, to stand in Central Southsea at local elections in May 2026. The announcement leads to criticism of the party. 9 December – Home Secretary Shabana Mahmood announces that former Children's Commissioner Baroness Anne Longfield will lead the inquiry into grooming gangs. Thirteen Labour MPs back a Liberal Democrat bill requiring the government to begin negotiations on joining a bespoke customs union with the EU, leading to a tied vote of 100–100. In her capacity as holder of the deciding vote Deputy Speaker Caroline Noakes gives her backing to the bill, allowing for it to have further debate. Ian Cooper resigns as leader of Staffordshire County Council after he was expelled by Reform UK.
== Medical uses == Medications based on incretins are used in the treatment of type 2 diabetes mellitus as well as the management of obesity. Most of the earliest incretin-targeting agents to be approved fell into the class of DPP-4 inhibitors; these inhibit DPP-4 and prevent the enzymatic degradation of GLP-1 and GIP. The first medication in this class, sitagliptin, received FDA approval in 2006 for the treatment of type 2 diabetes. GLP-1 analogs principally act as agonists of the GLP-1 receptor and are thus insulinotropic. Exenatide was the first drug in this class to be used in the treatment of type 2 diabetes; it received FDA approval in 2005. More recently, longer-acting and more potent GLP-1 analogs have been developed, most notably semaglutide, which received FDA approval for type 2 diabetes in 2017. It was subsequently approved for the management of obesity. In 2021, it was in the Top 100 most-prescribed drugs in the United States. Tirzepatide (sold as Mounjaro and Zepbound) is a potent GIP analog with agonist activity at GIP and GLP-1 receptors. It was approved for the treatment of type 2 diabetes in the United States in May 2022, and for the management of obesity in November 2023.
Sources: en.wikipedia.org
9 November – Buckingham Palace announces that Queen Camilla will miss Remembrance events held over the weekend as she recovers from a chest infection. 10 November – First Minister of Northern Ireland Michelle O'Neill becomes the first senior Sinn Féin figure to take part in an official Remembrance Sunday ceremony, held in Belfast. 11 November The Terminally Ill Adults (End of Life) Bill, which would allow terminally ill people in England and Wales with less than six months to live to seek assistance in ending their lives, with the consent of two doctors and a High Court judge, is published. Helen-Ann Hartley, the Bishop of Newcastle, calls for Justin Welby to resign as the Archbishop of Canterbury following a damning report into prolific child abuser John Smyth QC, who was associated with the Church of England. At the Old Bailey, former soldier Daniel Khalife changes his plea midway through his trial, and pleads guilty to escaping from prison in September 2023. His trial on three other charges continues. At the invitation of French President Emmanuel Macron, Starmer travels to France to mark Armistice Day at the Tomb of the Unknown Soldier, then holds talks with Macron to affirm the UK and France's commitment to supporting Ukraine. 12 November The BBC confirms that Gary Lineker will step down as Match of the Day presenter at the end of the current season, but will host BBC Sport's coverage of the 2026 World Cup.
Needle aspiration biopsy, via needle Surgically, via an incision made into the tumor A pathologist examines the tissue under a microscope. The pathologist may be the most important person in the treatment of sarcomas, because they are responsible for making the proper diagnosis. Pathologists at expert sarcoma centers are invaluable in identifying the type of sarcoma responsible for a patient's symptoms. If cancer is present, the pathologist can usually determine the type of cancer and its grade. Here, grade refers to a scale used to represent concisely the predicted growth rate of the tumor and its tendency to spread, and this is determined by the degree to which the cancer cells appear abnormal when examined under a microscope. Low-grade sarcomas, although cancerous, are defined as those that are less likely to metastasise. High-grade sarcomas are defined as those more likely to spread to other parts of the body. For soft-tissue sarcoma, the two histological grading systems are the National Cancer Institute system and the French Federation of Cancer Centers Sarcoma Group system. Soft-tissue sarcomas commonly originate in the upper body, in the shoulder or upper chest. Some symptoms are uneven posture, pain in the trapezius muscle, and cervical inflexibility [difficulty in turning the head]. The most common site to which soft-tissue sarcoma spreads is the lungs.
The species was first described by Elias Magnus Fries as Agaricus semilanceatus in his 1838 work Epicrisis Systematis Mycologici. Paul Kummer transferred it to Psilocybe in 1871 when he raised many of Fries's sub-groupings of Agaricus to the level of genus. Panaeolus semilanceatus, named by Jakob Emanuel Lange in both 1936 and 1939 publications, is a synonym. According to the taxonomical database MycoBank, several taxa once considered varieties of P. semilanceata to be synonymous with the species now known as Psilocybe strictipes: the caerulescens variety described by Pier Andrea Saccardo in 1887 (originally named Agaricus semilanceatus var. coerulescens by Mordecai Cubitt Cooke in 1881), the microspora variety described by Rolf Singer in 1969, and the obtusata variety described by Marcel Bon in 1985. Several molecular studies published in the 2000s demonstrated that Psilocybe, as it was defined then, was polyphyletic. The studies supported the idea of dividing the genus into two clades, one consisting of the bluing, hallucinogenic species in the family Hymenogastraceae, and the other the non-bluing, non-hallucinogenic species in the family Strophariaceae. However, the generally accepted lectotype (a specimen later selected when the original author of a taxon name did not designate a type) of the genus as a whole was Psilocybe montana, which is a non-bluing, non-hallucinogenic species. If the non-bluing, non-hallucinogenic species in the study were to be segregated, it would have left the hallucinogenic clade without a valid name.
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.
The two share the same 29-amino-acid backbone. CJC-1295 carries an additional albumin-binding moiety that markedly extends its residence time in circulation, while the form without that moiety clears faster. Literature sometimes applies the name loosely to either variant.