If you have been reading about Drug affinity complex and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Physical form | Lyophilized white powder | Supplied as a freeze-dried solid for research use |
| Molecular weight | Approximately 3,647 Da (DAC form) | Lower for the variant lacking the albumin-binding moiety |
| Solubility | Soluble in water and aqueous buffer | Typically dissolved in sterile or bacteriostatic water |
| Typical storage temperature | −20 °C or below | Dry powder, desiccated and protected from light |
| Common analytical method | Reversed-phase HPLC with mass spectrometry | Used for purity estimation and identity confirmation |
Lyophilised powder is the usual supplied form. The material is hygroscopic, so vials are typically equilibrated to room temperature before opening in order to prevent condensation on the contents. Long-term storage is generally described at minus twenty degrees Celsius or colder, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of soluble material. A reconstituted solution is considerably less stable than the dry powder and is normally kept refrigerated for short periods only.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.
Reported half-lives differ widely between the two variants and between species. Values for the albumin-binding form are usually expressed in days, while the unconjugated form is measured in minutes to a few hours. Sampling schedules, assay sensitivity, and route of administration all influence the numbers, which limits direct comparison across studies. Whether sustained receptor occupancy produces different downstream effects from pulsatile stimulation remains an open question in the published work. Claims about relative potency should therefore be read alongside the specific study design that produced them.
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 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
Initially, damage to the brain is regionally specific with the dorsal striatum in the subcortical basal ganglia being primarily affected, followed later by cortical involvement in all areas. Other areas of the basal ganglia affected include the substantia nigra; cortical involvement includes cortical layers 3, 5, and 6; also evident is involvement of the hippocampus, Purkinje cells in the cerebellum, lateral tuberal nuclei of the hypothalamus and parts of the thalamus. These areas are affected according to their structure and the types of neurons they contain, reducing in size as they lose cells. Striatal medium spiny neurons are the most vulnerable, particularly ones with projections towards the external globus pallidus, with interneurons and spiny cells projecting to the internal globus pallidus being less affected. HD also causes an abnormal increase in astrocytes and activation of the brain's immune cells, microglia. The basal ganglia play a key role in movement and behavior control. Their functions are not fully understood, but theories propose that they are part of the cognitive executive system and the motor circuit. The basal ganglia ordinarily inhibit a large number of circuits that generate specific movements. To initiate a particular movement, the cerebral cortex sends a signal to the basal ganglia that causes the inhibition to be released.
Rebellions against Spanish rule had occurred in the empire since the advent of conquest and colonization, but most were either crushed or remained too weak to change the overall situation. The last one that sought outright independence from Spain sprang up around 1810 and culminated in the Colombian Declaration of Independence, issued on 20 July 1810, the day that is now celebrated as the nation's Independence Day. This movement followed the independence of Saint-Domingue (present-day Haiti) in 1804, which provided some support to an eventual leader of this rebellion: Simón Bolívar. Francisco de Paula Santander also would play a decisive role. A movement was initiated by Antonio Nariño, who opposed Spanish centralism and led the opposition against the Viceroyalty. Cartagena became independent in November 1811. In 1811, the United Provinces of New Granada were proclaimed, headed by Camilo Torres Tenorio. The emergence of two distinct ideological currents among the patriots (federalism and centralism) gave rise to a period of instability called the Patria Boba. Shortly after the Napoleonic Wars ended, Ferdinand VII, recently restored to the throne in Spain, unexpectedly decided to send military forces to retake most of northern South America. The viceroyalty was restored under the command of Juan de Sámano, whose regime punished those who participated in the patriotic movements, ignoring the political nuances of the juntas.
Justin McNulty is suspended from the SDLP for leaving the Assembly sitting early to manage Laois GAA at a Gaelic football match in Wexford. Sir Bob Neill, MP for Bromley and Chislehurst, announces he is stand down at the next election to spend more time with his wife, who has suffered a stroke. 4 February – Dafydd Wigley, a former leader of Plaid Cymru, warns that reforms to Wales's political system pose "a very great danger" since it would destroy the relationship between voters and the people they elect. Prime Minister Rishi Sunak arrives in Northern Ireland to visit ministers following the restoration of the Executive. 5 February – Sunak visits Stormont along with Taoiseach Leo Varadkar to mark the restoration of the Northern Ireland Executive. Sunak is criticised by opposition parties after appearing to agree to a £1,000 bet on the Rwanda asylum plan, that the first flight to Rwanda would take off before the election. He subsequently says the challenge, put forward by TalkTV presenter Piers Morgan, took him by surprise, but that it was not a mistake to accept it. Sunak says the government has "not made enough progress" on cutting NHS waiting lists in England, but that industrial action "has had an impact". The UK government sets out its Disability Action Plan, which includes measures to protect people with assistance dogs from being illegally refused entry to businesses. The UK government launches a six-week consultation on plans for Martyn's Law, which would make provisions to better protect the public against potential acts of terrorism.
Sources: en.wikipedia.org
== Molecular Structure of EAATs == Like all glutamate transporters, EAATs are trimers, with each protomer consisting of two domains : the central scaffold domain (Figure 1A, wheat) and the peripheral transport domain (Figure 1A, blue). The transport conformational path is as follows. First, the outward facing conformation occurs (OF, open) which allows the glutamate to bind. Then the HP2 region closes after uptake (OF, closed) and the elevator like movement carries the substrate to the intracellular side of the membrane. It worth nothing that this elevator motion consists of several yet to be categorized/identified conformational changes. After the elevator motion brings the substrate to the IC side of the membrane, EAAT adopts the inward facing (IF, closed) state in which the transport domain is lowered, but the HP2 gate is still closed with the glutamate still bound to the transporter. Lastly, the HP2 gate opens and the glutamate diffuses into the cytoplasm of the cell.
However, the "absolute zero" on the Kelvin temperature scale was originally defined in terms of the second law of thermodynamics, which Thomson himself described in 1852. Thomson did not assume that this was equal to the "zero-volume point" of Charles's law, merely said that Charles's law provided the minimum temperature which could be attained. The two can be shown to be equivalent by Ludwig Boltzmann's statistical view of entropy (1870). However, Charles also stated:
=== Live insect feed === Other insects not killed by farming companies are sold live for consumption by fish and pets. 95% of the Kreca company's insects are sold live. Of the 1500 kg per week of mealworms produced by the Van de Ven company, most are sold as live feed. Live insects may be required for some pets that will not consume dead prey. For instance, monitor lizards are typically fed live insects and may not eat pre-killed ones. It is generally hard to convert reptiles and amphibians that eat insects to pre-killed prey, though some pet owners can feed dead insects by moving or dangling them. For instance, bearded dragons can be fed dead crickets by hiding them in other food, dangling them with tongs, squirting them with water, or vibrating a bowl. Pet spiders, or praying mantids and other insectivorous bugs, typically require live food. Live insects may also be commonly used as fishing bait, with the result that they are either eaten alive by fish or drowned.
Sources: en.wikipedia.org
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.
It has not been approved by major regulatory agencies for any therapeutic indication. Material sold under this name is typically distributed for laboratory research only. Clinical use is not supported by large controlled trials.
Early human studies of the albumin-binding form reported circulation half-lives on the order of several days. The value depends on assay method and study design. Estimates for the form without the binding moiety are considerably shorter.
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.