If you have been reading about DAC linker 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 2026-03-17. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
| 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 |
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
At the pituitary, the peptide binds the growth hormone-releasing hormone receptor on somatotroph cells. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone. Somatostatin and other hypothalamic signals modulate this response. Negative feedback from insulin-like growth factor 1 also influences output. The same regulatory architecture operates with the native hormone. Whether the synthetic analog alters feedback dynamics over repeated exposure remains an open question. Most published receptor work uses cell models rather than intact human systems.
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.
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 includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
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.
On January 31, 1958, nearly four months after the launch of Sputnik 1, aerospace and space engineer, Dr. Wernher von Braun and the United States successfully launched its first satellite on a four-stage Juno I rocket derived from the US Army's Redstone missile, at Cape Canaveral. The satellite Explorer 1 was 30.66 pounds (13.91 kg) in mass. The payload of Explorer 1 weighed 18.35 pounds (8.32 kg). It carried a micrometeorite gauge and a Geiger–Müller tube. It passed in and out of the Earth-encompassing radiation belt with its 194-by-1,368-nautical-mile (360 by 2,534 km) orbit, therefore saturating the tube's capacity and proving what Dr. James Van Allen, a space scientist at the University of Iowa, had theorized. The belt, named the Van Allen radiation belt, is a doughnut-shaped zone of high-level radiation intensity around the Earth above the magnetic equator. Van Allen was also the man who designed and built the satellite instrumentation of Explorer 1. The satellite measured three phenomena: cosmic ray and radiation levels, the temperature in the spacecraft, and the frequency of collisions with micrometeorites. The satellite had no memory for data storage, therefore it had to transmit continuously. The next successful mission was Explorer 3, launched later that month (March 26, 1958), which carried similar scientific instruments and successfully recorded cosmic ray data.
== Urban hydroponics == Urban hydroponics refers to the use of soilless cultivation systems in city environments, including apartments, rooftops, and other indoor spaces. These systems have been explored in response to challenges related to urban food access. According to the United States Department of Agriculture, more than 19 million people in the United States live in low-income neighborhoods with limited access to supermarkets or large grocery stores, areas often referred to as food deserts. In these contexts, hydroponic systems can be used as a method to grow vegetables such as lettuce, spinach, and herbs indoors. Urban hydroponic systems are generally designed to operate within small spaces. Commercially available units include vertical towers, countertop kits, and window-mounted structures, many of which rely on artificial lighting and water circulation to deliver nutrients directly to plant roots. These configurations are intended to support plant growth in environments with limited natural sunlight and no access to soil. Some hydroponic systems are marketed toward individual consumers and households. While larger systems may require significant investment, smaller-scale models are available for individual use. Reports suggest that such systems can produce a range of crops year-round, though yield and cost-efficiency vary by setup and user experience. Hydroponic systems have also been studied for their resource efficiency.
=== Physical intervention === The most widely used therapeutic intervention is positive airway pressure whereby a breathing machine pumps a controlled stream of air through a mask worn over the nose, mouth, or both. The additional pressure holds open the relaxed muscles. There are several variants:
== Treatment == SJS constitutes a dermatological emergency. Patients with documented Mycoplasma infections can be treated with oral macrolide or oral doxycycline. Initially, treatment is similar to that for patients with thermal burns, and continued care can only be supportive (e.g., intravenous fluids and nasogastric or parenteral feeding) and symptomatic (e.g., analgesic mouth rinse for mouth ulcer). Dermatologists and surgeons tend to disagree about whether the skin should be debrided. Beyond this kind of supportive care, no treatment for SJS is accepted. Treatment with corticosteroids is controversial. Early retrospective studies suggested corticosteroids increased hospital stays and complication rates. No randomized trials of corticosteroids have been conducted for SJS, and it can be managed successfully without them. Other agents have been used, including cyclophosphamide and ciclosporin, but none have exhibited much therapeutic success. Intravenous immunoglobulin treatment has shown some promise in reducing the length of the reaction and improving symptoms. Other common supportive measures include the use of topical pain anesthetics and antiseptics, maintaining a warm environment, and intravenous analgesics. An ophthalmologist should be consulted immediately, as SJS frequently causes the formation of scar tissue inside the eyelids, leading to corneal vascularization, impaired vision, and a host of other ocular problems.
=== Receptor interaction === After being released into the synaptic cleft, neurotransmitters diffuse across the synapse where they are able to interact with receptors on the target cell. The effect of the neurotransmitter is dependent on the identity of the target cell's receptors present at the synapse. Depending on the receptor, binding of neurotransmitters may cause excitation, inhibition, or modulation of the postsynaptic neuron.
Sources: en.wikipedia.org
=== Genetic influence and environmental factors === Various studies have found direct genetic effects to account for at least 46% of the variation of timing of puberty in well-nourished populations. The genetic association of timing is strongest between mothers and daughters. The specific genes affecting timing are not yet known. Among the candidates is an androgen receptor gene. Researchers have hypothesized that early puberty onset may be caused by certain hair care products containing estrogen or placenta, and by certain chemicals, namely phthalates, which are used in many cosmetics, toys, and plastic food containers.
=== Attitudes towards the US === Trump's threats have been described by Le Monde as turning the Greenlanders decidedly against the US. While Greenland is a longtime ally of the US with a traditionally positive view of the country, the view of the US has become strongly negative as a result of Trump's behaviour.
=== Cancer === Macrophages can contribute to tumor growth and progression by promoting tumor cell proliferation and invasion, fostering tumor angiogenesis and suppressing antitumor immune cells. Inflammatory compounds, such as tumor necrosis factor (TNF)-alpha released by the macrophages activate the gene switch nuclear factor-kappa B. NF-κB then enters the nucleus of a tumor cell and turns on production of proteins that stop apoptosis and promote cell proliferation and inflammation. Moreover, macrophages serve as a source for many pro-angiogenic factors including vascular endothelial factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), macrophage colony-stimulating factor (M-CSF/CSF1) and IL-1 and IL-6, contributing further to the tumor growth. Macrophages have been shown to infiltrate a number of tumors. Their number correlates with poor prognosis in certain cancers, including cancers of breast, cervix, bladder, brain and prostate. Some tumors can also produce factors, including M-CSF/CSF1, MCP-1/CCL2 and Angiotensin II, that trigger the amplification and mobilization of macrophages in tumors. Additionally, subcapsular sinus macrophages in tumor-draining lymph nodes can suppress cancer progression by containing the spread of tumor-derived materials.
Lipoic acid (LA), also known as α-lipoic acid, alpha-lipoic acid (ALA) and thioctic acid, is an organosulfur compound derived from caprylic acid (octanoic acid). ALA, which is made in animals normally, is essential for aerobic metabolism. It is also available as a dietary supplement or pharmaceutical drug in some countries. Lipoate is the conjugate base of lipoic acid, and the most prevalent form of LA under physiological conditions. Only the (R)-(+)-enantiomer (RLA) exists in nature. RLA is an essential cofactor of many processes.
Sources: en.wikipedia.org
Modelled after Umkhonto we Sizwe, the armed wing of the African National Congress, the South West African Liberation Army (SWALA) was formed by SWAPO in 1962. The first seven SWALA recruits were sent from Dar es Salaam to Egypt and the Soviet Union, where they received military instruction. Upon their return, they began training guerrillas at a makeshift camp established for housing South West African refugees in Kongwa, Tanzania.
=== June 2006 === According to the Iraqi Defense Ministry, Private First Class Thomas Tucker and Private First Class Kristian Menchaca were reportedly "killed in a barbaric way," "slaughtered," and tortured to death, and their bodies were so mutilated that DNA tests are being performed to help identify their remains. The alleged group has said it was a revenge for the rape and murder of an Iraqi girl who was dishonoured by soldiers of the same brigade. Video of the killing of four Russian diplomats kidnapped in Iraq appear on the Internet. A group called the Mujahideen Shura Council released the hostage video.
=== Recreational use === Over-the-counter pseudoephedrine has been misused as a psychostimulant. Six case reports and one case series of pseudoephedrine misuse have been published as of 2021. There is a case report of self-medication with pseudoephedrine for treatment of depression.
== Trump's letter to Khamenei == On March 7, 2025, Trump announced that he had written a letter to Ali Khamenei, expressing his desire to initiate new nuclear negotiations with Iran. He warned that failure to accept the proposal could expose Iran to serious military consequences. Trump also imposed additional sanctions on the country and pledged to reduce Iran's oil exports to zero. According to Emirati political scientist Abdulkhaleq Abdullah, the letter included demands that Iran fully dismantle its nuclear program, halt all enrichment, and end support for regional proxy groups, with compliance required within two months. In exchange, the US offered to lift sanctions and normalize relations, while warning that failure to negotiate would result in military strikes. Initially, Khamenei did not acknowledge the letter, indicating that Iran would not meet the new expectations. During March 2025, Iran and the US engaged in indirect exchanges over Trump's letter, with both sides issuing threats. Khamenei reportedly changed his mind about the negotiations after his advisors warned that the threat of war with the United States and the deepening economic crisis could bring down the government. By the end of March, the Iranian leadership had sent a reply to the letter expressing readiness for nuclear negotiations.
Recent discoveries made through use of high-throughput 'omics approaches include the fact that AAV capsids are post-translationally modified (PTM) during production such as acetylation, methylation, phosphorylation, deamidation, O-GlycNAcylation and SUMOylation throughout capsid proteins VP1, VP2 and VP3. These PTMs differ depending on the manufacturing production platform. Another such discovery is the fact that AAV genomes are epigenetically methylated during production. Besides price, these findings might affect expression kinetics, rAAV receptor binding, trafficking, vector immunogenicity, and expression durability.
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.
Natural GHRH is degraded quickly by dipeptidyl peptidase-4 and related enzymes, giving it a half-life measured in minutes. CJC-1295 carries substitutions that slow that breakdown, so it stays intact longer. Both act at the same pituitary receptor and produce the same class of signal.