DAC is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-06-02. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
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.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
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.
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.
=== Immune system === Immune cells of both the innate immune system and adaptive immune systems frequently express the α2, α5, α6, α7, α9, and α10 subunits of nicotinic acetylcholine receptors. Evidence suggests that nicotinic receptors which contain these subunits are involved in the regulation of immune function. Although some of its effects are pro-inflammatory (e.g., inducing prostaglandin E2 production), nicotine effects are mostly anti-inflammatory. Nicotine suppresses the innate and adaptive immune response by reducing the secretion of pro-inflammatory cytokines (IL-1, IL-6, TNF-α, IL-17, IL-21, and IL-22), reducing proliferation and activation of T-cells, and suppressing the activation of dendritic cells. As a result, cell-mediated immunity against infection and neoplastic diseases is downregulated. In vitro and animal studies also showed that nicotine reduces T cell receptor (TCR) signaling and suppresses the production and secretion of antibodies. Nicotine effects on immune system function can aggravate tumors (growth and metastases) in cancer patients and is found to have many positive effects in the treating autoimmune disease (e.g. inflammatory bowel disease/ulcerative colitis, arthritis), requiring further studies.
A burn is an injury to skin, or other tissues, caused by heat, electricity, chemicals, friction, or ionizing radiation (such as sunburn, caused by ultraviolet radiation). Most burns are thermal burns caused by contact with heat from hot fluids (called scalding), solids, or fire. Burns occur mainly in the home or the workplace. In the home, risks are associated with domestic kitchens, including stoves, flames, and hot liquids. In the workplace, risks are associated with fire and chemical and electric burns. Alcoholism and smoking are other risk factors. Burns can also occur as a result of self-harm or violence between people (assault). Burns that affect only the superficial skin layers are known as superficial or first-degree burns. They appear red without blisters, and pain typically lasts around three days. When the injury extends into some of the underlying skin layer, it is a partial-thickness or second-degree burn. Blisters are frequently present and they are often very painful. Healing can require up to eight weeks and scarring may occur. In a full-thickness or third-degree burn, the injury extends to all layers of the skin. Often there is no pain and the burnt area is stiff. Healing typically does not occur on its own. A fourth-degree burn additionally involves injury to deeper tissues, such as muscle, tendons, or bone. The burn is often black and frequently leads to loss of the burned part. Burns are generally preventable. Treatment depends on the severity of the burn.
Although Descartes agreed with the contemporary position, that a vacuum does not occur in nature, the success of his namesake coordinate system and more implicitly, the spatial–corporeal component of his metaphysics would come to define the philosophically modern notion of empty space as a quantified extension of volume. By the ancient definition however, directional information and magnitude were conceptually distinct.
Elton John plays the final UK concert of his farewell tour at Glastonbury 2023, headlining the Pyramid Stage on the festival's final day. 26 June A two-year BBC investigation into the 1993 murder of Stephen Lawrence identifies a sixth suspect who was not charged at the time and is now deceased. Banking giant HSBC announces that it will vacate its 45-storey tower at 8 Canada Square in Canary Wharf and establish a smaller headquarters, possibly in the City of London, when its current lease expires in 2027. The move is attributed to an increase in remote work and less need for in-person office work. Prince William and Geri Horner announce the launch of Homewards, a five-year project aimed at reducing the number of homeless people in the UK. The National Cancer Research Institute announces that it will be closing, amid concerns over its funding. 27 June Boots announces plans to close 300 of its outlets over the next years, saying it will close stores in close proximity to other branches. A report compiled by the Independent Commission for Equity in Cricket (ICEC) says racism, sexism, classism and elitism are "widespread" in English and Welsh cricket. 28 June Daniel Korski withdraws as the Conservative Party's candidate for the 2024 London mayoral election after being accused of groping by novelist and TV producer Daisy Goodwin. A BBC News investigation finds that paedophiles are using Stable Diffusion, a piece of artificial intelligence software, to create lifelike images of child sexual abuse, which are then being distributed through platforms such as Patreon.
Sources: en.wikipedia.org
=== High-altitude radiation === In 1912, Victor Franz Hess (1883-1964) discovered (secondary) cosmic rays in the Earth's atmosphere using balloon flights. For this discovery he received the Nobel Prize in Physics in 1936. He was also one of the "martyrs" of early radiation research and had to undergo a thumb amputation and larynx surgery due to radium burns. In the United States and the Soviet Union, balloon flights to altitudes of about 30 km, followed by parachute jumps from the stratosphere, were conducted before 1960 to study human exposure to cosmic radiation in space. The American Manhigh and Excelsior projects with Joseph Kittinger (1928-2022) became particularly well known, but the Soviet parachutist Yevgeny Andreyev (1926-2000) also set new records.
Parmotrema perlatum is used as a spice, particularly in the cuisine of Tamil Nadu. It is especially prevalent in Chettinad cuisine, being used in the popular rice dish biryani, and also in many meat and vegetarian dishes. In its raw state, black stone flower does not have much taste or fragrance. However, when put in contact with heat, especially hot cooking oil or ghee, it releases a distinctive earthy, smoky flavour and aroma. This property of black stone flower is especially valued in the tempering step of cooking a number of Indian dishes. The spice is also integral to various regional masalas throughout the Indian subcontinent. Parmotrema perlatum is a key ingredient in masalas such as Kala and Goda masala of Maharashtra, Anglo-Indian bottle masala, bhojwar masala from Hyderabad, and potli masala in Lucknow. It is what many cooks and commercial spice blend makers believe sets apart accomplished dishes from those made by amateurs. Despite its lack of a specific aroma or describable flavour in its raw form, its contribution to the complex flavour profile of these spice blends is highly valued.
Cape Town ⟷ Kimberley ⟷ Johannesburg: General freight Durban ⟷ Richards Bay: Coastal freight Johannesburg ⟷ Durban: General freight (SA's busiest intermodal freight corridor) Johannesburg ⟷ Gqeberha / Ngqura: Automotive exports and manufactured goods Johannesburg ⟷ Polokwane: Mining supplies, and agricultural and manufacturing freight Johannesburg ⟷ Richards Bay: General freight Johannesburg ⟷ KuGompo City: Automotive and general freight Johannesburg ⟷ Komatipoort: Cross-border freight to Mozambique and the rest of the SADC Johannesburg ⟷ Beitbridge: Cross-border freight into Zimbabwe Johannesburg ⟷ Mahikeng / Ramatlabama: Cross-border freight into Botswana As of 2026, Transnet Freight Rail moves 17% of South Africa's freight annually, including 100% of its export coal and iron ore. The company coordinates its rail freight services with other Transnet divisions, such as ports, pipelines, and engineering. With over 25,000 employees, Transnet Freight Rail generates over R14 billion in annual revenue. For its 2025/2026 financial year, Transnet expected to transport a total rail cargo volume of around 168 million tons, up around 5%, from 160.1 million tons the year before. Under the South African Government's rail restructuring plan, the goal is for Transnet to reach a transport capacity of 185 million tons, with a further 65 million tons transported by private operators, by 2030. This would make for a total South African cargo rail capacity of 250 million tons per year.
Sources: en.wikipedia.org
==== Multiple bodies per grave ==== Some couples or groups of people (such as a married couple or other family members) may wish to be buried in the same plot. In some cases, the coffins (or urns) may simply be buried side by side. In others, one casket may be interred above another. If this is planned for in advance, the first casket may be buried more deeply than is the usual practice so that the second casket may be placed over it without disturbing the first. In many states in Australia all graves are designated two or three depth (depending on the water table) for multiple burials, at the discretion of the burial rights holder, with each new interment atop the previous coffin separated by a thin layer of earth. As such all graves are dug to greater depth for the initial burial than the traditional six feet to facilitate this practice. Mass burial is the practice of burying multiple bodies in one location. Civilizations attempting genocide often employ mass burial for victims. However, mass burial may in many cases be the only practical means of dealing with an overwhelming number of human remains, such as those resulting from a natural disaster, an act of terrorism, an epidemic, or an accident. This practice has become less common in the developed world with the advent of genetic testing, but even in the 21st century remains which are unidentifiable by current methods may be buried in a mass grave. Individuals who are buried at the expense of the local authorities and buried in potter's fields may be buried in mass graves.
For his appearance on the heavily collaborative track "Back on the Block", a composition by jazz musician Quincy Jones that "attempt[ed] to bring together black musical styles from jazz to soul to funk to rap", Ice-T won a Grammy Award for the Best Rap Performance by a Duo or Group, an award shared by others who worked on the track including Jones and fellow jazz musician Ray Charles. Controversy later surrounded Body Count over its song "Cop Killer". The rock song was intended to speak from the viewpoint of a criminal getting revenge on racist, brutal cops. Ice-T's rock song infuriated government officials, the National Rifle Association of America, and various police advocacy groups. Consequently, Time Warner Music refused to release Ice-T's upcoming album Home Invasion because of the controversy surrounding "Cop Killer". Ice-T suggested that the furor over the song was an overreaction, telling journalist Chuck Philips "...they've done movies about nurse killers and teacher killers and student killers. Arnold Schwarzenegger blew away dozens of cops as the Terminator. But I don't hear anybody complaining about that". In the same interview, Ice-T suggested to Philips that the misunderstanding of Cop Killer, the misclassification of it as a rap song (not a rock song), and the attempts to censor it had racial overtones: "The Supreme Court says it's OK for a white man to burn a cross in public. But nobody wants a black man to write a record about a cop killer". Ice-T split amicably with Sire/Warner Bros. Records after a dispute over the artwork of the album Home Invasion.
Ghosh SK, Paik WK, Kim S (1988). "Purification and molecular identification of two protein methylases I from calf brain. Myelin basic protein- and histone-specific enzyme". J. Biol. Chem. 263 (35): 19024–33. doi:10.1016/S0021-9258(18)37384-8. PMID 2461933.
Sources: en.wikipedia.org
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.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
It is a synthetic peptide modeled on growth hormone-releasing hormone. The molecule is used in research on pituitary growth hormone secretion. It differs from the natural hormone through several stabilizing substitutions.