DAC raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-15. Anything still debated is marked as such rather than presented as settled.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (with DAC) | ~3647 Da | Calculated from the full amino acid sequence |
| Molecular weight (without DAC) | ~3368 Da | Mod GRF(1-29) variant |
| Appearance | White lyophilized powder | Typical form supplied for research |
| Solubility | Soluble in water | Dissolves in aqueous buffers |
| Receptor target | GHRH receptor | Expressed on pituitary somatotroph cells |
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.
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.
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.
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.
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 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.
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.
Beta-peptides (β-peptides) are peptides derived from β-amino acids, in which the amino group is attached to the β-carbon (i.e. the carbon two atoms away from the carboxylate group). The parent β-amino acid is β-alanine (H2NCH2CH2CO2H), a common natural substance, but most examples feature substituents in place of one or more C-H bonds. β-peptides usually do not occur in nature. β-Peptide-based antibiotics are being explored as ways of evading antibiotic resistance. Early studies in this field were published in 1996 by the group of Dieter Seebach and that of Samuel Gellman.
People who intravenously inject black tar heroin are at higher risk of venous sclerosis than those injecting powder heroin. In this condition, the veins narrow and harden which makes repeated injection there nearly impossible. The presence of 6-monoacetylcodeine found in tar heroin has not been tested in humans but has been shown to be toxic alone and more toxic when mixed with mono- or di- acetyl morphine, potentially making tar more toxic than refined diamorphine. Black tar heroin injectors can be at increased risk of life-threatening bacterial infections, in particular necrotizing soft tissue infection. The practice of "skin-popping" or subcutaneous injection predisposes to necrotizing fasciitis or necrotizing cellulitis from Clostridium perfringens, while deep intramuscular injection predisposes to necrotizing myositis. Tar heroin injection can also be associated with Clostridium botulinum infection, causing botulism. Since the final stage of black tar heroin production would kill any spores (a combination of high temperature and strong acid), contamination is likely due to choice of cutting agent. Almost all cases occur in users who inject intramuscularly or subcutaneously, rather than injecting intravenously. Black tar heroin users can also be at increased risk of bone and joint infections that stem from hematogenous seeding or local extension of the skin and soft tissue infections. Any joint can be infected, though previous studies have shown that the knee and hip are most commonly affected in heroin injectors.
== Toxicity == Azacitidine causes anemia (low red blood cell counts), neutropenia (low white blood cell counts), and thrombocytopenia (low platelet counts), and patients should have frequent monitoring of their complete blood counts, at least prior to each dosing cycle. The dose may have to be adjusted based on nadir counts and hematologic response. It can also be hepatotoxic in patients with severe liver impairment, and patients with extensive liver tumors due to metastatic disease have developed progressive hepatic coma and death during azacitidine treatment, especially when their albumin levels are less than 30 g/L. It is contraindicated in patients with advanced malignant hepatic tumors. Kidney toxicity, ranging from elevated serum creatinine to kidney failure and death, have been reported in patients treated with intravenous azacitidine in combination with other chemotherapeutic agents for conditions other than myelodysplastic syndrome. Renal tubular acidosis developed in five patients with chronic myelogenous leukemia (an unapproved use) treated with azacitidine and etoposide, and patients with renal impairment may be at increased risk for renal toxicity. Azacitidine and its metabolites are primarily excreted by the kidneys, so patients with chronic kidney disease should be closely monitored for other side effects, since their levels of azacitidine may progressively increase. Based on animal studies and its mechanism of action, azacitidine can cause severe fetal damage.
Flower preservation has existed since early history, although deliberate flower preservation is a more recent phenomenon. In the Middle East, the bones of pre-historic man were discovered with delicate wild flowers probably as a tribute to a passing loved one. Evidence of deliberate use of specific flowers is indicated by the pollen grains that were present. Brightly colored and vivid flowers were also found in Egyptian tombs. These flowers were approximated to be 4,000 years old. In the sixteenth century medicinal nosegays began to give way to ornamental ones. Flowers essentially started to be used for decorative purposes such as jewels, fans and gloves. During the Elizabethan Age the once familiar ruff was replaced by soft lacy collars, and bosom flowers also became popular.
Sources: en.wikipedia.org
In 2024, the government looked into legalising these services.Bus services operate more than 700 routes across the territory, with smaller public light buses (also known as minibuses) serving areas standard buses do not reach as frequently or directly. Expressways and truck roads, organised with the Hong Kong Strategic Route and Exit Number System, connect all major areas of the territory. The Hong Kong–Zhuhai–Macau Bridge provides a direct route to the western side of the Pearl River estuary.
Bromantane, sold under the brand name Ladasten, is an atypical central nervous system (CNS) stimulant and anxiolytic drug of the adamantane family that is related to amantadine and memantine. Medically, it is approved in Russia for the treatment of neurasthenia. Although the effects of bromantane have been determined to be dependent on the dopaminergic and possibly serotonergic neurotransmitter systems, its exact mechanism of action is unknown, and is distinct in its properties relative to typical stimulants such as amphetamine. Bromantane has sometimes been described as an actoprotector (synthetic adaptogen).
== General and cited references == Hartwig, Andrea (2013). "Cadmium and Cancer". Cadmium: From Toxicity to Essentiality. Metal Ions in Life Sciences. Vol. 11. pp. 491–507. doi:10.1007/978-94-007-5179-8_15. ISBN 978-94-007-5178-1. PMID 23430782. "Cadmium and you" (PDF). Bootle, UK: Health and Safety Executive. March 2010. Retrieved January 29, 2011. Shannon M. "Heavy Metal Poisoning", in Haddad LM, Shannon M, Winchester JF (editors): Clinical Management of Poisoning and Drug Overdose, Third Edition, 1998.
Sources: en.wikipedia.org
=== Prewar and postwar eras === The club came close to reaching the First Division in their early years. In the 1921–22 season, they missed out on promotion by goal difference. During the 1930s and 1940s years, the club found themselves sliding between the Second and Third Division. In 1949, the club signed Danny Blanchflower from Glentoran, and he impressed at Oakwell that two years later he was signed by First Division side Aston Villa, later signing for Tottenham Hotspur and being voted FWA Player of the Year twice, as well as being the captain of the 20th century's first league and cup double winning team in 1960–61. Around the time of Blanchflower's departure, a young centre-forward called Tommy Taylor broke into the Barnsley team, scoring 26 goals in 44 games. In April 1953, he became one of the most expensive players in English football at the time when Sir Matt Busby signed him for Manchester United for a fee of £29,999. Taylor went on to be a prolific goalscorer at the highest level over the next five years, winning two league titles and scoring 16 goals in 19 appearances for the England national football team, before losing his life in the Munich air disaster on 6 February 1958. When the Northern and Southern sections of the Third Division were replaced by national Third and Fourth Divisions for the 1958–59 season, Barnsley were still in the Second Division, but went down to the Third Division at the end of the season. In 1965, Barnsley were relegated to the Football League Fourth Division for the first time, winning promotion three years later.
Dalbergia odorifera, fragrant rosewood or Chinese rosewood, is a species of true rosewood in the genus Dalbergia. It is a small or medium-sized tree, 10–15 metres (33–49 ft) tall. It is endemic to China and occurs in Fujian, Hainan, Zhejiang, and Guangdong.
== Disaccharide phosphorylases == Different biocatalytic approaches have been developed toward the synthesis of glycosides in past decades, for which glycosyltransferases and glycoside hydrolases are among the most common catalysts. The former often needs expensive materials and the latter often shows low yields. De Winter et al. investigated use of cellobiose phosphorylase (CP) toward synthesis of alpha-glycosides in ionic liquids. The best condition for use of CP was found to be in the presence of the ionic liquid AMMOENG 101 and ethyl acetate.
== Cited sources == Martin, Archer J. P. (December 12, 1952). "The development of partition chromatography. Nobel Lecture" (PDF). Nobel Lectures, Chemistry 1942–1962. Amsterdam: Elsevier. Ettre, Leslie Stephen (2001). "The Predawn of Paper Chromatography". Chromatographia. 54 (5–6): 409–414. doi:10.1007/BF02492694. S2CID 95357195. Touchstone, Joseph C. (1993). "History of Chromatography". Journal of Liquid Chromatography. 16 (8): 1647–1665. doi:10.1080/10826079308021679.
Sources: en.wikipedia.org
The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.
The maleimide group forms a covalent link with albumin, an abundant blood protein. This attachment slows clearance, so a single administration persists much longer than the unmodified peptide. The feature is the main reason the two variants are handled differently in study design.
It is not an approved therapeutic product in major regulatory jurisdictions. It appears in research chemical catalogs and scientific literature rather than pharmacy shelves. Clinical development was limited and did not reach approval.
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.