A practical reference on DAC group: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-02. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
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.
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.
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.
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.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
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.
Such patients suffer both diaphragm atrophy (the weakening of the muscles that allow one to inhale and exhale, which atrophy dangerously due to disuse during time on a ventilator) and critical illness myopathy (the broad weakening of the muscles during extended bed rest). Each of these conditions are associated with poor functional recovery and substantially increased risk of death after illness.
== Biology and genetics == S. boulardii was originally described as a species distinct from S. cerevisiae based on phenotypic traits, including the inability to ferment galactose, a reported lack of sporulation under standard laboratory conditions, and increased tolerance to human body temperature, gastric acidity, and digestive enzymes compared with many S. cerevisiae strains. Subsequent molecular and genomic analyses, however, have shown that S. boulardii falls within the genetic diversity of S. cerevisiae, forming a distinct clade most closely related to wine-associated strains. Like other S. cerevisiae strains, S. boulardii possesses 16 nuclear chromosomes and a 2-micron plasmid, and is diploid, carrying genetic determinants for both mating types (MATa and MATα). However, the MATa locus in S. boulardii contains mutations predicted to impair mating and sporulation, which may account for its reduced or absent sporulation phenotype under laboratory conditions. S. boulardii shares with other S. cerevisiae strains the production of secreted proteins reported to interfere with certain bacterial pathogens and their toxins, including a 63-kDa phosphatase (Pho8) that reduces Escherichia coli endotoxin activity and a 54-kDa serine protease (Ysp3) capable of degrading Clostridioides difficile toxins A and B. An additional, as-yet-unidentified protein of approximately 120 kDa has been reported to inhibit cholera toxin–induced increases in intracellular cyclic AMP (cAMP).
According to Harvard Professor Kenneth Rogoff as of 2025, bitcoin is rarely used in regular transactions with merchants, but is popular in the informal economy and for criminal activities. Prices are not usually quoted in bitcoin and trades involve conversions into fiat currencies. Commonly cited reasons for not using bitcoin include high costs, the inability to process chargebacks, high price volatility, long transaction times, and transaction fees (especially for small purchases). Bloomberg reported that bitcoin was being used for large-item purchases on the site Overstock.com and for cross-border payments to freelancers. As of 2015, there was little sign of bitcoin use in international remittances despite high fees charged by banks and Western Union. From September 2021 until January 2025, the Bitcoin Law made bitcoin a legal tender currency in El Salvador, alongside the US dollar. The adoption had been criticized internationally and within El Salvador. In 2022, the International Monetary Fund (IMF) urged El Salvador to reverse its decision. As of 2022, the use of Bitcoin in El Salvador remained low: 80% of businesses refused to accept it. In 2025, El Salvador's government revoked bitcoin's status as legal tender currency to comply with conditions set by the IMF for a loan. El Salvador still describes bitcoin as "legal tender", but its acceptance is no longer obligitory (as it is with the US dollar) and the El Salvador government no longer accepts bitcoin for payment of taxes or fees.
Sources: en.wikipedia.org
== Clinical translation == Dextran has yet to be approved for any clinical uses in drug delivery due to a wide variety of limitations including heterogeneity, undesirable side effects, and unknown biological pathways. Changes in the molecular weight of dextran have been shown to alter biological activity, indicating a need for separation and purification processes to ensure batch homogeneity. Dextran, although considered relatively safe and nontoxic in vivo, exhibits a few side effects with the most notable being thrombocytopenia and liver toxicity. The exact biological mechanisms by which dextran-based drug delivery systems act on the drug target must be elucidated as well. Dextran-based drug delivery systems have an enormous potential for clinical use in the treatment of a variety of disease states.
==== Privatization of waterways in the North, Recife Metro and COMPESA ==== In June 2025, the Lula government, despite strong popular opposition, supported the privatization of the Recife Metro and of the COMPESA (the Pernambuco sanitation company responsible for water supply in the state), measures announced by the governor of Pernambuco, Raquel Lyra. In both cases, the BNDES, under the leadership of Aloizio Mercadante, organized the studies to make the privatization process feasible and will also conduct the bidding procedures. In late May, the chief of staff, Rui Costa, had already confirmed that the Recife Metro would be privatized, continuing a process initiated in 2019 during the Jair Bolsonaro administration. The argument used by the government to justify the measure is that the metro system generates only financial losses. The decision prompted protests in Pernambuco, especially in Recife. In addition, in September 2025 the government included the waterway of the Madeira River and the waterways of the Tocantins and Tapajós rivers in the National Privatization Program (PND), a measure that also received criticism. During the 2022 presidential campaign and in government, Lula strongly criticized the privatizations carried out by the previous administration and even promised that the Recife Metro would not be privatized. The privatization measures were criticized especially by the more radical sectors of the Brazilian left, which also criticized the government's attempt to soften the term “privatization” by presenting them as “concessions”.
==== Phase I and II trials ==== Clinical trials are ongoing for several diseases and conditions including: Acromegaly, age related macular degeneration, Alzheimer's disease, amyotrophic lateral sclerosis, autosomal dominant retinitis pigmentosa, beta thalassemia, cardiovascular disease, elevated level of lipoprotein(a), centronuclear myopathy, coagulopathies, Creutzfeldt–Jakob disease, cystic fibrosis, dentatorubral–pallidoluysian atrophy, Duchenne muscular dystrophy, diabetes, epidermolysis bullosa dystrophica, familial chylomicronemia syndrome, frontotemporal dementia, Fuchs' dystrophy, hepatitis B, hereditary angioedema, hypertension, IgA nephropathy, Kjer's optic neuropathy, Leber's hereditary optic neuropathy, multiple system atrophy, non-alcoholic fatty liver disease, Parkinson's disease, prostate cancer, Stargardt disease, STAT3-expressing cancers, Usher syndrome.
== History == Both Adolf Jarisch, an Austrian dermatologist, and Karl Herxheimer, a German dermatologist, are credited with the discovery of the Jarisch–Herxheimer reaction. Both Jarisch and Herxheimer observed reactions in patients with syphilis treated with mercury. The reaction was first seen following treatment in early and later stages of syphilis treated with Salvarsan, mercury, or antibiotics. Jarisch thought that the reaction was caused by a toxin released from the dying spirochetes.
Sources: en.wikipedia.org
==== OXA-48-like carbapenemases ==== The spread of OXA-48 carbapenem resistance involves both the expansion of successful bacterial clones and the movement of blaOXA-48 between bacteria on mobile genetic elements. The gene is commonly associated with Tn1999-family transposons carried on highly conjugative IncL plasmids, although OXA-48-like genes also occur in other plasmid types and chromosomal contexts. A community outbreak in New Zealand during 2018–2022 involved 25 patients with OXA-48-producing Escherichia coli sequence type 131. Eighteen patients had visited the same community food premises, where four food handlers were also found to be colonized, and whole-genome sequencing demonstrated genomic links between patient and food-handler isolates. Subsequent long-read genomic analysis found that the outbreak lineage had acquired blaOXA-48 on a 7,872-base-pair Col156 plasmid and identified a single IS1-mediated transposition of the resistance gene into the Col156 plasmid backbone. Analysis of global genomic data showed that blaOXA-48 occurs in diverse plasmid and insertion-sequence contexts among Enterobacterales.
== North German Confederation (1867–1871) == The North German Confederation came into existence after the German Confederation was dissolved following the Prussian victory in the Austro-Prussian War of 1866. The chancellor was appointed by the Bundespräsidium, a position that was held constitutionally by the Prussian king. Political parties: None
Subcutaneous adipose tissue is also a source of mesenchymal stem cells and have demonstrated positive outcomes in terms of cardiovascular tissue remodeling. Mammal hearts also host naturally occurring cardiac stem cells which may be capable of differentiating themselves into cardiomyocytes, endothelial cells and cardiac fibroblasts. This self-regeneration capacity gives rise to alternatives to classical cellular therapies whereby administration of growth factors such as Thymosin β4 for cell activation and migration are solely necessary. Largely democratized in terms of population information, embryonic stem cells are known for their strong capacity for expansion and differentiation into cardiomyocytes, endothelial cells and cardiac fibroblasts. However, if non autologous, immunosuppression therapy is associated with such treatment. Hence, research has been focused on induced pluripotent stem cells (iPSCs) from somatic human tissue. Further to cell and necessary relevant growth factor selection, cell delivery is an important issue. Indeed, the intracoronary route is the most straightforward cell delivery route as associated with intramyocardial cellular retention; retention rates are however low, i.e. exceed 10%. Washed off cells reach other organs or die, which can be an issue at the time of prepare ICH module 8. Other alternative injection routes have been studied, namely injection via sternotomy, endomyocardial and intracoronary routes.
Camptotheca (Camptothecin · Topotecan · Irinotecan · Rubitecan · Belotecan); 2. Podophyllum (Etoposide · Teniposide); 3a. Anthracyclines (Aclarubicin · Daunorubicin · Doxorubicin · Epirubicin · Idarubicin · Amrubicin · Pirarubicin · Valrubicin · Zorubicin); 3b. Anthracenediones (Mitoxantrone · Pixantrone). The second main approach involves ethnobotany, the study of the general use of plants in society, and ethnopharmacology, an area inside ethnobotany, which is focused specifically on medicinal uses. Artemisinin, an antimalarial agent from sweet wormtree Artemisia annua, used in Chinese medicine since 200BC is one drug used as part of combination therapy for multiresistant Plasmodium falciparum.
==== Aldol addition ==== A one- or two-fold aldol condensation of N-acetylated 2,5-DKP 8 gives access to 3-dehydro-2,5-diketopiperazines 9 and 3,6-didehydro-2,5-diketopiperazines 10 and the condensation of 8 can controlled in a stepwise fashion using triethylamine in dimethylformamide to give the unsymmetrical 3,6-didehydro-2,5-diketopiperazines 10 (R1 = Ar1, R2 = Ar2).
Sources: en.wikipedia.org
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
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.