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.
Last reviewed on 2026-03-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.
Studies in this area generally track growth hormone pulses, insulin-like growth factor 1 concentrations, and occasionally body composition endpoints. Most published human data come from early, small trials, and questions about long-term effects remain open. Whether repeated exposure alters pituitary responsiveness over time is not settled. Analytical work relies on immunoassays for the hormones and on mass spectrometry for the peptide itself, because the two measurements answer different questions.
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.
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.
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.
=== Premixed === Appropriate patient selection is an essential component of successful premixed insulin therapy. Kalra was the lead author of a comprehensive review developed with collaborators from more than 25 countries. He has also published extensively on the use of premixed insulin during Ramadan and on its role in special situations, from initiation to intensification. He has also published updates on premixed insulins, including real-world evidence regarding newer co-formulations.
=== Thermodynamic analysis === As SPR biosensors facilitate measurements at different temperatures, thermodynamic analysis can be performed to obtain a better understanding of the studied interaction. By performing measurements at different temperatures, typically between 4 and 40 °C, it is possible to relate association and dissociation rate constants with activation energy and thereby obtain thermodynamic parameters including binding enthalpy, binding entropy, Gibbs free energy and heat capacity.
Returning to Los Angeles, Parsons sought out Chris Hillman, and the two formed The Flying Burrito Brothers with bassist Chris Ethridge and pedal steel player Sneaky Pete Kleinow. Their 1969 album The Gilded Palace of Sin marked the culmination of Parsons' post-1966 musical vision: a modernized variant of the Bakersfield sound that was popularized by Buck Owens amalgamated with strands of soul and psychedelic rock. The band appeared on the album cover wearing Nudie suits emblazoned with hippie symbols, including marijuana, Tuinal, and Seconal-inspired patches. Along with the Parsons-Hillman originals "Christine's Tune" and "Sin City" were versions of the soul music classics "The Dark End of the Street" and "Do Right Woman, Do Right Man", the latter featuring David Crosby on high harmony. The original songs were the result of a productive songwriting partnership between Parsons and Hillman, who were sharing a bachelor pad in the San Fernando Valley. The pronounced gospel-soul influence on this album likely evolved from the ecumenical tastes of bassist Chris Ethridge, who co-wrote "Hot Burrito No. 1/I'm Your Toy" and "Hot Burrito No. 2" with Parsons. Original drummer Eddie Hoh was unable to perform adequate takes due to a substance abuse problem. He was dismissed after two songs and the band used session drummers, including former International Submarine Band drummer Jon Corneal and Popeye Phillips. Before commencing live performances, the group settled on original Byrds drummer Michael Clarke. The Gilded Palace of Sin was commercially unsuccessful.
=== Boiled === Eto is a Ghanaian traditional dish made from boiled and mashed yam or plantain and typically savored with boiled eggs, groundnut (peanuts) and sliced avocado. For the plantain option called 'Boodie eto', the plantain can be used unripe, slightly ripe or fully ripe. Culturally, eto was fed to a bride on the day of her marriage, but is now a popular dish enjoyed outside of special occasions as well. A traditional mangú from the Dominican Republic consists of peeled and boiled green plantains, mashed with hot water to reach a consistency slightly stiffer than mashed potatoes. It is traditionally eaten at breakfast, topped with sautéed red onions in apple cider vinegar and accompanied by fried eggs, fried cheese or fried bologna sausage, known as Dominican salami. Plantain porridge is also a common dish throughout the Caribbean, in which cooking bananas are boiled with milk, cinnamon, and nutmeg to form a thick porridge typically served at breakfast.
Check valves are often used with some types of pumps. Piston-driven and diaphragm pumps such as metering pumps and pumps for chromatography commonly use inlet and outlet ball check valves. These valves often look like small cylinders attached to the pump head on the inlet and outlet lines. Many similar pump-like mechanisms for moving volumes of fluids around use check valves such as ball check valves. The feed pumps or injectors which supply water to steam boilers are fitted with check valves to prevent back-flow. Check valves are also used in the pumps that supply water to water slides. The water to the slide flows through a pipe which doubles as the tower holding the steps to the slide. When the facility with the slide closes for the night, the check valve stops the flow of water through the pipe; when the facility reopens for the next day, the valve is opened and the flow restarts, making the slide ready for use again.
Sources: en.wikipedia.org
After an initial or primary fermentation, beer is conditioned, matured or aged, in one of several ways, which can take from 2 to 4 weeks, several months, or several years, depending on the brewer's intention for the beer. The beer is usually transferred into a second container, so that it is no longer exposed to the dead yeast and other debris (also known as "trub") that have settled to the bottom of the primary fermenter. This prevents the formation of unwanted flavours and harmful compounds such as acetaldehyde.
In June 2023, Starbucks attracted controversy for allegedly not allowing workers at some locations in 22 states to put up Pride Month decorations. It came during an ongoing public furor over the direction of LGBTQ+ rights in the US, with other major corporations, like Target and AB-InBev, which manufactures Bud Light, also receiving heightened criticism and scrutiny. A strike at some stores was announced as a result.
Failure of homeostatic mechanisms can contribute to disease; examples include type 1 diabetes, disorders of calcium regulation, and disturbances of water balance. The effectiveness of homeostatic control can also decline with aging, and compensatory mechanisms may temporarily mask chronic disease. Although primarily a biological concept, homeostasis has also been applied to the biosphere and, by analogy, in a range of other fields.
=== Oleato coffee === In February 2023, Starbucks announced it would introduce a line of coffee drinks made with extra virgin olive oil, including lattes, shaken espresso, and cold brews. This would not be a limited-time offering, but rather "'one of the biggest launches we’ve had in decades,'" according to Brady Brewer, the company's chief marketing officer. The goal was to create a new category of beverage. Unlike other drinks, this came about because of the habits of then-CEO Howard Schultz, who was introduced to consuming a teaspoon of olive oil each day by an olive oil producer he met in Sicily. The drinks were initially available in Italy and later expanded to stores in Southern California in spring 2023 and then the UK, Middle East, and Japan later the same year. After its launch, CNN reported some customers reported digestive distress after drinking the beverages. In January 2024, the company said it would introduce the beverages nationwide in the US as well as in Canada, France, and China. The Oleato beverages were permanently discontinued in November 2024.
Sources: en.wikipedia.org
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
It binds the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Receptor activation raises cyclic AMP and promotes release of stored growth hormone granules. Because the peptide persists longer than natural releasing hormone, stimulation is prolonged rather than brief.