If you have been reading about IGF-1 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 2026-02-25. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
| Property | Value | Notes |
|---|---|---|
| Molecular weight, DAC form | About 3647 Da | Varies with salt form |
| Molecular weight, non-DAC form | About 3358 Da | MOD GRF(1-29) |
| Solubility class | Water soluble | Also dissolves in polar solvents |
| Reported half-life, DAC form | About five to eight days | Values from human studies |
| Common synonyms | CJC-1295; MOD GRF(1-29) | Name depends on variant |
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.
Reported half-lives differ widely between the two variants and between species. Values for the albumin-binding form are usually expressed in days, while the unconjugated form is measured in minutes to a few hours. Sampling schedules, assay sensitivity, and route of administration all influence the numbers, which limits direct comparison across studies. Whether sustained receptor occupancy produces different downstream effects from pulsatile stimulation remains an open question in the published work. Claims about relative potency should therefore be read alongside the specific study design that produced them.
Reports on this compound commonly follow serum growth hormone and insulin-like growth factor 1 across defined time windows. Protocols differ in sampling frequency, assay platform, and participant characteristics, which makes direct comparison between publications difficult. Some work focuses on pulsatile release patterns instead of average concentrations. Whether repeated exposure alters endogenous hormone rhythms over long periods remains an open question, and the formal literature is thinner than the volume of informal commentary implies.
Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
=== set-sez === setastine (INN) setazindol (INN) Sethotope setileuton (USAN, INN) setipafant (INN) setipiprant (INN) setiptiline (INN) setoperone (INN) setrobuvir (USAN) sevabertinib (USAN, INN) sevelamer (INN) sevirumab (INN) sevitropium mesilate (INN) sevoflurane (INN) sevopramide (INN) Sevorane Sevorane AF sezolamide (INN)
== Support-free liquid chromatography == Standard column chromatography consists of a solid stationary phase and a liquid mobile phase, while gas chromatography (GC) uses a solid or liquid stationary phase on a solid support and a gaseous mobile phase. By contrast, in liquid-liquid chromatography, both the mobile and stationary phases are liquid. The contrast is, however, not as stark as it first appears. In reversed-phase chromatography, for example, the stationary phase can be regarded as a liquid which is immobilized by chemical bonding to a micro-porous silica solid support. In countercurrent chromatography centripetal or gravitational forces immobilize the stationary liquid layer. By eliminating solid supports, permanent adsorption of the analyte onto the column is avoided, and a high recovery of the analyte can be achieved. The countercurrent chromatography instrument is easily switched between normal phase chromatography and reversed-phase chromatography simply by changing the mobile and stationary phases. With column chromatography, the separation potential is limited by the commercially available stationary phase media and its particular characteristics. Nearly any pair of immiscible solutions can be used in countercurrent chromatography provided that the stationary phase can be successfully retained. Solvent costs are also generally lower than for HPLC. In comparison to column chromatography, flows and total solvent usage can in most countercurrent chromatography separations may be reduced by half and even up to a tenth.
== Toxicity == A study was performed to assess the toxicity effects of doxorubicin-loaded polymeric nanoparticle systems. It was found that doses up to 400 mg/kg of PBCA nanoparticles alone did not cause any toxic effects on the organism. These low toxicity effects can most likely be attributed to the controlled release and modified biodistribution of the drug due to the traits of the nanoparticle delivery system. Toxicity is a highly important factor and limit of drug delivery studies, and a major area of interest in research on nanoparticle delivery to the brain.
Sources: en.wikipedia.org
=== Tertiary dentin (including reparative dentin and reactionary dentin) – pathologic === Tertiary dentin is dentin formed as a reaction to external stimulation such as cavities and wear. It is of two types, either reactionary, where dentin is formed from a pre-existing odontoblast, or reparative, where newly differentiated odontoblast-like cells are formed due to the death of the original odontoblasts, from a pulpal progenitor cell. Tertiary dentin is only formed by an odontoblast directly affected by a stimulus; therefore, the architecture and structure depend on the intensity and duration of the stimulus, e.g., if the stimulus is a carious lesion, there is extensive destruction of dentin and damage to the pulp, due to the differentiation of bacterial metabolites and toxins. Thus, tertiary dentin is deposited rapidly, with a sparse and irregular tubular pattern and some cellular inclusions; in this case, it is referred to as "osteodentin". Osteodentin is seen in Vit.A deficiency during development. However, if the stimulus is less active, it is laid down less rapidly with a more regular tubular pattern and hardly any cellular inclusions. The speed at which tertiary dentin forms also varies substantially among primate species.
=== Support groups === The Juvenile Scleroderma Network is an organization dedicated to providing emotional support and educational information to parents and their children living with juvenile scleroderma, supporting pediatric research to identify the cause of and the cure for juvenile scleroderma, and enhancing public awareness. In the US, the Scleroderma Foundation is dedicated to raise awareness of the disease and assist those who are affected. The Scleroderma Research Foundation sponsors research into the condition. Comedian and television presenter Bob Saget, a board member of the SRF, directed the 1996 ABC TV movie For Hope, starring Dana Delany, which depicts a young woman fatally affected by scleroderma; the film was based on the experiences of Saget's sister Gay. Scleroderma and Raynaud's UK is a British charity formed by the merger of two smaller organisations in 2016 to provide support for people with scleroderma and fund research into the condition.
Although the term was coined in the late 1980s one of the first retroactively recognized examples of a killer application is the VisiCalc spreadsheet, released in 1979 for the Apple II. Because it was not released for other computers for 12 months, people spent US$100 (equivalent to $400 in 2025) for the software first, then $2,000 to $10,000 (equivalent to $9,000 to $44,000) on the requisite Apple II. Byte wrote in 1980, "VisiCalc is the first program available on a microcomputer that has been responsible for sales of entire systems", and Creative Computing's VisiCalc review is subtitled "reason enough for owning a computer". Others also chose to develop software, such as EasyWriter, for the Apple II first because of its higher sales, helping Apple defeat rivals Commodore International and Tandy Corporation. The co-creator of WordStar, Seymour Rubinstein, argued that the honor of the first killer app should go to that popular word processor, given that it came out a year before VisiCalc and that it gave a reason for people to buy a computer. However, whereas WordStar could be considered an incremental improvement (albeit a large one) over smart typewriters like the IBM Electronic Selectric Composer, VisiCalc, with its ability to instantly recalculate rows and columns, introduced an entirely new paradigm and capability unavailable on larger computers. Lotus 1-2-3 similarly benefited sales of the IBM PC. Noting that computer purchasers did not want PC compatibility as much as compatibility with certain PC software, InfoWorld suggested "let's tell it like it is.
Sources: en.wikipedia.org
This theoretical analysis of the various isomers and experimental analysis of this reaction cast doubt on whether the mass spectrometric approach really did produce the hexathione isomer as originally claimed. The increased stability of dithietes as compared to dioxetane-like rings is one of theoretical bases for proposing C6S6 is more stable than the oxygen analog.
Pectate lyase (EC 4.2.2.2) is an enzyme involved in the maceration and soft rotting of plant tissue. Pectate lyase is responsible for the eliminative cleavage of pectate, yielding oligosaccharides with 4-deoxy-α-D-mann-4-enuronosyl groups at their non-reducing ends. The protein is maximally expressed late in pollen development. It has been suggested that the pollen expression of pectate lyase genes might relate to a requirement for pectin degradation during pollen tube growth. This enzyme catalyzes the chemical reaction
==== Israel ==== Dunkin' Donuts Israel (Hebrew: דאנקן דונאטס) was an Israeli franchise of the chain. Dunkin' Donuts Israel opened their first location in Israel in 1996 in Tel Aviv. Their main flagship store was located in Rabin Square, with their factory in Lod. Upon opening their first location, Dunkin' was a huge hit. When the original location opened, it broke Dunkin's own sales records by selling 3 million doughnuts in the first eight months. The chain's manager was quoted saying "Israelis do not stop eating doughnuts, They buy such quantities, quantities that we would never have believed they would buy. They buy boxes of 12, eat them here, and then buy more boxes to take home." In 2001, when Dunkin' Donuts Israel decided to close, the company had accumulated a large amount of debt. When the Second Intifada broke out, Israeli tourism slowed, and Dunkin' decided to close. Approximately $2 million was invested in Dunkin' Donuts Israel when it failed. At the peak, Dunkin' Donuts had 9 branches in Israel, short of their original goal of 15, including 3 in Jerusalem.
The legacy of the USSR remains a controversial topic. The socio-economic nature of communist states such as the USSR, especially under Stalin, has also been much debated, varyingly being labelled a form of bureaucratic collectivism, state capitalism, state socialism, or a totally unique mode of production. The USSR implemented a broad range of policies over a long period of time, with a large amount of conflicting policies being implemented by different leaders. Some have a positive view of it whilst others are critical towards the country, calling it a repressive oligarchy. The opinions on the USSR are complex and have changed over time, with different generations having different views on the matter as well as on Soviet policies corresponding to separate time periods during its history.
Sources: en.wikipedia.org
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.
The DAC form carries a maleimide group that binds albumin and extends circulation time. The non-DAC form lacks this group and clears much faster. Both share the same receptor-binding core.
It targets the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Activation raises cyclic AMP and promotes growth hormone release. Normal feedback pathways remain part of the response.
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.