GHRH receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-25. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C152H252N44O42 | Cited for the form without the drug affinity complex |
| Molecular weight | About 3368 Da | Reported value for modified GRF(1-29) |
| Appearance | White to off-white powder | Lyophilised solid as usually supplied |
| Solubility | Soluble in water and polar solvents | Clarity depends on purity and salt content |
| Typical storage | -20 C or below, dry | Protect from light and repeated warming cycles |
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
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.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
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.
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.
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.
=== Applications for oceanography === Tracers are also used extensively in oceanography to study a wide array of processes. The isotopes used are typically naturally occurring with well-established sources and rates of formation and decay. However, anthropogenic isotopes may also be used with great success. The researchers measure the isotopic ratios at different locations and times to infer information about the physical processes of the ocean.
== Further reading == Bowen, W. Richard; Mohammad, A. Wahab (Aug 1998). "Diafiltration by nanofiltration: Prediction and optimization". AIChE Journal. 44 (8): 1799–1812. Bibcode:1998AIChE..44.1799R. doi:10.1002/aic.690440811. Limayem, Imène; Charcosset, Catherine; Fessi, Hatem (2004). "Purification of nanoparticle suspensions by a concentration/diafiltration process". Separation and Purification Technology. 38 (1): 1–9. doi:10.1016/j.seppur.2003.10.002. Sheth, Jignesh P.; et al. (2003). "Nanofiltration-based diafiltration process for solvent exchange in pharmaceutical manufacturing". Journal of Membrane Science. 211 (2): 251–261. doi:10.1016/s0376-7388(02)00423-4.
Dissatisfied with the audio quality of their initial album recording sessions, the group re-recorded and remixed the material at Toronto Sound in late 1973 with the more experienced Terry Brown, which marked the beginning of a ten-year creative partnership. To help raise the $9,000 required to complete the album, Danniels sold his interest in his management company. Although Rutsey was originally tasked with writing the lyrics, he tore up his drafts immediately prior to the vocal sessions; Lee subsequently composed a new set of lyrics based on earlier versions to complete the album's final takes. Rutsey looked back on this incident with regret, and put it down to feeling "very confused about what I really wanted to do." Following a delay attributed to a provincial vinyl shortage, the self-titled debut, Rush, was released in March 1974. An initial pressing of 3,500 copies sold out quickly, and the album eventually reached No. 86 on the RPM Top Albums chart. While contemporary critics often critisised the album as derivative of Led Zeppelin, it gained traction in the United States after Donna Halper, music director and DJ at WMMS in Cleveland, had received a copy and added "Working Man" to the station's rotation. The song's blue-collar themes resonated with the city's industrial workforce, triggering a surge in demand for the Canadian import. To capitalise on this regional interest, Danniels secured a slot for the band opening for ZZ Top at Cleveland's Allen Theatre in June 1974.
Sources: en.wikipedia.org
=== Amino acid propensities === Large aromatic residues (tyrosine, phenylalanine, tryptophan) and β-branched amino acids (threonine, valine, isoleucine) are favored to be found in β-strands in the middle of β-sheets. Different types of residues (such as proline) are likely to be found in the edge strands in β-sheets, presumably to avoid the "edge-to-edge" association between proteins that might lead to aggregation and amyloid formation.
At Nagapatnam, Pulicat, and elsewhere, the company purchased 8,000–10,000 slaves, the bulk of whom were sent to Ceylon, while a small portion were exported to Batavia and Malacca. Finally, following a long drought in Madurai and southern Coromandel, in 1673, which intensified the prolonged Madurai-Maratha struggle over Tanjavur and punitive fiscal practices, thousands of people from Tanjavur, mostly children, were sold into slavery and exported by Asian traders from Nagapattinam to Aceh, Johor, and other slave markets. In September 1687, 665 slaves were exported by the English from Fort St. George, Madras. And, in 1694–96, when warfare once more ravaged South India, a total of 3,859 slaves were imported from Coromandel by private individuals into Ceylon. The volume of the total Dutch Indian Ocean slave trade has been estimated to be about 15–30% of the Atlantic slave trade, slightly smaller than the trans-Saharan slave trade, and one-and-a-half to three times the size of the Swahili and Red Sea coast and the Dutch West India Company slave trades. According to Sir Henry Bartle Frere (who sat on the Viceroy's Council), there were an estimated 8 or 9 million slaves in India in 1841. About 15% of the population of Malabar were slaves. Slavery was legally abolished in the possessions of the East India Company by the Indian Slavery Act, 1843.
== External links == Cut-Flower Care — How to Make Your Fresh-Cut Flowers Last by Rose G. Edinger, Brooklyn Botanical Garden, Spring 2003, retrieved October 21, 2006 — What are preserved flowers? Everything you want to know about preserved flowers Archived 2021-01-28 at the Wayback Machine by Floralonly, Albert, published 28, May 2020
In 2009, Lilly pleaded guilty for illegally marketing antipsychotic medication Zyprexa and agreed to pay a $1.415 billion penalty that included a criminal fine of $515 million, the largest ever in a healthcare case and the largest criminal fine for an individual corporation ever imposed in a US criminal prosecution of any kind at the time. Eli Lilly has faced many lawsuits from people who claimed they developed diabetes or other diseases after taking olanzapine (branded Zyprexa), an antipsychotic medication, as well as by various governmental entities, insurance companies, and others. Internal documents provided to The New York Times revealed that Lilly had downplayed the risks of Zyprexa. According to the documents, 16 percent of people taking Zyprexa gained more than 66 pounds in their first year, a much larger figure than Eli Lilly had shared with doctors. In 2006, Lilly paid $700 million to settle around 8,000 of these lawsuits, and in early 2007, Lilly settled around 18,000 suits for $500 million, which brought the total Lilly had paid to settle suits related to the drug to $1.2 billion. In March 2008, Lilly settled a suit with the state of Alaska, and in October 2008, Lilly agreed to pay $62 million to 32 states and the District of Columbia to settle suits brought under state consumer protection laws. In 2009, four sales representatives for Eli Lilly filed separate qui tam lawsuits against the company for illegally marketing Zyprexa for uses not approved by the Food and Drug Administration.
Sources: en.wikipedia.org
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.
No regulatory agency has approved CJC-1295 for clinical use. Human trials were conducted in the 2000s, but the development programme was discontinued before any marketing application succeeded. Material sold today is offered as a research chemical, and its purity depends on the supplier.
Sermorelin is an unmodified fragment of growth hormone-releasing hormone and is cleared quickly. CJC-1295 contains substitutions that resist breakdown, and the form with a drug affinity complex persists much longer. Both act at the same receptor but differ substantially in duration of action.
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.