GRF(1-29) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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 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 |
|---|---|---|
| Primary target | GHRH receptor | G-protein-coupled receptor on pituitary somatotrophs |
| Half-life, long-acting form | Several days | Extended by covalent albumin binding |
| Half-life, short form | About 30 minutes | Cleared rapidly by peptidases and kidneys |
| Route in studies | Subcutaneous injection | Used in the published human trials |
| Main measured effect | Rise in GH and IGF-1 | Surrogate markers rather than clinical endpoints |
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.
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.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
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.
Five years later, GSK shuttered the Sirtris program without successful drug development. In 2006, Sinclair co-founded Genocea Biosciences, a company founded based on the work of Harvard scientist Darren E. Higgins around antigens that stimulate T cells and the use of these antigens to create vaccines; The company delisted from the NASDAQ and closed in 2022 due to lack of funding. In 2008, Sinclair was promoted to tenured professor at Harvard Medical School. A few years later, he also became a conjoint professor at the School of Medical Sciences at the University of New South Wales. In 2008, he also joined the scientific advisory board of Shaklee and helped them devise and introduce a product containing resveratrol called "Vivix". He later disputed the use of his name and words to promote the supplement, and resigned from the board. In 2011, Sinclair co-founded OvaScience along with Michelle Dipp, Aldrich, Westphal, and Jonathan Tilly. The company was based on scientific work done by Tilly concerning mammalian oogonial stem cells and work on mitochondria by Sinclair. The company merged with Millendo Therapeutics in 2018. In 2011, he also co-founded CohBar along with Nir Barzilai and other colleagues. CohBar aimed to discover and develop novel peptides derived from mitochondria. CohBar delisted from the NASDAQ upon belief that it was a public shell. In 2015, he co-founded Metro Biotech along with Washington University in St. Louis professor Dr. Rajendra Apte. The pharmaceutical company focused on NAD+ precursors such as NMN.
In general, DPP-4 inhibitors are not very stable compounds. Therefore, many researchers focus on enhancing the stability for cyanopyrrolidines. The most widespread technique to improve chemical stability is to incorporate a steric bulk. The two cyanopyrrolidines that have been most pronounced, vildagliptin and saxagliptin, were created in this manner. K579 is a DPP-4 inhibitor discovered by researchers at Kyowa Hakko Kyogo. It had improved not only chemical stability but also a longer-lasting action. That long-lasting action was most likely due to slow dissociation of the enzyme-inhibitor complex and an active oxide metabolite that undergoes enterohepatic circulation. The discovery of the active oxide was in fact a big breakthrough as it led to the development of vildagliptin and saxagliptin. One major problem in DPP-4 inhibitor stability is intramolecular cyclization. The precondition for the intramolecular cyclization is the conversion of the trans-rotamer, which is the DPP-4 binding rotamer (Figure 5). Thus, preventing this conversion will increase stability. This prevention was successful when incorporating an amide group into a ring, creating a compound that kept the DPP-4 inhibitory activity that, did not undergo the intramolecular cyclization and was even more selective over different DPP enzymes. It has also been reported that a cyanoazetidine in the P1 position and a β-amino acid in the P2 position increased stability.
His speech from the embassy's balcony, which included the line, "Wir sind zu Ihnen gekommen, um Ihnen mitzuteilen, dass heute Ihre Ausreise..." ("We came to you, to let you know that today, your departure...") was met with loud cheers and jubilations. The next day, the first of the embassy refugees left Prague for Bavaria. The emigration was initially tolerated because of long-standing agreements with the communist Czechoslovak government, allowing free travel across their common border. However, this movement of people grew so large it caused difficulties for both countries. In addition, East Germany was struggling to meet loan payments on foreign borrowings; Egon Krenz sent Alexander Schalck-Golodkowski to unsuccessfully ask West Germany for a short-term loan to make interest payments.
August 19 – Jessica Bowie, a 35-year-old woman, is arrested over an alleged Islamic State-inspired terrorist attack on the New York State capital. August 20 Declaring "economic D-day," Trump announces that any nation trading with Iran will be sanctioned. Reuters reports that more than 150 Polymarket wallets may have traded using non-public U.S. military information. The Asia-based USS George Washington replaces Abraham Lincoln. August 22 The Trump administration informs Congress that it intends to pay $850 million of the several billion dollars it owes the UN, the highest payment the administration has made to the international body since demanding major reforms in exchange for ongoing support as its largest donor. 50% tariffs are imposed by the Trump administration on Canadian exports. A court in New York overturns the Trump policy of suspending the processing of immigration visas from 75 nations. Far-right activist Jake Lang, who was pardoned last year for his role in the January 6 riot at the United States Capitol, is arrested during a protest in Minneapolis, Minnesota. August 23 – The Freedom 250 Grand Prix is held at the National Mall as part of the United States Semiquincentennial celebrations. August 24 US Treasury Secretary Scott Bessent announces a new U.S. sanctions campaign against the Iranian government dubbed Operation Economic Outcast, warning that every country has a set deadline to halt economic activities with the government identified by Washington or risk Treasury action that includes the removal of the US dollar financial system.
Sources: en.wikipedia.org
==== Combination with other medications ==== When used for type 2 diabetes, metformin is often prescribed in combination with other medications. Several medications are available as fixed-dose combinations, with the potential to reduce pill burden, decrease cost, and simplify administration.
As nicotine enters the body, it is distributed quickly through the bloodstream and crosses the blood–brain barrier reaching the brain within 10–20 seconds after inhalation. The elimination half-life of nicotine in the body is around two hours. Nicotine is primarily excreted in urine and urinary concentrations vary depending upon urine flow rate and urine pH. The amount of nicotine absorbed by the body from smoking can depend on many factors, including the types of tobacco, whether the smoke is inhaled, and whether a filter is used. However, it has been found that the nicotine yield of individual products has only a small effect (4.4%) on the blood concentration of nicotine, suggesting "the assumed health advantage of switching to lower-tar and lower-nicotine cigarettes may be largely offset by the tendency of smokers to compensate by increasing inhalation". Cotinine is an active metabolite of nicotine that remains in the blood with a half-life of 18–20 hours, making it easier to analyze due to longer half-life than that of nicotine itself. Nicotine is metabolized in the liver by cytochrome P450 enzymes (mostly CYP2A6, and also by CYP2B6) and FMO3, which selectively metabolizes (S)-nicotine. A major metabolite is cotinine. Other primary metabolites include nicotine N-oxide, nornicotine, nicotine isomethonium ion, 2-hydroxynicotine and nicotine glucuronide. Under some conditions, other substances may be formed such as myosmine.
== External links == Academy of Managed Care Pharmacy American College of Clinical Pharmacy Board of Pharmacy Specialties Journal of Clinical Pharmacy and Therapeutics The British Journal of Clinical Pharmacy United Kingdom Clinical Pharmacy Association Clinical Pharmacy Education, Practice and Research
Prazepam is a benzodiazepine derivative drug developed by Warner-Lambert in the 1960s. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. Prazepam, (Elimination half-life 29-224h), is a prodrug for desmethyldiazepam, (Elimination half-life 36-200h), which is responsible for the therapeutic effects of prazepam.
Common gastrointestinal side effects such as nausea, diarrhea, and vomiting are also associated with donepezil and other acetylcholinesterase inhibitors. Studies have also shown an association of donepezil use and nightmares due to increased activation of the visual cortex during sleep. Patients can be advised to complete their drug regimen in the morning to prevent occurrences of nightmares.
Sources: en.wikipedia.org
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.
The drug affinity complex links the peptide to serum albumin through a covalent bond. The conjugate is too large to be filtered quickly by the kidneys and is shielded from enzymatic breakdown. This extends the apparent half-life from roughly minutes to several days.
Long-term safety and any clinical benefit are unestablished. Published human data cover small groups over limited periods and focus on hormone levels rather than health outcomes. Whether prolonged elevation of growth hormone and insulin-like growth factor 1 is beneficial or harmful is an open question.
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.