The short version of GHS-R1a fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-19 and is reviewed periodically as new material appears.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue family. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues that resist enzymatic breakdown. Researchers at Novo Nordisk described the compound in the 1990s while searching for agents that release growth hormone with fewer side effects than earlier secretagogues. The molecule acts as an agonist at the ghrelin receptor, also called GHS-R1a, which is expressed in the pituitary and in several peripheral tissues.
Selectivity distinguishes ipamorelin from first-generation secretagogues such as GHRP-6. At doses that reliably raise growth hormone, it shows little stimulation of adrenocorticotropic hormone or cortisol release in animal models, and it does not markedly raise prolactin or appetite. Binding at GHS-R1a on pituitary somatotrophs triggers calcium influx and pulsatile growth hormone secretion. Because the compound mimics the natural ghrelin signal, the release pattern tends to follow the body's own rhythm rather than producing a sustained elevation.
Most published work on ipamorelin comes from rodent studies and small early-phase human trials. Subcutaneous and intravenous routes have been used, while oral delivery is limited by poor absorption and rapid breakdown in the gut. The reported plasma half-life is short, on the order of two hours, and varies with species and assay method. Whether chronic use produces meaningful clinical benefit remains unresolved, and long-term safety data in humans are sparse. No major regulatory agency has approved the compound as a therapeutic drug.
Purity assessment for this peptide relies mainly on reversed-phase high-performance liquid chromatography. A C18 column with a water-acetonitrile gradient containing trifluoroacetic acid separates the target from truncated sequences and oxidation products. Detection near 214 nm exploits the amide backbone, while the aromatic side chains allow additional monitoring close to 280 nm. Reported purity values depend on the method, so a certificate of analysis carries weight only when gradient, column and integration parameters are given.
Mass spectrometry confirms identity and reveals structural deviations that chromatography alone can miss. Positive-mode electrospray ionisation generally yields multiply charged ions whose deconvoluted mass is checked against the theoretical value. Amino acid analysis, and enzymatic digestion with subsequent fragment mapping, provide independent confirmation of sequence and of the terminal amide. Analysts take care to separate the target from deletion sequences, which may differ by one residue and therefore by only a small mass increment.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Includes two non-natural residues |
| Molecular weight | About 711.9 g/mol | Confirmed by mass spectrometry |
| Appearance | White to off-white powder | Typical lyophilized form |
| Receptor target | GHS-R1a | Ghrelin receptor agonist |
| Plasma half-life | Roughly 2 hours | Varies by species and assay |
Ipamorelin is a synthetic pentapeptide that acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. Its sequence incorporates non-natural residues, which slows enzymatic breakdown relative to short native peptides. In laboratory and early clinical work the compound is described as a selective growth hormone secretagogue because it raises growth hormone with comparatively little effect on other pituitary outputs. The degree to which that selectivity holds across species and dosing regimens remains an open question in the published literature.
Signal transduction begins when the peptide binds GHSR-1a on pituitary somatotrophs. The receptor couples to Gq/11 proteins, activating phospholipase C, which cleaves phosphatidylinositol bisphosphate into inositol trisphosphate and diacylglycerol. Inositol trisphosphate releases calcium from intracellular stores, and the resulting rise in cytosolic calcium drives growth hormone vesicle fusion. Concurrent Gs coupling and cyclic AMP elevation have also been reported, and the relative contribution of each arm to the overall secretory response is not fully settled.
Ipamorelin is a synthetic pentapeptide first described in the 1990s by researchers at Novo Nordisk during a program to develop selective growth hormone secretagogues. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues, alpha-aminoisobutyric acid and D-2-naphthylalanine. The C-terminus is amidated, and the material is supplied as a white lyophilized powder. The molecular formula is C38H49N9O5 and the monoisotopic mass is approximately 711.85 daltons. The short chain and modified residues give it greater resistance to enzymatic degradation than many larger peptide hormones.
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor type 1a, the same G protein-coupled receptor that binds ghrelin. Receptor activation couples to Gq/11 signaling, raising intracellular calcium through inositol trisphosphate and diacylglycerol, which in turn promotes exocytosis of growth hormone from pituitary somatotroph cells. Ipamorelin binds this receptor with high affinity and shows weak activity at other secretagogue-related targets in vitro. Its action requires the intact receptor and is not reversed by growth hormone-releasing hormone antagonists.
Lyophilized ipamorelin powder is the form usually supplied for laboratory work. Kept dry, protected from light, and held at minus 20 degrees Celsius or below, it remains stable for extended periods, often measured in years. Once dissolved, the peptide degrades faster through hydrolysis, oxidation, and deamidation, so solutions are typically refrigerated and used within weeks. Repeated freeze-thaw cycles and exposure to alkaline conditions accelerate loss of the parent compound.
Reversed-phase high-performance liquid chromatography is the standard tool for assessing purity. Detection near 214 nanometers captures the peptide backbone, and the resulting chromatogram shows the main peak alongside related impurities. Electrospray ionization mass spectrometry confirms molecular mass and supports sequence verification. Common degradation products include oxidized residues, deamidated forms, and truncated fragments, each appearing as a distinct peak or shoulder in the trace.
Carbamazepine is typically used for the treatment of seizure disorders and neuropathic pain. It is used off-label as a second-line treatment for bipolar disorder and in combination with an antipsychotic in some cases of schizophrenia when treatment with a conventional antipsychotic alone has failed. However, evidence does not support its usage for schizophrenia. It is not effective for absence seizures or myoclonic seizures. Although carbamazepine may have a similar effectiveness (as measured by people continuing to use a medication) and efficacy (as measured by the medicine reducing seizure recurrence and improving remission) when compared to phenytoin and valproate, it is not well-researched which medication is most helpful for people with newly-onset seizures. In the United States, carbamazepine is indicated for the treatment of epilepsy (including partial seizures, generalized tonic-clonic seizures and mixed seizures), and trigeminal neuralgia. Carbamazepine is the only medication that is approved by the Food and Drug Administration for the treatment of trigeminal neuralgia. As of 2014, a controlled release formulation was available for which there is tentative evidence showing fewer side effects and unclear evidence with regard to whether there is a difference in efficacy. In 2016, the FDA approved an intravenous formulation of carbamazepine, also granting it orphan drug status under the trade name Carnexiv, as a short-term replacement therapy for oral carbamazepine in adults with specific types of seizure disorders, who are unable to tolerate the oral formulation.
==== United States ==== The list price of a year's treatment in the US is US$322,000 (formerly US$311,000). However, a 2020 report by Institute for Clinical and Economic Review found that the price has made the treatment not cost effective and that "an appropriate health-benefit price would range from $67,900–$85,500 per year".
== Names == In Middle English, dried and salted cod was called haberdine. Dried cod and the dishes made from it are known by many names around the world, many of them derived from the root bacal-, itself of unknown origin. Explorer John Cabot reported that it was the name used by the inhabitants of Newfoundland. Some of these are: bacalhau (salgado) (Portuguese), bacalao salado (Spanish), bacallau salgado (Galician), bakailao (Basque), bacallà salat i assecat or bacallà salat (Catalan), μπακαλιάρος, bakaliáros (Greek), Klippfisch (German), morue salée (French), baccalà (Italian), bacałà (Venetian), bakalar (Croatian), bakkeljauw (Surinamese Dutch), bakaljaw (Maltese), makayabu (Central and East Africa), Okporoko (Igbo-Nigeria) and kapakala (Finnish). Other names include ráktoguolli/goikeguolli (Sami), klipfisk (Danish) klippfisk/kabeljo (Swedish), stokvis/klipvis (Netherlandish Dutch), saltfiskur [ˈsal̥tˌfɪskʏr̥] (Icelandic), morue (French), bartolitius (Canadian), and saltfish (Anglophone I Caribbean).
Sources: en.wikipedia.org
=== Deep Learning === More recently, deep learning techniques have been applied to solve the de novo peptide sequencing problem. The first breakthrough was DeepNovo, which adopted the convolutional neural network structure, achieved major improvements in sequence accuracy, and enabled complete protein sequence assembly without assisting databases Subsequently, additional network structures, such as PointNet (PointNovo), have been adopted to extract features from a raw spectrum. The de novo peptide sequencing problem is then framed as a sequence prediction problem. Given previously predicted partial peptide sequence, neural-network-based de novo peptide sequencing models will repeatedly generate the most probable next amino acid until the predicted peptide's mass matches the precursor mass. At inference time, search strategies such as beam search can be adopted to explore a larger search space while keeping the computational cost low. Comparing with previous methods, neural-network-based models have demonstrated significantly better accuracy and sensitivity. Moreover, with a careful model design, deep-learning-based de novo peptide sequencing algorithms can also be fast enough to achieve real-time peptide de novo sequencing. PEAKS software incorporates this neural network learning in their de novo sequencing algorithms.
== Target and events == The primary target of the doctrine was originally the largest communist country, the Soviet Union. However, additional targets also included the other communist countries like the China, Laos, Vietnam, and North Korea. After the dissolution of the Soviet Union in 1991 and China's economic prominence in the early 21st century, China became the major target of the doctrine.
=== Other fronts === Mexico's participation in World War II was not exclusive to the 201st Squadron. Thousands of Mexicans fought on the battlefield as volunteers in foreign armies or as residents of other countries. There are figures of between 50 thousand to 80 thousand Mexicans who fought on different fronts, many of them did so voluntarily. On D-Day there were also Mexican fighters, all of whom were volunteers and born in other countries, including Luis Pérez Gómez (1922-1944), who enlisted as a pilot in the Royal Canadian Air Force, participating in various missions during the Normandy landings. One of the most prominent Mexicans as reinforcements for other troops was José M. López, who fought alongside the American troops and his bravery in the conflict was such that after the Allied victory, he was awarded the Medal of Honor, the highest decoration in the US Army. This after his participation in the Battle of the Bulge, where he and other soldiers counterattacked the German offensive. Mendoza, with a machine gun, left almost 100 casualties to the Germans.
Sources: en.wikipedia.org
The peptide is Aib-His-D-2-Nal-D-Phe-Lys-NH2. Two of its residues are non-natural, which slows enzymatic degradation. The C-terminal amide is common among bioactive peptides.
It binds the same ghrelin receptor but with greater selectivity in functional assays. Preclinical work reports less cortisol and prolactin stimulation at growth-hormone-releasing doses. Those differences are relative, not absolute, and depend on dose and model.
No major regulatory authority has approved it for human therapeutic use. It is sold as a research chemical for laboratory investigation. Clinical status varies by country and is subject to change.
Results are most often expressed as a percentage of total peak area from a reversed-phase separation. That figure reflects the detection wavelength, gradient and integration choices used by the laboratory. Two valid certificates can therefore quote different values for the same material without either being incorrect.