Everything below concerns pentapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
Structural features distinguish the molecule from earlier secretagogues. An alpha-aminoisobutyric acid residue near the N-terminus and a D-naphthylalanine substitution increase receptor affinity, while C-terminal amidation improves resistance to exopeptidases. These modifications are associated with reduced stimulation of appetite and of the hypothalamic-pituitary-adrenal axis compared with hexarelin or growth hormone releasing peptide-6. Whether the same profile applies at every dose level studied is a matter of ongoing investigation rather than settled consensus.
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.
Compared with earlier growth hormone secretagogues such as GHRP-6 and hexarelin, ipamorelin has been reported to produce less stimulation of adrenocorticotropic hormone, cortisol, and prolactin in animal and early human studies. This selectivity is usually attributed to differences in receptor subtype interactions and to the tissue distribution of the receptor. Effects on appetite appear weaker than those of ghrelin itself, although the supporting evidence base is small. Whether these differences produce a distinct clinical profile remains an open question, since controlled human trials are limited.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Reported for the free peptide |
| Molecular mass | 711.85 Da | Monoisotopic value |
| Residue motif | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Non-natural residues at positions one and three |
| Primary target | GHSR-1a | Ghrelin receptor, G protein coupled |
| Reported plasma half-life | About two hours | Values vary with assay and subject group |
Quality claims for research peptides vary widely across suppliers. A certificate of analysis should list purity by chromatography, the mass found by spectrometry, and the analytical conditions used. Independent testing at a third-party laboratory is a common way to check identity and purity, because documents alone cannot confirm what is inside a vial. Purity figures describe the proportion of the target peptide among detected species, and they say nothing about biological activity or sterility.
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.
One distinguishing feature reported in animal studies is selectivity. Ipamorelin stimulated growth hormone release with limited elevation of adrenocorticotropic hormone or cortisol compared with earlier secretagogues such as GHRP-6. This pattern has been described as more selective for the growth hormone axis. The finding comes mainly from preclinical work, and the degree to which it holds across species and doses is not fully settled. Reports also describe effects on gastric motility in animal models, suggesting activity outside the pituitary, though the clinical relevance of this observation is uncertain.
Ipamorelin is a synthetic pentapeptide that acts on the growth hormone secretagogue receptor, also known as the ghrelin receptor. Its sequence contains five amino acid residues, including a non-natural residue that increases stability against enzymatic breakdown. The compound was developed in the 1990s as part of research into small peptides that stimulate pituitary hormone release. Unlike larger protein hormones, it can be produced by solid-phase peptide synthesis and characterized by standard analytical methods.
At the receptor level, ipamorelin binds GHS-R1a and triggers signaling through Gq-coupled pathways. Activation leads to calcium release and downstream effects in pituitary somatotroph cells. These events promote the release of growth hormone into circulation. The response depends on the presence of the receptor and on the physiological state of the animal or tissue studied. Because the receptor is also found in other tissues, effects beyond the pituitary have been examined in laboratory models, though the extent of those effects remains an area of ongoing study.
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
Identity and purity assessment for a research peptide of this kind typically combines reversed-phase high-performance liquid chromatography with mass spectrometry. The chromatographic run separates related impurities and yields a purity percentage, while electrospray ionization or matrix-assisted laser desorption mass spectrometry confirms the expected molecular mass. Amino acid analysis or tandem mass spectrometry sequencing can add confidence when material is intended for quantitative work. Laboratories differ in how they calculate and report purity, so figures from different sources are not always directly comparable.
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
Quality control for research-grade ipamorelin is not governed by a single harmonized pharmacopeial monograph, so certificates of analysis vary between suppliers. Common tests include appearance, solubility, water content, peptide content by quantitative amino acid analysis, and residual counterion measurement. Independent verification by an outside laboratory is often used to confirm identity and purity claims. Salt form, counterion content, and residual solvent levels are frequently unspecified, which complicates direct comparison between lots and leaves reproducibility partly unresolved.
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
== Etymology == The word pepper derives from Old English pipor, Latin piper, and Greek πέπερι. The Greek likely derives from Sanskrit. In the 16th century, people began using pepper to also mean the New World chilli pepper (genus Capsicum), which is not closely related.
== Research and career == In 2000 Pohl joined the faculty at Iowa State University. She spent twelve years in Iowa, eventually being made Wilkinson Professor of Chemistry and Biomedical Engineering. In 2008 she founded LuCELLa Biosciences, a spin-out company who specialise in the custom synthesis of carbohydrates. Pohl joined Indiana University Bloomington in 2012, where she was made the Professor and Joan & Marvin Carmack Chair. Pohl is interested in the synthesis and characterisation of sugars in an effort to better understand their role in biological function. By better understanding the interactions of carbohydrates, Pohl believes that she will be able to rationally design vaccinations and other therapies. She demonstrated an oligosaccharide synthesis process that involved automated solution-phase methods. The automation process involves the use of fluorocarbon tags that can be used to pattern the surfaces of tagged molecules to form carbohydrate microarrays. Pohl spent 2019 as a Fulbright Program scholar at the University of Natural Resources and Life Sciences, Vienna.
=== Venetia Berens === Venetia Berens (Indy Lewis) is a new grad who joins Pierpoint's FX desk in the second series. She is first seen in series 1 at a Pierpoint recruiting event, pressing Robert and Yasmin on the firm's toxic culture. Ambitious and idealistic, Venetia is determined to prove herself within Pierpoint's cutthroat work environment, provoking resentment from Yasmin over not having to face the same mistreatment she suffered in her first year. In series 2, While scouting new recruits, Venetia grows closer to Robert, to whom she is attracted, but Robert humiliates her when he makes an aggressive pitch to a student while on cocaine, wherein he suggests that Venetia is merely using achievement to seek external validation. Venetia later barges into a client dinner between Robert and Nicole Craig, unaware that they are in a sexual relationship; after Robert leaves the two alone, Nicole sexually assaults Venetia. Venetia confides this to Yasmin, but she dismisses her concerns. Venetia then goes to Kenny, who attempts to report the assault up the chain of command, but to no avail. In series 3, Venetia and Robert have begun dating. Venetia, growing increasingly tired of Pierpoint's abusive work environment, eventually quits the firm. While leaving, she reveals to Rishi that she was the one who anonymously posted to a Reddit page called "Overheard At Pierpoint", which contained many of Rishi's lewd and inappropriate comments on the trading floor.
Guinness ( ) is a stout that originated in the brewery of Arthur Guinness at St. James's Gate, Dublin, Ireland, in the 18th century. It is now owned by the British multinational alcoholic beverage maker Diageo. It is one of the most successful alcohol brands worldwide, brewed in almost 50 countries, and available in over 120. Sales in 2011 amounted to 850,000,000 litres (190,000,000 imp gal; 220,000,000 U.S. gal). It is the highest-selling beer in both Ireland and the United Kingdom. The Guinness Storehouse is a tourist attraction at St. James's Gate Brewery in Dublin, Ireland. Since opening in 2000, it has received over 20 million visitors. Adopted in 1862 by the incumbent proprietor, Benjamin Lee Guinness, the Guinness harp motif is modelled on the Trinity College harp (which is the national symbol of Ireland), with the right-facing harp registered as a trademark for Guinness in 1876. Guinness's flavour derives from malted barley and roasted unmalted barley. The unmalted barley is a relatively modern addition that became part of the grist in the mid-20th century. For many years, a portion of aged brew was blended with freshly brewed beer to give a sharp lactic acid flavour. Although Guinness's palate still features a characteristic "tang", the company has refused to confirm whether this type of blending still occurs. The draught beer's thick and creamy head comes from mixing the beer with nitrogen and carbon dioxide. Guinness moved its headquarters to London at the beginning of the Anglo-Irish trade war in 1932.
Certain elements of the Combine's appearance, such as that of the Advisors, are inspired by the works of Frank Herbert. The towering Striders seen throughout Half-Life 2 and its subsequent episodes are based directly on the Martian tripods of the H. G. Wells novel The War of the Worlds, where Martians invade Victorian England, using the tripods as their main "weapon". The name "Combine" itself is a tribute to Ken Kesey's novel One Flew Over the Cuckoo's Nest, which features a collection of authorities which mechanistically manipulate and process individuals. During Half-Life 2's development, various concepts for Combine non-player characters were cut. Female Combine Assassins, similar to black ops Assassins featured in the first game, were planned but later abandoned, although they appear in the Half-Life 2: Survivor arcade game. Another non-player character, the Cremator, was conceptualized as a Combine laborer who cleaned the streets of bodies after a battle with a flamethrower. Although removed from the game, its head was featured on a desk in Eli Vance's laboratory in Black Mesa East. Other cuts included a variety of alien Combine soldiers that would have complemented the transhuman soldiers in the game and a number of synthetic combat machines. Many of Half-Life 2's Combine characters went through repeated redesigns; the Combine Overwatch soldier was subjected to at least twelve before the final appearance was decided.
Sources: en.wikipedia.org
=== Muscle mass === Researchers are still debating whether the more noticeable muscles are larger in size as well. It should be clarified, though, that muscle mass is not the same as muscle strength. Some say that human growth hormone will build muscle mass through raised insulin-like growth factors levels leading to heightened protein synthesis without any side effects while other researchers argue that there have been no such findings on young healthy adults. The second argument is more supported by research discoveries that HGH affects muscle protein synthesis no differently than a placebo does.
== Human rights abuses == Various groups have claimed that SWAPO committed serious human rights abuses against suspected spies during the independence struggle. Since the early 21st century, they have pressed the government more strongly on this issue. Breaking the Wall of Silence (BWS) is one of the groups founded by people who were detained by SWAPO during the war and abused during interrogations. In 2004, BWS alleged that "In exile, hundreds of SWAPO dependants and members were detained, tortured and killed without trial." SWAPO denies serious infractions and claims anything that did happen was in the name of liberation. Because of a series of successful South African raids, the SWAPO leadership believed that spies existed in the movement. Hundreds of SWAPO cadres were imprisoned, tortured and interrogated.
=== As a fungicide and herbicide === Copper sulfate has been used for control of algae in lakes and related fresh waters subject to eutrophication. It "remains the most effective algicidal treatment". Bordeaux mixture, a suspension of copper(II) sulfate (CuSO4) and calcium hydroxide (Ca(OH)2), is used to control fungus on grapes, melons, and other berries. It is produced by mixing a water solution of copper sulfate and a suspension of slaked lime. A dilute solution of copper sulfate is used to treat aquarium fishes for parasitic infections, and is also used to remove snails from aquariums and zebra mussels from water pipes. Copper ions are highly toxic to fish. Most species of algae can be controlled with very low concentrations of copper sulfate.
=== Visualization === The three most popular ways of visualizing the alpha-helical secondary structure of oligopeptide sequences are (1) a helical wheel, (2) a wenxiang diagram, and (3) a helical net. Each of these can be visualized with various software packages and web servers. To generate a small number of diagrams, Heliquest can be used for helical wheels, and NetWheels can be used for helical wheels and helical nets. To programmatically generate a large number of diagrams, helixvis can be used to draw helical wheels and wenxiang diagrams in the R and Python programming languages.
== Personal life == In the early 1990s, Staley enrolled in several rehab programs, but he failed to stay clean for long. At one point, the other members of Alice in Chains flew to Los Angeles for weekly therapy at Staley's rehab. During the Dirt tour, Alice in Chains' manager, Susan Silver, hired bodyguards to keep Staley away from people who might try to pass him drugs, but he ended up relapsing on alcohol and drugs during the tour. Screaming Trees' Mark Lanegan recalled partying with Staley on tour and said that, "off stage, it was an insane, dark, drug and alcohol-fuelled frat party from start to finish, with Layne [Staley] and I raising hell, behaving like teenagers, staying up for days on end. We partook of whatever drugs came our way. Heroin, cocaine, painkillers, anything." Kurt Cobain's death in April 1994 scared Staley into temporary sobriety, but soon he was back into his addiction. Alice in Chains' managers turned down lucrative touring possibilities and kept the band off the road, hoping that would help Staley. Pearl Jam lead guitarist Mike McCready also tried to help Staley by inviting him to his side project, Mad Season. McCready had hoped that playing with sober musicians would encourage Staley. On October 29, 1996, Staley's former fiancée, Demri Lara Parrott, died of a drug overdose. Staley was placed on a 24-hour suicide watch, according to NME, which quoted a friend saying Staley was taking Parrott's death "extremely badly" and had fallen into a deep depression. Lanegan told Rolling Stone in 2002, "He never recovered from Demri's death.
Sources: en.wikipedia.org
== Universities == According to the 2020 QS World University Rankings, Chulalongkorn University (CU) was ranked 247th in the world and earned the top ranking in Thailand for the seventh consecutive year. Also ranked were Mahidol University (314th), and Chiang Mai University and Thammasat University (both in the 601–650 tranche), and four other Thai universities in the 801–1,000 tranche. The Times Higher Education Asia University Rankings 2018 ranked Mahidol University as the top Thai institution. It ranked 97 of some 350 universities (1=best; 350=lowest). King Mongkut's University of Technology Thonburi was ranked 116, Chulalongkorn University 164, and Suranaree University of Technology 168. Thailand had no other universities in the top 200. Chulalongkorn University was ranked number one in Thailand and 45th in Asia in 2016. Mahidol University was ranked the top Thai university among the top 200 Asian (including Middle Eastern) universities in 2016 by Times Higher Education Asia University Rankings 2016.
The species was named by ornithologist John Latham in 1790 based on a specimen from the Sydney area of Australia, a country which was known as New Holland at the time. He collaborated on Phillip's book and provided the first descriptions of, and names for, many Australian bird species; Dromaius comes from a Greek word meaning "racer" and novaehollandiae is the Latin term for New Holland, so the name can be rendered as "fast-footed New Hollander". In his original 1816 description of the emu, the French ornithologist Louis Pierre Vieillot used two generic names, first Dromiceius and later Dromaius. It has been a point of contention ever since as to which name should be used; the latter is more correctly formed, but the convention in taxonomy is that the first name given to an organism stands, unless it is clearly a typographical error. Most modern publications, including those of the Australian government, use Dromaius, with Dromiceius mentioned as an alternative spelling.
=== Autism === An intranasal formulation of carbetocin was also under development for the treatment of autism, but development was discontinued as well. It was variously developed by Nastech Pharmaceutical Company, Retrophin (Travere Therapeutics), Marina Biotech, and Cypress Bioscience and had the developmental code name CYP-2001. The drug reached phase 1 trials for autism prior to being discontinued.
=== Placement of the pumpkin === Prior to October 8, 1997, an unknown individual or group of individuals placed a pumpkin on the lightning rod of McGraw Tower at Cornell University, 173 feet (53 m) in the air. The pumpkin was nearly 2 feet (61 cm) in diameter, and university spokesman David Brand would later state that the pumpkin was carved to fit the rod. They likely climbed up the tower's staircase which was open to the public at specified times, moved through the tower's bell cage without tripping the wires that would sound the chimes, cut a lock near the roof, emerged through a small service hatch at the bottom of the roof, and climbed 20 feet (6.1 m) up the steeply pitched steel roof of the tower to do so.
=== Regulation of gene expression === The activated IRS-1 acts as a secondary messenger within the cell to stimulate the transcription of insulin-regulated genes. First, the protein Grb2 binds the P-Tyr residue of IRS-1 in its SH2 domain. Grb2 is then able to bind SOS, which in turn catalyzes the replacement of bound GDP with GTP on Ras, a G protein. This protein then begins a phosphorylation cascade, culminating in the activation of mitogen-activated protein kinase (MAPK), which enters the nucleus and phosphorylates various nuclear transcription factors (such as Elk1).
Sources: en.wikipedia.org
Both molecules activate the same receptor, GHSR-1a, but they share little sequence identity. Ghrelin is a 28-amino-acid hormone carrying a distinctive acyl modification, whereas ipamorelin is a short synthetic peptide. The shared target explains overlapping endocrine effects, while the different structures account for differences in metabolic stability and receptor selectivity.
Early animal and human studies reported growth hormone release at levels that produced small changes in cortisol, prolactin and adrenocorticotropic hormone. That contrast with older secretagogues gave rise to the selectivity label. The observation is consistent across several reports but rests on a limited number of small studies.
Plasma peptidases cleave the molecule into smaller fragments, and reported half-lives in human studies are on the order of a couple of hours. The identity and activity of individual breakdown products have not been fully mapped. Questions about tissue-level clearance remain open.
It is a synthetic pentapeptide belonging to the growth hormone secretagogue family. Its principal characterized target is the ghrelin receptor, also called GHS-R1a. The molecule contains non-natural amino acids and an amidated C-terminus.