The short version of pentapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-12 and is reviewed periodically as new material appears.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
The molecule contains five residues, including alpha-aminoisobutyric acid, D-2-naphthylalanine, and D-phenylalanine, and it ends in a lysine amide. Non-natural and D-configured residues make the chain less susceptible to common peptidases, which helps explain its resistance to rapid breakdown. Its molecular formula is C38H49N9O5, corresponding to a free-base mass near 711.9 daltons. The C-terminal amide removes a negative charge and is a recurring feature in receptor-active peptides of this family. These structural choices are usually discussed as the basis for its selectivity profile.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
在 GHS 家族中，早期肽类如 GHRP-6 与 GHRP-2 会同时促进生长激素、皮质醇与催乳素的释放，并明显增加食欲。Ipamorelin 在动物与早期人体研究中表现出对生长激素释放的相对选择性，对上述其他激素的影响较小。这种差异通常归因于受体结合模式与下游信号偏向的不同，而完整的分子解释仍有待补充。需要区分的是，选择性是研究观察中的相对程度，并非绝对界限。
从用途定位看，ipamorelin 目前主要以研究用肽的身份被讨论，未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用，不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小，因此对其效应强度与一致性的描述应保持谨慎。
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.
The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.
Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.
Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.
The blast furnace is loaded with iron ores, usually hematite Fe2O3 or magnetite Fe3O4, along with coke (coal that has been separately baked to remove volatile components) and flux (limestone or dolomite). "Blasts" of air pre-heated to 900 °C (sometimes with oxygen enrichment) is blown through the mixture, in sufficient amount to turn the carbon into carbon monoxide:
=== Other haematology apparatus === Automatic erythrocyte sedimentation rate (ESR) readers, while not strictly analysers, do preferably have to comply to the 2011-published CLSI (Clinical and Laboratory Standards Institute) "Procedures for the Erythrocyte Sedimentation Rate Test: H02-A5 and to the ICSH (International Council for Standardization in Haematology) published "ICSH review of the measurement of the erythrocyte sedimentation rate", both indicating the only reference method, being Westergren, explicitly indicating the use of diluted blood (with sodium citrate), in 200 mm pipettes, bore 2.55 mm. After 30 or 60 minutes being in a vertical position, with no draughts and vibration or direct sunlight allowed, an optical reader determines how far the red cells have fallen by detecting the level.
A thermostat operates by switching heaters or air-conditioners on and off in response to the output of a temperature sensor. Cruise control adjusts a car's throttle in response to changes in speed. An autopilot operates the steering controls of an aircraft or ship in response to deviation from a pre-set compass bearing or route. Process control systems in a chemical plant or oil refinery maintain fluid levels, pressures, temperature, chemical composition, etc. by controlling heaters, pumps and valves. The centrifugal governor of a steam engine, as designed by James Watt in 1788, reduces the throttle valve in response to increases in the engine speed, or opens the valve if the speed falls below the pre-set rate.
=== Oleato coffee === In February 2023, Starbucks announced it would introduce a line of coffee drinks made with extra virgin olive oil, including lattes, shaken espresso, and cold brews. This would not be a limited-time offering, but rather "'one of the biggest launches we’ve had in decades,'" according to Brady Brewer, the company's chief marketing officer. The goal was to create a new category of beverage. Unlike other drinks, this came about because of the habits of then-CEO Howard Schultz, who was introduced to consuming a teaspoon of olive oil each day by an olive oil producer he met in Sicily. The drinks were initially available in Italy and later expanded to stores in Southern California in spring 2023 and then the UK, Middle East, and Japan later the same year. After its launch, CNN reported some customers reported digestive distress after drinking the beverages. In January 2024, the company said it would introduce the beverages nationwide in the US as well as in Canada, France, and China. The Oleato beverages were permanently discontinued in November 2024.
The receptors for the RLN/INSL peptides are collectively called "Relaxin family peptide receptors (RXFPs)". In humans there are four RXFP receptors (RXFP1-4) all of which are cell membrane-associated and coupled to G-proteins (known as G protein-coupled receptors or GPCRs). There are two distinct families of RXFPs: RXFP1 and RXFP2 are evolutionarily related to the receptors of follicle-stimulating hormone (FSH) and LH, and are the cognate receptors for RLN and INSL3 respectively in humans. On the other hand, RXFP3 and RXFP4 are related to somatostatin and, in humans, are the cognate receptors for RLN3 and INSL5. There is evidence that some relaxin hormones may also be able to interact with glucocorticoid-type nuclear receptors, which float freely between the cytoplasm and nucleoplasm.
Sources: en.wikipedia.org
Ropinirole is metabolized primarily by cytochrome P450 CYP1A2 to form two metabolites; SK&F-104557 (N-Despropyl Ropinirole) and SK&F-89124, both of which are renally excreted, and at doses higher than clinical, is also metabolized by CYP3A4. At doses greater than 24 mg, CYP2D6 may be inhibited, although this has been tested only in vitro. 7-Hydroxyropinirole (SK&F-89124), a major metabolite of ropinirole in rats but minor metabolite in humans (<5% of dose), is a highly potent dopamine receptor agonist with antiparkinsonian activity similarly to ropinirole. It has been reported to be 30-fold more potent than ropinirole as a dopamine D2 receptor agonist in vitro. However, ropinirole and 7-hydroxyropinirole were equipotent in terms of antiparkinsonian activity in rodents in vivo. 7-Hydroxyropinirole is said to be the only metabolite of ropinirole known to possess significant dopaminergic activity in vivo, although other ropinirole metabolites have also been found to have dopaminergic activity.
== See also == Category:Longest words by language Morphology (linguistics) List of long place names Wikipedia:Unusual place names#Long place names Longest English sentence Coxeter group – mathematical concept whose entities are sometimes called words Hubert Blaine Wolfeschlegelsteinhausenbergerdorff Sr., a German-born American typesetter who held the record for the longest personal name ever used (about 666 letters) Musical works with long names in English: But What About the Noise ..., a percussion composition by John Cage, 1985 The Best... Album in the World...Ever!, a compilation album series from Circa Records with the lengthiest album name prior to 1999 When the Pawn..., an album by Fiona Apple (444 characters, 1999) The Boy Bands Have Won, an album by Chumbawamba (865 characters, 2008) List of longest names in Taiwan
=== Escalating Security Tensions (June 2026) === Following the reinstatement of the pre-war regional council and the formation of a parallel executive structure, political tensions in Tigray continued to intensify throughout June 2026. Reports of military recruitment campaigns emerged from multiple parts of the region, while growing concerns were raised regarding the possibility of renewed armed confrontation between regional and federal actors. At the same time, the Legal Standing Committee of the reinstated council prepared a draft wartime mobilization proclamation that would establish a legal framework for compulsory military mobilization and wartime administration. The proposal generated debate among legal experts, journalists, opposition figures, and human-rights organizations regarding its implications for civil liberties and freedom of expression.
(along with 31 other leaders in the sustainable food movement) signed an open letter of support for the CIW's campaign, stating that, "If Chipotle is sincere in its wishes to reform its supply chain, the time has come to work with the Coalition of Immokalee Workers as a true partner in the protection of farmworkers rights." In September 2009, Chipotle announced that it would sidestep partnership with the CIW and instead work directly with East Coast Growers and Packers to increase wages for its tomato pickers. Ells framed the dispute as a fundamental issue of control, stating that, "the CIW wants us to sign a contract that would let them control Chipotle's decisions regarding food in the future". In October 2012, Chipotle signed an agreement with the CIW to improve working conditions. In January 2015, Chipotle pulled carnitas from its menu in a third of its restaurants; company officials cited animal welfare problems at one of the suppliers, found during a regular audit, as the reason. Subsequently, a false rumor spread online claiming it was done to appease Muslims who consider pork to be unclean, leading to some protests on social media. The company still uses antibiotic-free and hormone-free steak in its restaurants, despite being briefly forced to "serve beef that is not naturally raised" during the summer of 2013, posting an in-store notice each time that occurred. Roberto Ferdman of The Washington Post opined that Chipotle's stated mission to sell "food with integrity" may be "untenable" if meat producers continue to breach Chipotle's ethical standards.
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
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.