pentapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
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.
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
| 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 |
Lyophilized material is generally held at minus twenty degrees Celsius or lower, protected from moisture and light. Repeated excursions to room temperature cause condensation inside the vial and gradual moisture uptake, both of which shorten shelf life. Containers should be allowed to equilibrate before opening so that water does not condense on the solid. Dividing a batch into single-use aliquots reduces freeze-thaw cycling. Solid peptide handled this way is usually considered stable for months to years, while the same material in solution degrades on a much shorter timescale.
Common solvents for laboratory work include water, buffered saline, and dimethyl sulfoxide. Once dissolved, the peptide is exposed to hydrolysis and oxidation, and alkaline conditions accelerate breakdown. Low-binding plasticware and the addition of a carrier protein reduce losses to container surfaces, which can otherwise be substantial at low concentrations. Solutions are typically kept cold and used within days. Investigators working with the compound generally prepare fresh working dilutions rather than storing dilute stocks, and they avoid repeated warming of the same vial.
Reversed-phase high-performance liquid chromatography is the standard method for purity assessment, most often on a C18 column with a water and acetonitrile gradient and trifluoroacetic acid or formic acid as an ion-pairing agent. Mass spectrometry by electrospray or matrix-assisted laser desorption confirms the expected mass and reveals truncated or modified sequences. Amino acid analysis and sequencing provide orthogonal structural evidence. Typical impurities include deletion sequences, oxidized products, and dimeric species. Detection wavelength, usually 214 or 220 nanometers, should be reported because response factors differ between peptides.
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor, also called the ghrelin receptor or GHS-R1a. Binding to this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to growth hormone release. The effect is mediated through phospholipase C and calcium mobilization rather than through the cyclic AMP pathway used by growth hormone releasing hormone. The two pathways are complementary, and combined stimulation produces a larger response than either alone.
Compared with other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.
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, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.
=== Success === SOLAR was known for several others who enjoyed success, including: The Whispers, Dynasty, Lakeside, Midnight Star, Klymaxx, Calloway, Carrie Lucas, Collage and The Deele — which introduced singer/songwriter/producer Kenneth "Babyface" Edmonds and future music executive Antonio "L.A." Reid. Griffey had always believed in giving new talents the opportunity to create and develop their craft, and he was introduced to songwriters/producers Jimmy Jam and Terry Lewis by his A & R rep Dina R. Andrews (Dina Andrews Management Inc) who was the team's first manager, Reggie and Vincent Calloway, and Leon F. Sylvers III. The "SOLAR sound" was a collective effort, with artists working on each other's sessions and artists encouraged to be creative. Sylvers became SOLAR's house producer in 1978 and his signature basslines and productions helped mould the hit sound of SOLAR, which is funky, progressive dance music infused with soul and disco.
== Habitat and range == C. brunneus are found in Europe, north Africa, and temperate Asia. They prefer dry habitats. They are present in higher numbers in heathland areas compared to agricultural areas. This can be explained by the difference in sward height in the two areas. C. brunneus prefer habitats with sward heights of 100 to 200 mm and fine leaved grass species. In fact a positive correlation between C. brunneus and both Agrostis species and Festuca species exists. Fine leaved grass species and taller sward heights occur more commonly in heathlands where less human alteration of the land occurs compared to agricultural sites. Sward height also influences abundance. A greater number of C. brunneus are found in taller swards although some scientific literature suggests C. brunneus thrives in wastelands. Vertebrate grazing also influences C. brunneus density by directly influencing sward height. Ungrazed areas have higher densities of C. brunneus than grazed areas. Vertebrate grazing is thought to alter plant hormones two of which are known to effect fecundity, abscisic acid, and gibberellins. Additionally grazing results in the production of proteinase inhibitors in plants and the alteration of nitrogen levels. In areas that experience less vertebrate grazing C. brunneus have increased rates of development, higher adult weights, and increased fecundity.
In 2016, she co-starred in the thriller American Romance, and had a supporting role in the psychological horror film Jack Goes Home. Also in 2016, she provided the English voice of Kiwako Seto in the video game Let It Die. American Romance, Jack Goes Home and Let It Die served as her final acting credits.
Homochirality is a uniformity of chirality, or handedness. Objects are chiral when they cannot be superposed on their mirror images. For example, the left and right hands of a human are approximately mirror images of each other but are not their own mirror images, so they are chiral. In chemistry, chirality is a geometric property of some compounds and ions. These compounds exist in two different chiral conformations, enantiomers, often described as the left-handed and right-handed isomers of a compound (denoted by L- (levorotatory to the left) and D- (dextrorotatory to the right), respectively, from how chiral molecules rotate plane-polarized light). The term homochiral is used to describe enantiopure samples of substances in which all the constituents are the same enantiomer. Enantiomers have the same chemical properties in an achiral environment, so abiotic chemical processes typically produce racemic mixtures of chiral compounds, i.e., mixtures containing equal amounts of L- and D-isomers. However, many biologically-synthesized compounds are homochiral. For example, 19 of the 20 genetically-coded proteinogenic amino acids are left-handed, with exception of the achiral glycine, and biological sugars are right-handed. Many theories have been proposed for the "function" of homochirality in nature: it may be a form of information storage and may reduce entropy barriers in the formation of large organized molecules. It has been experimentally verified that amino acids form large aggregates in larger abundance from enantiopure samples than from racemic ones.
The term narcotic (, from ancient Greek ναρκῶ narkō, "I make numb") originally referred medically to any psychoactive compound with numbing or paralyzing properties. In the United States, it has since become associated with opiates and opioids, commonly morphine and heroin, as well as derivatives of many of the compounds found within raw opium latex. Legally speaking, the term "narcotic" may be imprecisely defined and typically has negative connotations. When used in a legal context in the U.S., a narcotic drug is totally prohibited, such as heroin, or one that is used in violation of legal regulation (in this word sense, equal to any controlled substance or illicit drug). In the medical community, the term is more precisely defined as a synonym of opioids and generally does not carry the same negative connotations. Statutory classification of a drug as a narcotic often increases the penalties for violation of drug control statutes. For example, although U.S. federal law classifies both cocaine and amphetamines as "Schedule II" drugs, the penalty for possession of cocaine is greater than the penalty for possession of amphetamines because cocaine, unlike amphetamines, is classified as a narcotic. Research acknowledges that alcohol can have similar effects to narcotics in head or trunk trauma situations.
Sources: en.wikipedia.org
== Mechanism of action == Like all opioid drugs, ADL-5859 activates opioid receptors, but where as traditional opioids (such as oxycodone) activate the three main receptors (mu, delta, and kappa), ADL-5859 appears to be selective and only activates the delta receptor. with a Ki of 20 nM
A liver biopsy (tissue examination) is the only test widely accepted (gold standard) as definitively diagnosing and distinguishing MASLD and MASH from other forms of liver disease. It can be used to assess the severity of inflammation and resultant fibrosis. However, since most people affected by MASLD are likely to be asymptomatic, liver biopsy presents too high a risk for routine diagnosis, so other methods are preferred, such as liver ultrasonography or liver MRI. For young people, guidelines recommend liver ultrasonography, but biopsy remains the best evidence. Liver biopsy is also the gold standard to detect hepatic fibrosis and assess its progression. Routine liver function blood tests are not sensitive enough to detect MASLD, and biopsy is the only procedure that can reliably differentiate MASLD from MASH. There are several liver biopsy techniques available to obtain liver tissue. Percutaneous liver biopsy remains the most common practice. Biopsies can also be performed via the transvenous route, either during surgery or by laparoscopy, especially for people with contraindications to a percutaneous approach. The liver biopsy can also be image-guided, in real-time or not, which is recommended for some clinical situations, such as people with known liver lesions, previous intra-abdominal surgery who may have adhesions, a small liver that is difficult to percuss, people with obesity, and people with evident ascites.
=== In popular culture === The movie A Civil Action, starring John Travolta, was based on the Grace groundwater contamination lawsuits in Woburn, Massachusetts. The PBS television show P.O.V., which highlights independent films, in August 2007 premiered the movie Libby, Montana which documents the thousands of people in Libby, Montana, that have been exposed to and are suffering the effects of asbestos exposure. The show also discusses the criminal indictments of many Grace executives for covering up asbestos related illnesses and deaths. PBS also aired Dust to Dust, a documentary produced by Michael Brown Productions, Inc. in 2002. Dust to Dust reports on the more than 200 people who have died from asbestos exposure in Libby, Montana. The film focuses on the plights of several of these individuals and the damage done over almost 30 years while the mine was operated by W. R. Grace. NPR aired a piece on All Things Considered discussing the criminal charges against W. R. Grace. A U.S. attorney general alleges that the company and managers of the mine in Libby, Montana, knew about the dangers of the asbestos they were dumping into the air for over 20 years. On February 19, 2008, the NPR-produced radio show Here and Now broadcast a story about the film Libby, Montana, which details the asbestos contamination in the town of that name. On April 22, 2009, the television and radio program Democracy Now! broadcast two segments on the trial of W. R. Grace and some of its employees related to the asbestos contamination in Libby, Montana.
BBC News reports that Paul Powlesland has become the first juror to swear an oath on a river after doing so at Snaresbrook Crown Court. New powers under the Victims and Prisoners Act come into force that prevent prisoners convicted of the most serious offences in England and Wales from marrying while in custody. One of the first uses of the new legislation is to prevent convicted murderer Levi Bellfield from entering into a civil partnership with his girlfriend. Details are published of the autumn programme of COVID-19 vaccination, which will be broadly the same as 2023 with the vaccine offered to all adults aged 65 and over, as well as certain health and social care staff, older care home residents and people in clinical risk groups. 2024 riots: Rioting breaks out in Sunderland, where protestors clash with police outside a mosque. 3 August – The BBC removes a video promoting Children in Need 2018 from its website after it emerges the video features the suspect in the 2024 Southport stabbing. 4 August – Starmer condemns the ongoing "far-right thuggery" around the UK and says those involved "will regret it", as the number of people arrested in relation to the disorder exceeds 140. At least 10 police officers are injured at the Holiday Inn Express Hotel in Rotherham, with one left unconscious after a head injury, while others have broken bones. 5 August 2024 United Kingdom riots: Starmer holds an emergency COBRA meeting of ministers, civil servants, the police and intelligence officers in response to the rioting of recent days.
=== Names === Methylephedrine is the generic name of the drug and its BANTooltip British Approved Name. In the case of the hydrochloride salt, its generic name is methylephedrine hydrochloride and this is its BANMTooltip British Approved Name. Brand names of methylephedrine include Metheph, Methy-F, and Tybraine, among others.
Sources: en.wikipedia.org
=== Oakley et al. (2013) === In 2013 combined study of morphology, including fossils, and molecular data, including expressed sequence tag, mitochondrial genome, nuclear genome, and ribosomal DNA data, Oakley et al. obtained support for three pancrustacean clades: Oligostraca (Ostracoda, Mystacocarida, Branchiura, Pentastomida), Multicrustacea (Copepoda, Thecostraca, Malacostraca) and a clade they refer to as Allotriocarida (Branchiopoda, Cephalocarida, Remipedia, Hexapoda), as well as for monophyly of Ostracoda. Within Multicrustacea they obtained support for a clade they suggest the name Hexanauplia: Thecostraca + Copepoda. Relations within Allotriocarida remain uncertain: sister taxon to Hexapoda is either Remipedia, or the clade Branchiopoda + Cephalocarida, however, authors are inclined to the first version (see "Conclusion", 4), which is also consistent with von Reumont et al. (2012) results. New proposed by Oakley et al. clades are:
== Success of insulin == MacLeod was overseeing the work of Frederick Banting and Charles Best in their search for a treatment for diabetes which they had begun in May 1921. In December, when Banting and Best were having difficulties in refining the pancreatic extract, MacLeod freed Collip from his other research to enable him to join the research team. Collip's task was to prepare insulin in a more pure, usable form than Banting and Best had been able to achieve to date. In January 1922, after 14-year-old Leonard Thompson suffered a severe allergic reaction to an injection of insulin, Collip achieved the goal of preparing a pancreatic extract pure enough for Thompson to recover and to use in clinical trials. Despite Collip's breakthrough, Banting was furious as he saw that "Collip's discoveries were not a cause for celebration but a new threat". At some point between January 17 and 24, Collip and Banting reportedly had a physical altercation in the labs, supposedly when "Collip visited Banting and Best in their lab and told them that he wasn’t going to share the latest extract formulation (which may or may not have had Macleod's blessing) and that he was contemplating leaving the research team and patenting the process on his own". A colleague later lampooned this incident with a "cartoon showing Banting sitting on Collip and titled 'The Discovery of Insulin.'" Nonetheless, successful trials were soon completed and the future of insulin was assured.
According to Annex 13 of the Convention on International Civil Aviation, an aviation accident is an occurrence associated with the operation of an aircraft, which takes place from the time any person boards the aircraft with the intention of flight until all such persons have disembarked, and in which (a) a person is fatally or seriously injured, (b) the aircraft sustains significant damage or structural failure, or (c) the aircraft goes missing or becomes completely inaccessible. Annex 13 defines an aviation incident as an occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operation. A hull loss occurs if an aircraft is damaged beyond repair, is lost, or becomes completely inaccessible.
A common pathological cause for a high BMR is fever, since a rise in body temperature increases the rate of cellular metabolic reactions. It is estimated that for every degree Fahrenheit of rise in body temperature, the BMR increases by 7 percent. Thyroid disease also has a marked effect on BMR, since thyroid hormones regulate the rate of cellular metabolism. Hyperthyroidism—in which there is an increase in the production of thyroid hormones—leads to a high BMR, while hypothyroidism—in which thyroid hormones are depleted—causes a low BMR. Prolonged periods of abnormal nutrition cause an adaptive change in BMR; this helps the body to maintain a stable body weight in response to the change in food supply. In prolonged malnutrition, the BMR declines, while in prolonged overnutrition, the BMR is increased. Cancer sometimes causes an increase in BMR, perhaps because the cancer cells that form tumors have a high level of metabolic activity.
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.
不是。它属于人工合成的五肽，设计上模拟胃饥饿素受体的部分作用，但不存在于人体天然激素谱中。