A practical reference on 五肽: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Researchers at a pharmaceutical company first described it in the 1990s while screening small peptides for growth hormone releasing activity. Its chain contains five amino acid residues, two of which are non-natural building blocks, including 2-aminoisobutyric acid and a naphthylalanine derivative. The molecule was designed to act at the ghrelin receptor while avoiding several effects observed with earlier secretagogues.
在机制层面，ipamorelin 与生长激素促分泌受体 1a 型结合，该受体也介导胃饥饿素的多种效应。受体激活后，细胞内信号促进生长激素从垂体前叶释放。由于对促肾上腺皮质激素和皮质醇的刺激较弱，它被视为选择性较高的促分泌剂。这种选择性在动物模型和少量人体研究中被观察到，但人体数据仍然有限。
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 |
|---|---|---|
| Chemical class | Synthetic pentapeptide | Growth hormone secretagogue family |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Contains two non-natural residues |
| Molecular formula | C38H49N9O5 | Free base form |
| Molecular weight | 711.85 g/mol | Calculated from formula |
| Primary target | GHS-R1a ghrelin receptor | Agonist activity |
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.
Storage recommendations for ipamorelin usually focus on temperature, moisture, and light. Lyophilized powder is typically held at or below minus twenty degrees Celsius in a desiccated container protected from light. Reconstituted solutions are often aliquoted and stored at minus eighty degrees Celsius to reduce repeated freeze-thaw cycles, which can promote aggregation or degradation. The optimal buffer and pH depend on the specific assay, and no single condition applies to every experimental context. Peptide stability should be assessed with time-point measurements rather than assumed from general handling rules.
In the scientific literature, ipamorelin appears mainly in preclinical studies, receptor binding assays, and reviews of growth hormone secretagogues. Authors often discuss its selectivity profile alongside limitations such as small sample sizes, short study durations, and differences between species. Some papers examine pharmacokinetics and clearance, but human data are limited and not sufficient to define general clinical effects. Regulatory discussion treats the compound as an investigational or research substance rather than an approved therapy in most jurisdictions. Open questions include oral bioavailability, long-term endocrine effects, and whether selectivity observed in animals persists in humans.
Research peptides such as ipamorelin are commonly supplied as lyophilized powder and characterized by analytical certificates. Reversed-phase high-performance liquid chromatography is used to estimate purity by ultraviolet absorbance, while mass spectrometry confirms molecular identity and detects sequence-related impurities. Counterion content, water content, and residual synthesis reagents can affect the reported mass balance. A certificate of analysis may list a purity percentage, but that number depends on the analytical method and the definition of impurity peaks. Independent verification is often recommended because research supply chains vary in quality control practices.
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 是一种合成五肽，序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2，分子式 C38H49N9O5，游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素（GHS）家族，作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道，设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。
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。
=== COVID-19 === The pharmacokinetic boosting property of ritonavir has been successfully repurposed for the treatment of COVID-19. It is co-packaged with nirmatrelvir, a SARS-CoV-2 main protease (3CLpro) inhibitor, under the brand name Paxlovid. In this combination regimen, ritonavir has no direct activity against SARS-CoV-2; rather, it inhibits the CYP3A4-mediated metabolism of nirmatrelvir, enhancing its systemic exposure to levels sufficient to halt viral replication. Clinical trials demonstrated that this combination significantly reduced the risk of hospitalization or death in high-risk patients when administered early (within five days of symptom onset), leading to emergency use authorizations and approvals by agencies such as the US Food and Drug Administration (FDA) and the World Health Organization (WHO).
=== Diagnostic and Statistical Manual === Initially considered a subject for further research exploration, binge eating disorder was first included in the Diagnostic and Statistical Manual of Mental Disorders (DSM) in 1994, proposed a feature of an eating disorder. In 2013, it gained formal recognition as a psychiatric condition in the DSM-5. Until 2013, binge eating disorder was categorized as an Eating Disorder Not Otherwise Specified, an umbrella category for eating disorders that don't fall under the categories for anorexia nervosa or bulimia nervosa. Before DSM-5, Eating Disorder Not Otherwise Specified, which included BED, was diagnosed more often than both anorexia nervosa and bulimia nervosa. Because it was not a recognized psychiatric disorder in the DSM until 2013, it has been difficult to obtain insurance reimbursement for treatments. The disorder now has its own category under DSM-5, which outlines the signs and symptoms that must be present to classify a person's behavior as binge eating disorder. Studies have confirmed the high predictive value of these criteria for diagnosing BED. One study found that the method for diagnosing BED is for a clinician who typically diagnose using the DSM-5 criteria or taking the Eating Disorder Examination. The Structured Clinical Interview for DSM (SCID-5) takes no more than 75 minutes to complete and has a systematic approach which follows the DSM-5 criteria. The Eating Disorder Examination is a semi-structured interview that identifies the frequency of binges and associated eating disorder features.
Types include astrocytes, oligodendrocytes, microglia, and Schwann cells. Glia limitans A thin layer of astrocytic endfeet beneath the pia mater that forms part of the barrier separating the brain parenchyma from the cerebrospinal fluid. Glial scar A dense accumulation of glial cells, particularly astrocytes, that forms after central nervous system injury. It helps contain damage but can also inhibit axonal regeneration. Glioblastoma A highly aggressive and malignant brain tumor arising from glial cells. It is the most common primary brain cancer in adults and often has a poor prognosis. Glucocorticoid A class of steroid hormones released by the adrenal cortex in response to stress. They influence metabolism and have significant effects on memory and the hippocampus. Glutamate The main excitatory neurotransmitter in the brain. It is essential for learning, memory, and synaptic plasticity, but excessive levels can cause excitotoxicity. Glutamatergic Describes neurons or synapses that use glutamate as a neurotransmitter. These are the majority of excitatory synapses in the brain. Glycine An inhibitory neurotransmitter found primarily in the spinal cord and brainstem. It acts via glycine receptors and contributes to motor control and reflexes. Golgi cell A type of inhibitory interneuron in the cerebellum that regulates input from mossy fibers to granule cells via GABA release. Golgi stain A silver staining method that randomly labels a small subset of neurons in their entirety, allowing detailed study of neuronal morphology.
Wiley (1844–1930), American chemist, pure food and drug advocate Sir Geoffrey Wilkinson (1921–1996), English chemist, 1973 Nobel Prize in Chemistry Alexander William Williamson (1824–1904), English chemist, famous for Williamson ether synthesis Thomas Willson (1860–1915), Canadian chemist, discovered an economically efficient process for creating calcium carbide Richard Willstätter (1872–1942), German chemist, 1915 Nobel Prize in Chemistry Adolf Otto Reinhold Windaus (1876–1959), German chemist, 1928 Nobel Prize in Chemistry Günter Wirths (1911–2005), German chemist Georg Wittig (1897–1987), German chemist, 1979 Nobel Prize in Chemistry Friedrich Wöhler (1800–1882), German chemist, best known for his synthesis of urea William Hyde Wollaston (1766–1828), English chemist, discovered the elements palladium and rhodium Robert B. Woodward (1917–1979), American chemist, 1965 Nobel Prize in Chemistry Charles de Worms (1903–1979), English chemist and lepidopterist Charles-Adolphe Wurtz (1817–1884), Alsatian French chemist, discovered the Wurtz reaction Kurt Wüthrich (born 1938), 2002 Nobel Prize in Chemistry
Sources: en.wikipedia.org
In 1990, professional wrestling promoter Vince McMahon attempted to form his own bodybuilding organization known as the World Bodybuilding Federation (WBF). It operated as a sister to the World Wrestling Federation (WWF, now WWE), which provided cross-promotion via its performers and personalities. Tom Platz served as the WBF's director of talent development, and announced the new organization during an ambush of that year's Mr. Olympia (which, unbeknownst to organizers, McMahon and Platz had attended as representatives of an accompanying magazine, Bodybuilding Lifestyles). It touted efforts to bring bigger prize money and more "dramatic" events to the sport of bodybuilding—which resulted in its championships being held as pay-per-view events with WWF-inspired sports entertainment features and showmanship. The organization signed high-valued contracts with a number of IFBB regulars. The IFBB's inaugural championship in June 1991 (won by Gary Strydom) received mixed reviews. The WBF would be indirectly impacted by a steroid scandal involving the WWF, prompting the organization to impose a drug testing policy prior to the 1992 championship.
Simmons has said the band intended to use the name only for a few early performances until they came up with something better, but they never did. The Doobie Brothers improved their playing by performing live all over Northern California in 1970. They attracted a particularly strong following among local chapters of the Hells Angels and got a recurring gig at one of the bikers' favorite venues, the Chateau Liberté in the Santa Cruz mountains, playing there through the summer of 1975 (although some of these concerts did not include all band members and were of an impromptu nature). A set of demos, which showcased fuzz-toned dual lead electric guitars, three-part harmonies and Hartman's drumming, caught the ear of Warner Brothers' staff A & R representative and former member of '60s pop band Harpers Bizarre, Ted Templeman who eventually earned the group a contract at Warner Bros. Records before the year (1970) was out. The band's image originally reflected that of their biggest fans—leather jackets and motorcycles. Released in April 1971, their self-titled debut album departed significantly from that image and their live sound of the period. Produced at Pacific Recorders in San Mateo, the album, which failed to chart, emphasized acoustic guitars and reflected country influences. The leadoff song "Nobody", the band's first single, has surfaced in their live set several times over the ensuing decades. Most recently, this song was re-recorded and added to their 2010 album World Gone Crazy.
== Sources == Douglas, James Sholto (1975). Hydroponics: The Bengal System: with Notes on Other Methods of Soilless Cultivation. Oxford University Press. ISBN 978-0-19-560530-3. Douglas, James Sholto (1985). Advanced Guide to Hydroponics. Pelham. ISBN 978-0-7207-1571-2. OCLC 1341823405. Jones Jr., J. Benton (2016). Hydroponics. doi:10.1201/9780849331671. ISBN 978-1-4200-3770-8.
Sources: en.wikipedia.org
Macro-creatine kinase (macro-CK) is a macroenzyme, an enzyme of high molecular weight and prolonged half-life found in human serum. It is one of the most common macroenzymes. Macro-CK type 1 is a complex formed by one of the creatine kinase isoenzyme types, typically CK-BB, and antibodies; typically IgG, sometimes IgA, rarely IgM. Macro-CK type 2 is formed from mitochondrial CK polymer. Macro-CK type 1 has been associated with autoimmune and other chronic conditions. Macro-CK type 2 has been associated with malignancy. Macro-CK has been implicated as a source of interference in interpretation of medical labs.
This principle of self-determination had been declared on numerous occasions subsequent to the declaration – President Wilson's January 1918 Fourteen Points, Sykes's Declaration to the Seven in June 1918, the November 1918 Anglo-French Declaration, and the June 1919 Covenant of the League of Nations that had established the mandate system. In an August 1919 memo Balfour acknowledged the inconsistency among these statements, and further explained that the British had no intention of consulting the existing population of Palestine. The results of the ongoing American King–Crane Commission of Enquiry consultation of the local population – from which the British had withdrawn – were suppressed for three years until the report was leaked in 1922. Subsequent British governments have acknowledged this deficiency, in particular the 1939 committee led by the Lord Chancellor, Frederic Maugham, which concluded that the government had not been "free to dispose of Palestine without regard for the wishes and interests of the inhabitants of Palestine", and the April 2017 statement by British Foreign Office minister of state Baroness Anelay that the government acknowledged that "the Declaration should have called for the protection of political rights of the non-Jewish communities in Palestine, particularly their right to self-determination."
Over time, abiotic processes involving atmospheric oxygen as well as biological processes involving soil bacteria can oxidize and convert elemental sulfur to soluble compounds, which can in turn be used by microorganisms and plants. Sulfur improves the efficiency of other essential plant nutrients, particularly nitrogen and phosphorus. Biologically produced sulfur particles are naturally hydrophilic due to a biopolymer coating and are easier to disperse over the land in a spray of diluted slurry, resulting in a faster uptake by plants. The plant requirement for sulfur equals or exceeds the requirement for phosphorus. It is an essential nutrient for plant growth, root nodule formation of legumes, and immunity and defense systems. Sulfur deficiency has become widespread in many countries in Europe. Because atmospheric inputs of sulfur continue to decrease, the deficit in the sulfur input/output is likely to increase unless sulfur fertilizers are used. Atmospheric inputs of sulfur decrease because of actions taken to limit acid rains.
In 2004, John L. Helgerson, the Inspector General of the Central Intelligence Agency (CIA), conducted an internal review of the agency's pre-9/11 performance and was harshly critical of senior CIA officials for not doing everything possible to confront terrorism. According to Philip Giraldi in The American Conservative, Helgerson criticized their failure to stop two of the 9/11 hijackers, Nawaf al-Hazmi and Khalid al-Mihdhar, as they entered the United States and their failure to share information on the two men with the FBI. In May 2007, senators from both major U.S. political parties (the Republican and Democratic parties) drafted legislation to make the review public. One of the backers, Senator Ron Wyden said, "The American people have a right to know what the Central Intelligence Agency was doing in those critical months before 9/11." The report was released in 2009 by President Barack Obama.
Sources: en.wikipedia.org
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.
It acts as an agonist at the growth hormone secretagogue receptor, also known as the ghrelin receptor. Binding at pituitary somatotroph cells promotes growth hormone release.
Early studies report weaker effects on cortisol, prolactin, and appetite than compounds such as GHRP-6. The size of that difference in humans is not firmly established.
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。