A practical reference on reversed-phase HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-26 and is reviewed periodically as new material appears.
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.
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.
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 |
|---|---|---|
| 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 |
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.
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。
Analytical confirmation relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry for identity and purity assessment. Mass spectrometry distinguishes the intact molecule from truncation products and from oxidation or deamidation variants that share similar chromatographic retention. Immunoassays appear in some biological studies but can cross-react with related peptides, so they are weaker tools for identity work. Reported purity figures depend heavily on the gradient, detector, and integration method used, which complicates direct comparison between laboratories.
Research quantities of ipamorelin are typically distributed as a white to off-white lyophilized powder. The solid dissolves readily in water and in aqueous buffers, and stock solutions are commonly prepared in sterile water or a mildly acidic diluent. Adsorption to plastic and glass surfaces can reduce the concentration of very dilute solutions, so containers and transfer steps deserve attention when accurate concentrations matter. Reconstituted material is generally used promptly rather than held for extended periods.
Storage recommendations for the dry solid center on low temperature and low moisture, most often -20 °C in a sealed, desiccated container protected from light. Solutions are less stable than the powder and are usually kept cold and used within a short window. Freeze-thaw cycling is a recognized source of loss, and aliquoting before freezing is a standard precaution. These practices derive from general peptide handling principles rather than from a single published stability trial, so exact shelf lives should be treated as approximate.
==== Calcitonin gene-related peptide (CGRP) inhibitors ==== Atogepant (AGN-241689; Aquipta; MK-8031; Qulipta) – calcitonin gene-related peptide receptor (CGRPR) antagonist – migraine [131] Eptinezumab (ALD-403; Lu-AG09221; Vyepti) – monoclonal antibody against calcitonin gene-related peptide (CGRP) – migraine [132] Erenumab (Aimovig; AMG-334) – monoclonal antibody against calcitonin gene-related peptide receptor (CGRPR) – migraine [133] Fremanezumab (Ajovy; LBR-101; PF-04427429; PF-4427429; RN-307; TEV-48125) – monoclonal antibody against calcitonin gene-related peptide (CGRP) – migraine [134] Galcanezumab (Emgality; LY-2951742) – monoclonal antibody against calcitonin gene-related peptide (CGRP) – cluster headache, migraine [135] Rimegepant (BHV-3000; BMS-927711; Nurtec; Vydura) – calcitonin gene-related peptide receptor (CGRPR) antagonist – migraine [136] Ubrogepant (MK-1602; Ubrelvy) – calcitonin gene-related peptide receptor (CGRPR) antagonist – migraine [137] Zavegepant (BHV-3500; BMS-742413; PF-07930207; Vazegepant; Zavzpret) – calcitonin gene-related peptide receptor (CGRPR) antagonist – migraine [138]
=== Science and technology === Turin had an astronomical observatory used by Giovanni Plana. The scientist Amedeo Avogadro worked as a professor in Turin. Galileo Ferraris, a professor at Turin University, discovered the working principles of the electric motor during the 19th century. In modern times, Turin hosted the CSELT telco laboratory.
=== 15 December === President Zelenskyy stated that Russia should start to withdraw their troops by Christmas as a step to end the conflict. Russia responded that there would be "No Christmas Ceasefire" until Ukraine accepted its loss of territory. The Kyiv School of Economics published a report estimating that, as of November 2022, Russia's invasion had caused $136 billion in direct damage to Ukraine's infrastructure. Energy infrastructure, industry, public, and private enterprises were impacted the most. USAID delivered four excavators and over 130 generators to Kyiv for use in "boiler houses and heat supply stations" according to mayor Vitali Klitschko. The recently liberated city of Kherson was entirely without power following Russian shelling, which killed at least two people. The Kherson military administration stated that the city was hit 86 times with "artillery, MLRS, tanks, mortars and UAVs," in the past 24 hours. In the Donbas, Ukrainian forces bombarded Donetsk in the largest wave of shelling seen since 2014, according to mayor Alexey Kulemzin. Volker Türk, the United Nations High Commissioner for Human Rights, published a detailed summary of 441 killings including 8 girls during the conflict. The United States expanded its training to 500 Ukrainians each month at Germany.
=== Disinfectant === Hydrogen peroxide may be used for the sterilization of various surfaces, including surgical instruments, and may be deployed as a vapour (VHP) for room sterilization. H2O2 demonstrates broad-spectrum efficacy against viruses, bacteria, yeasts, and bacterial spores. In general, greater activity is seen against Gram-positive than Gram-negative bacteria; however, the presence of catalase or other peroxidases in these organisms may increase tolerance in the presence of lower concentrations. Lower levels of concentration (3%) will work against most spores; higher concentrations (7 to 30%) and longer contact times will improve sporicidal activity. Hydrogen peroxide is seen as an environmentally safe alternative to chlorine-based bleaches, as it degrades to form oxygen and water and it is generally recognized as safe as an antimicrobial agent by the U.S. Food and Drug Administration (FDA).
Sources: en.wikipedia.org
=== May === 1 May Coronation of Charles III and Camilla: The Royal Collection Trust confirms that Charles III will use a recycled throne chair from the coronation of George VI for his own coronation in a bid to make the event more sustainable. Camilla will use a chair from the same coronation that was used by Queen Elizabeth the Queen Mother. The 2023 World Snooker Championship concludes, with Belgium's Luca Brecel defeating England's Mark Selby 18–15 in the final to win his first world title. Brecel becomes the first player from Mainland Europe to win a World Championship. 2 May The 5% pay increase for one million NHS staff in England is signed off at a meeting between the UK government and representatives from 14 trade unions; all NHS employees but doctors and dentists are represented at the meeting. A man is arrested outside Buckingham Palace after throwing shotgun cartridges into the grounds. A controlled explosion is also carried out by police. 3 May – Coronation of Charles III and Camilla: As the Metropolitan Police release details of security measures in place, Security Minister Tom Tugendhat says that anti-monarchy groups will be allowed to protest at the coronation. 4 May 2023 United Kingdom local elections: The Conservatives incur significant losses, while Labour and the Lib Dems gain control of a number of councils from the Conservatives. The Green Party also make record gains, with over 200 councillors, and win majority control of Mid Suffolk District Council, the party's first ever council majority.
=== Post-translational modifications === Whilst detailed comparison of the MS data with predictions based on the known protein sequence may be used to define post-translational modifications, targeted approaches to data acquisition may also be used. For instance, specific enrichment of phosphopeptides may assist in identifying phosphorylation sites in a protein. Alternative methods of peptide fragmentation in the mass spectrometer, such as ETD or ECD, may give complementary sequence information.
=== Research === Sherrill develops methods, algorithms, and software for quantum chemistry. He has introduced efficient density-fitting techniques into several quantum chemistry methods, speeding up computations. His research group obtains highly-accurate results for important prototype chemical systems, and uses these results to develop computational protocols that are faster yet still accurate. Sherrill focuses on intermolecular interactions, and has published definitive studies of the strength, geometric dependence, and substituent effects in prototype interactions including π-π, CH/π, S/π, and cation-π interactions. He has developed extensions of symmetry-adapted perturbation theory (SAPT) to analyze these interactions in terms of their fundamental physical forces (electrostatics, exchange/steric repulsion, induction/polarization, and London dispersion forces). A fragment-based partitioning of SAPT allows analyses of which non-bonded contacts are most important for binding, and has been used to understand substituent effects in protein-drug binding. Sherrill has published over 200 peer-reviewed articles on these topics, and presented over 130 invited lectures, including the 2011 Robert S. Mulliken Lecture at the University of Georgia, the keynote talk for the 2015 Workshop on Control of London Dispersion Interactions in Molecular Chemistry in Göttingen, and keynote talks at the 2015 and 2016 meetings of the Southeast Theoretical Chemistry Association.
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.
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.