selectivity raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-04-29 and is reviewed periodically as new material appears.
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 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 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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with C-terminal amide |
| Average mass | Approximately 711.9 Da | Value derived from the formula |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and aqueous acetonitrile | Dissolution aided by acidic diluents |
| Common synonyms | Ipamorelin; NNC 26-0161 | Code name used in early reports |
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.
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.
The CDC defines an adult (a person aged 20 years or greater) with a body mass index (BMI) of 30 or greater as obese and an adult with a BMI of 25.0 to 29.9 as overweight. Obesity in adults is divided into three categories. Adults with a BMI of 30 to 34.9 have class 1 obesity; adults with a BMI of 35 to 39.9 have class 2 obesity; adults with a BMI of 40 or greater have class 3 obesity, which is also known as extreme or severe obesity (and was formerly known as morbid obesity). Children (persons aged 2 to 19 years) with a BMI at or above the 95th percentile of children of the same age and sex are defined as obese, and children with a BMI at or above the 85th percentile but less than the 95th percentile are defined as overweight. Compared to non-obese Americans, between 2001 and 2016, obese Americans incurred an average of $2,505 more in medical expenses annually, and in 2016, the aggregate medical cost due to obesity in the United States of America was $260.6 billion. However, some evidence suggests the lifetime cost of medical treatment for obese individuals is lower than for healthy weight individuals. This is because healthy weight people live longer statistically and tend to develop chronic diseases that need to be continually treated into old age, whereas obese people tend to die from metabolic diseases at younger ages and avoid some of those protracted medical costs.
=== Gradient === The use of a solvent gradient is very well developed in column chromatography but is less common in CCC. A solvent gradient is produced by increasing (or decreasing) the polarity of the mobile phase during the separation to achieve optimal resolution across a wider range of polarities. For example, a methanol-water mobile phase gradient may be employed using heptane as the stationary phase. This is not possible with all biphasic solvent systems, due to excessive loss of stationary phase created by disruption the equilibrium conditions within the column. Gradients may either be produced in steps, or continuously.
== Enteral formulations == Oral drugs are commonly taken as tablets or capsules. The drug (active substance) itself needs to be soluble in aqueous solution at a controlled rate. Such factors as particle size and crystal form can significantly affect dissolution. Fast dissolution is not always ideal. For example, slow dissolution rates can prolong the duration of action or avoid initial high plasma levels. Treatment of active ingredient by special ways such as spherical crystallization can have some advantages for drug formulation.
Sources: en.wikipedia.org
According to a study by Colombia's National Centre for Historical Memory, 220,000 people have died in the conflict between 1958 and 2013, most of them civilians (177,307 civilians, 40,787 fighters) and more than five million civilians were forced from their homes between 1985 and 2012, generating the world's second largest population of internally displaced persons (IDPs). The report shows that the humanitarian crisis in Colombia is extremely serious in terms of both lethal and nonlethal violence: it examines the widespread use of sexual violence against women and girls as a weapon of war, as well as the invisibility of this phenomenon. 16.9% of the population in Colombia has been a direct victim of the war. 2.3 million children have been displaced from their homes, and 45,000 children have been killed, according to national figures cited by Unicef. In total, one in three of the 7.6 million registered victims of the conflict are children, and since 1985, 8,000 minors have disappeared. As of 2016, some 1,000 children have been forcibly recruited by some of the myriad armed groups in the country, 75 have been killed, and 65 schools have been damaged by fighting since peace talks with FARC began. According to the report "Basta ya", written in 2013 by Colombia's National Centre for Historical Memory, 80% of victims affected by conflict-related violence and landmines were civilians. The report documents 1,982 massacres between 1980 and 2012. The Government also began a process of assistance, attention, and comprehensive reparation for victims of conflict.
Since the species is only found in remnant populations in the Wallacean Island, studies have examined the traits and factors that led to these certain populations' surprising persistence. A comprehensive examination of the species survival suggested that rather than being a single attribute, but the a combination including ectotherm traits, varanid biology, habitat, and anthropogenic factors.
=== Yeast and bacteria === Unlike humans, yeast and bacteria (except lactic acid bacteria, and E. coli in certain conditions) do not ferment glucose to lactate. Instead, they ferment it to ethanol and CO2. The overall reaction can be seen below:
Sources: en.wikipedia.org
As a bacteriologist, Miller was enthusiastic about the antibacterial project; he encouraged Florey to apply for a grant from the Rockefeller Foundation, and recommended to his headquarters that the request for financial support be given serious consideration. "The work proposed", Florey wrote in his application letter, "in addition to its theoretical importance, may have practical value for therapeutic purposes." Florey's application was approved, with the Rockefeller Foundation allocating US$5,000 (£1,250) per annum for five years. Florey's team already had a sample of penicillin mould; Dreyer had been given a sample of the mould in 1930 for his work on bacteriophages. He had lost interest in penicillin when he discovered that it was not a bacteriophage, but Campbell-Renton had continued to cultivate it. The team developed techniques for growing the mould on a surface of liquid Czapek-Dox medium. Most laboratory containers did not provide a large, flat area, so glass bottles laid on their sides were used. Later, specially-made containers were fabricated. As the laboratory gradually became a penicillin factory, Florey hired six women to perform the cultivation and extraction work. It had to be carried out under sterile conditions; Abraham and Chain discovered that some airborne bacteria produced penicillinase, an enzyme that destroys penicillin. Heatley and Chain tackled the problem of how penicillin could be extracted from the mould. The liquid was filtered through parachute silk to remove the mycelium, spores and other solid debris.
Pseudoacromegaly is a condition with the usual acromegaloid features but without an increase in growth hormone and IGF-1. It is frequently associated with insulin resistance. Cases have been reported due to minoxidil at an unusually high dose. It can also be caused by a selective post-receptor defect of insulin signalling, leading to the impairment of metabolic, but preservation of mitogenic, signaling. Treatment options include surgery to remove the tumor, medications, and radiation therapy. Surgery is usually the preferred treatment; the smaller the tumor, the more likely surgery will be curative. If surgery is contraindicated or not curative, somatostatin analogues or GH receptor antagonists may be used. Radiation therapy may be used if neither surgery nor medications are completely effective. Without treatment, life expectancy is reduced by 10 years; with treatment, life expectancy is not reduced.
Hydrostatic CCC or centrifugal partition chromatography (CPC) was invented in the 1980s by the Japanese company Sanki Engineering Ltd, whose president was Kanichi Nunogaki. CPC has been extensively developed in France starting from the late 1990s. In France, they initially optimized the stacked disc concept initiated by Sanki. More recently, in France and UK, non-stacked disc CPC configurations have been developed with PTFE, stainless steel or titanium rotors. These have been designed to overcome possible leakages between the stacked discs of the original concept, and to allow steam cleaning for good manufacturing practice. The volumes ranging from a 100 ml to 12 liters are available in different rotor materials. The 25-liter rotor CPC has a titanium rotor. This technique is sometimes sold under the name "fast" CPC or "high-performance" CPC.
Sources: en.wikipedia.org
It is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue. Three of its residues are non-standard amino acids, and the chain ends in an amide rather than a free acid. The molecule is small enough that it can be characterised by routine peptide analytical techniques.
It has not received marketing approval as a medicine in the United States or the European Union. Supplied material is generally described and handled as a research chemical. Regulatory treatment varies by jurisdiction, and some countries restrict growth hormone secretagogues under sports or medicines legislation.
Earlier secretagogues were associated with broader hormonal responses, including measurable changes in cortisol and prolactin. Reports on this peptide describe a narrower profile in which growth hormone release is the most prominent effect. The observation is influential because it shapes how the compound is compared with other members of the same receptor family.
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。