reconstitution 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 2026-01-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Purity assessment for this peptide relies mainly on reversed-phase high-performance liquid chromatography. A C18 column with a water-acetonitrile gradient containing trifluoroacetic acid separates the target from truncated sequences and oxidation products. Detection near 214 nm exploits the amide backbone, while the aromatic side chains allow additional monitoring close to 280 nm. Reported purity values depend on the method, so a certificate of analysis carries weight only when gradient, column and integration parameters are given.
Mass spectrometry confirms identity and reveals structural deviations that chromatography alone can miss. Positive-mode electrospray ionisation generally yields multiply charged ions whose deconvoluted mass is checked against the theoretical value. Amino acid analysis, and enzymatic digestion with subsequent fragment mapping, provide independent confirmation of sequence and of the terminal amide. Analysts take care to separate the target from deletion sequences, which may differ by one residue and therefore by only a small mass increment.
The lyophilised solid is normally held at -20 °C or colder, shielded from light and moisture. Stability in that state is measured in years, although shelf life depends on residual water content and the container seal. Once dissolved, the peptide is more fragile: aqueous solutions are commonly kept at 2-8 °C and used within days to weeks, and repeated freeze-thaw cycling is avoided. Strongly acidic or basic conditions accelerate hydrolysis, and prolonged exposure to them can strip the terminal amide.
| 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 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.
One distinguishing feature reported in animal studies is selectivity. Ipamorelin stimulated growth hormone release with limited elevation of adrenocorticotropic hormone or cortisol compared with earlier secretagogues such as GHRP-6. This pattern has been described as more selective for the growth hormone axis. The finding comes mainly from preclinical work, and the degree to which it holds across species and doses is not fully settled. Reports also describe effects on gastric motility in animal models, suggesting activity outside the pituitary, though the clinical relevance of this observation is uncertain.
Lyophilized material is generally stored frozen and protected from light and moisture. Typical recommendations place dry powder at temperatures well below freezing, while reconstituted solutions are kept cold and used within a defined window. Repeated freezing and thawing should be avoided because it can promote aggregation and loss of material. The choice of solvent matters as well; compatibility with the intended diluent should be checked before preparation. These handling practices aim to preserve both the quantity and the integrity of the peptide.
Verification of identity and purity relies on analytical methods used across peptide chemistry. Reverse-phase high-performance liquid chromatography separates components by hydrophobicity and provides a purity estimate. Mass spectrometry confirms molecular mass and helps detect modifications. Together these techniques give complementary information about whether a sample matches its expected structure. Results depend on method parameters and reference standards, so reported purity values are meaningful only when the analytical conditions are stated. Consistency between laboratories requires comparable protocols and well-characterized reference materials.
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。
== Research == Quadrupole theory (stability, acceptance and transmission of multipole RF and electrostatic driven devises), molecular gas dynamics, and supersonic beam expansion into vacuum. Development of the DRC Collision/reaction cell. Development of mass spectrometry (CyTOF), including fundamentals of operation and design of different MS instrumentation.
a metal, such as palladium or nickel, in bulk, thin films or powder; and deuterium, hydrogen, or both, in the form of water, gas or plasma. Electrolysis cells can be either open cell or closed cell. In open cell systems, the electrolysis products, which are gaseous, are allowed to leave the cell. In closed cell experiments, the products are captured, for example by catalytically recombining the products in a separate part of the experimental system. These experiments generally strive for a steady state condition, with the electrolyte being replaced periodically. There are also "heat-after-death" experiments, where the evolution of heat is monitored after the electric current is turned off. The most basic setup of a cold fusion cell consists of two electrodes submerged in a solution containing palladium and heavy water. The electrodes are then connected to a power source to transmit electricity from one electrode to the other through the solution. Even when anomalous heat is reported, it can take weeks for it to begin to appear—this is known as the "loading time," the time required to saturate the palladium electrode with hydrogen (see "Loading ratio" section). The Fleischmann and Pons early findings regarding helium, neutron radiation and tritium were never replicated satisfactorily, and its levels were too low for the claimed heat production and inconsistent with each other.
=== Czech Republic === After joining NATO, the Army of the Czech Republic developed a combat ration known as the BDP (Czech: Bojová Dávka Potravin). The BDP comes in two versions, type I and II, each holding two ready-to-eat main courses packed in large foil "cans" (beef roast with rice, pork goulash with potato, spicy risotto, pork with carrots and vegetables, etc.), a small plastic cup of lunch meat spread, cheese spread, hard bread, cookies, jam, instant coffee, tea bags, fruit-flavored multivitamin drink tablets, vitamin C enriched fruit drink powder, a chocolate bar, sugar, salt, chewing gum, wet napkins, paper towels, a plastic bag, and a menu and instruction sheet. A modified version of the BDP known as the KDP (Czech: Konzervovaná Dávka Potravin) is also used. This contains the same items as the BDP, but adds an aluminium cup, plastic utensils, a folding stove with fuel tablets and matches, and soap.
Sources: en.wikipedia.org
The cyanogenic glycosides in some white clover (Trifolium repens) varieties may influence the Se requirement, presumably because of cyanide from the aglycone released by glucosidase activity in the rumen and inactivation of glutathione peroxidases by the effect of absorbed cyanide on the glutathione moiety. In areas where selenium deficiency in livestock is a concern, selenium (as selenite) may be supplemented in feed. Certain countries, e.g., the US and Canada, regulate such supplementation. Neonate ruminants at risk of WMD may be administered both Se and vitamin E by injection; some of the WMD myopathies respond only to Se, some only to vitamin E, and some to either.
=== Catalysis === Ion exchange resins are used in organic synthesis, e.g. for esterification and hydrolysis. Being high surface area and insoluble, they are suitable for vapor-phase and liquid-phase reactions. Examples can be found where basic (OH−-form) of ion exchange resins are used to neutralize of ammonium salts and convert quaternary ammonium halides to hydroxides. Packed-bed reactors with continuous feed enable high turnover numbers and scale-up for industrial synthesis but may prove costly due to catalyst replenishment costs. Furthermore, acidic (H+-form) ion exchange resins have been used as solid acid catalysts for scission of ether protecting groups. and for rearrangement reactions.
cuvette A type of small container used in spectroscopy experiments, usually made of plastic, glass, or quartz and designed to hold a sample (typically a liquid) for measurement inside a spectrometer. Cuvettes should be as clean and transparent as possible to minimize interference with the beams of light on which spectroscopic techniques rely.
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.
Results are most often expressed as a percentage of total peak area from a reversed-phase separation. That figure reflects the detection wavelength, gradient and integration choices used by the laboratory. Two valid certificates can therefore quote different values for the same material without either being incorrect.