Everything below concerns pentapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
| 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 |
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
== See also == List of distinct cell types in the adult human body List of human microbiota(Human microbiome) Composition of the human body Lists of human genes as well as all the list of the specific organ systems:like e. g: List of skeletal muscles of the human body, List of bones of the human skeleton, Tendon, List of nerves of the human body, List of arteries of the human body, List of veins of the human body
=== Chemistry and biochemistry === Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors Organic synthesis, the chemical synthesis of organic compounds Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses Dehydration synthesis, a chemical synthesis resulting in the loss of a water molecule Biosynthesis, the creation of an organic compound in a living organism, usually aided by enzymes Photosynthesis, a biochemical reaction using a carbon molecule to produce an organic molecule, using sunlight as a catalyst Chemosynthesis, the synthesis of biological compounds into organic waste, using methane or an oxidized molecule as a catalyst Amino acid synthesis, the synthesis of an amino acid from its constituents Peptide synthesis, the biochemical synthesis of peptides using amino acids Protein biosynthesis, the multi-step biochemical synthesis of proteins (long peptides) DNA synthesis, several biochemical processes for making DNA DNA replication, DNA biosynthesis in vivo Synthesis (cell cycle) RNA synthesis, the synthesis of RNA from nucleic acids, using another nucleic acid chain as a template ATP synthesis, the biochemical synthesis of ATP
=== MSC based therapy === In certain studies, matrix-induces mesenchymal stem cell implantation showed earlier clinical improvements when compared to simple implantation of chondrocytes. The MSCs promoted cartilage regeneration in knees that had osteoarthritis and also reduced pain and disability.
Sources: en.wikipedia.org
=== After exposure === Before the administering of the vaccines and RIG, it is necessary to first clean the wound. This should be done by washing for at least 15 minutes with water and soap, and using a virucidal agent such as povidone-iodine to irrigate the wound. For individuals who have been potentially exposed to the virus, four doses over two weeks are recommended, as well as an injection of rabies immunoglobulin with the first dose. This is known as post-exposure vaccination. For people who have previously been vaccinated, only two doses of the rabies vaccine are required. However, vaccination after exposure is neither a treatment nor a cure for rabies; it can only prevent the development of rabies in a person if given before the virus reaches the brain. Because the rabies virus has a relatively long incubation period, post-exposure vaccinations are typically highly effective.
=== Relations with Tibet === In the fall of 1933, the 13th Dalai Lama sent an ultimatum to Liu Wenhui stating that Tibet would launch another attack if the 24th Army did not retreat further east. The ultimatum was not followed up because of the Lama's death on 17 December. In the wake of the ensuing political instability within the region, Liu cabled Nanjing for an expeditionary force to restore Chinese control over the entirety of Tibet. However, Dai Jitao and other close advisors to Chiang Kai-shek chose a more conciliatory policy and urged restraint on 23 December, which Liu Wenhui again ignored. Here, historian James Leibold speculates that Liu would probably have seized Lhasa had it not been for his untimely defeat at the hands of his nephew. In 1934, the new Tibetan government of Jamphel Yeshe Gyaltsen was ready to pursue peace with the central government, as the war with Liu had drained the monasteries' resources and driven up the price of Chinese tea. Chiang dispatched General Huang Musong on a diplomatic mission to Lhasa, with the aim of getting Tibet to accept Chinese sovereignty in exchange for broad autonomy. This mission, although accepted by the Kashag, was foiled when Liu Wenhui met with Huang in Chengdu and urged a hard line on the border issue. This was anathema to the Tibetans who wanted a demilitarized buffer zone in Xikang to protect from Liu Wenhui's army.
Different countries have different regulatory requirements and enforcement abilities. An estimated 40% of all clinical trials now take place in Asia, Eastern Europe, and Central and South America. "There is no compulsory registration system for clinical trials in these countries and many do not follow European directives in their operations", says Jacob Sijtsma of the Netherlands-based WEMOS, an advocacy health organisation tracking clinical trials in developing countries. Beginning in the 1980s, harmonization of clinical trial protocols was shown as feasible across countries of the European Union. At the same time, coordination between Europe, Japan and the United States led to a joint regulatory-industry initiative on international harmonization named after 1990 as the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) Currently, most clinical trial programs follow ICH guidelines, aimed at "ensuring that good quality, safe and effective medicines are developed and registered in the most efficient and cost-effective manner. These activities are pursued in the interest of the consumer and public health, to prevent unnecessary duplication of clinical trials in humans and to minimize the use of animal testing without compromising the regulatory obligations of safety and effectiveness."
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.
The standard approach is reversed-phase high-performance liquid chromatography, with purity reported as the relative area of the main peak. Ultraviolet detection near 214 nanometers is typical for peptides. Mass spectrometry is added to confirm identity rather than to quantify purity.