五肽 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
At the cellular level, ipamorelin binds the growth hormone secretagogue receptor, also called the ghrelin receptor. Activation of this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to release of growth hormone into circulation. Because release follows a pulsatile pattern, studies often report peak concentration and total area under the curve rather than a single time point. Selectivity for this receptor is the property most frequently discussed in comparative work.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility class | Soluble in water and aqueous buffers | Solubility can depend on pH and salt form |
| Typical storage temperature | −20 °C or lower, desiccated | Protect from light and moisture |
| Typical analytical method | RP-HPLC with UV detection; LC-MS | Identity and purity assessment |
| Common salt form | Acetate salt | Frequently used in research supply |
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。
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.
==== Spontaneous intracranial hypotension ==== Spontaneous intracranial hypotension (SIH) refers to lower than normal CSF volume due to a leak of CSF at the level of the spine. Spontaneous intracranial hypotension (SIH) is an important cause of longstanding headaches. Other symptoms can include nausea, blurred vision, coma, and dementia. SIH is typically secondary to a spontaneous spinal CSF leak. Cranial CSF leaks do not cause SIH. While this symptom can be referred to as intracranial hypotension, the intracranial pressure may be normal, with the underlying issue instead being low CSF volume, in this case a sCSFL may be referred to as CSF hypovolemia.
== See also == Cosmetic pharmacology Ergogenic use of anabolic steroids List of doping cases in sport List of drugs used by militaries Natural bodybuilding Neuroenhancement Steroid use in American football
== Membership of scientific organizations == Hungarian Chemical Society Hungarian Biochemical Society Committee of Peptide Research of Hungarian Academy of Sciences Society of Hungarian Oncologists Member of the Council of Res.Institutes of Hungarian Academy of Sciences European Peptide Society American Peptide Society International Society of Oncodevelopmental Biology and Medicine European Association for Cancer Research Executive Committee of EC European Biotechnology Consortium President of the Curatorium of the Szekerke Mária Cancer Research Foundation Vice President of the European Biotechnology Thematic Network Association (2009–2011) Member of the Healthcare Council of EuropaBio
== Eye disease == Mutation in rhodopsin kinase can result in diseases such as Oguchi disease and retinal degeneration. Oguchi disease is a form of congenital stationary night blindness (CSNB). Congenital stationary night blindness is caused by the inability to send a signal from outer retina to the inner retina by signaling molecules. Oguchi disease is a genetic disorder so an individual can be inherited from his or her parents. Genes that are responsible for Oguchi disease are SAG (which encodes arrestin) and GRK1 genes. Rhodopsin kinase is encoded from the GRK1 gene, so a mutation in GRK1 can result in Oguchi disease. Retinal degeneration is a form of the retinal disease caused by the death of photoreceptor cells that present in the back of the eye, retina. Rhodopsin kinase directly participates in the rhodopsin to activate the visual phototransduction. Studies have shown that lack of rhodopsin kinase will result in photoreceptor cell death. When photoreceptors cells die, they will be detached from the retina and result in retinal degeneration.
Sources: en.wikipedia.org
Gloves made of natural rubber (latex) do not properly withstand chemical attacks, a.o. by concentrated nitric acid (e.g., 6 M HNO3) commonly used to keep polonium in solution while minimizing its sorption onto glass. They do not provide sufficient protection against the contamination from polonium (diffusion of 210Po solution through the intact latex membrane, or worse, direct contact through tiny holes and cracks produced when the latex begins to suffer degradation by acids or UV from ambient light); additional surgical gloves are necessary (inside the glovebox to protect the main gloves when handling strong acids and bases, and also from outside to protect the operator hands against 210Po contamination from diffusion, or direct contact through glove defects). Chemically more resistant, and also denser, neoprene and butyl gloves shield alpha particles emitted by polonium better than natural rubber. The use of natural rubber gloves is not recommended for handling 210Po solutions.
Biotechnology in the general sense has been an important part of biology since the late 19th century. With the industrialization of brewing and agriculture, chemists and biologists became aware of the great potential of human-controlled biological processes. In particular, fermentation proved a great boon to chemical industries. By the early 1970s, a wide range of biotechnologies were being developed, from drugs like penicillin and steroids to foods like Chlorella and single-cell protein to gasohol—as well as a wide range of hybrid high-yield crops and agricultural technologies, the basis for the Green Revolution.
PfSSM (2008), CBM and CCF (2008) for Plasmodium proteins, which have a different amino acid evolutionary bias due to the low GC content of the genome. Matrices for transmembrane proteins. JTT transmembrane (1994) is the first of the class. Later work include: For alpha-helical transmembrane proteins, PHAT (2000) and SLIM (2001). For beta-barrel transmembrane proteins, bbTM (2008). Matrices for a specific protein family, including GPCRtm (2015) for the transmembrane (mostly helical) regions of GPCRs. Matrices for proteins with a specific role, including Hubsm (2017) for "hub proteins" in protein‐protein interaction networks. Matrices for intrinsically disordered proteins, including DUNMat (2002), MidicMat (2009), Disorder (2010), and EDSSMat (2019).
=== Service with other air forces === After World War II, the P-51 Mustang served in the air arms of more than 25 nations. During the war, a Mustang cost about $51,000, while many hundreds were sold postwar for the nominal price of one dollar to signatories of the Inter-American Treaty of Reciprocal Assistance, ratified in Rio de Janeiro in 1947. These countries used the P-51 Mustang:
As of January 2006, about two thirds of worldwide structural genomics (SG) output was made by PSI centers. Of these PSI contributions over 20% represented new Pfam families, compared to the non-SG average of 5%. Pfam families represent structurally distinct groups of proteins as predicted from sequenced genomes. Not targeting homologs of known structure was accomplished by using sequence comparison tools like BLAST and PSI-BLAST. Like the difference in novelty as determined by discovery of new Pfam families, the PSI also discovered more SCOP folds and superfamilies than non-SG efforts. In 2006, 16% of structures solved by the PSI represented new SCOP folds and superfamilies, while the non-SG average was 4%. Solving such novel structures reflects increased coverage of protein fold space, one of the PSI's main goals. Determining the structure a novel protein allows homology modeling to more accurately predict the fold of other proteins in the same structural family. While most of the structures solved by the four large-scale PSI centers lack functional annotation, many of the remaining PSI centers determine structures for proteins with known biological function. The TB Structural Genomics Consortium, for example, focused exclusively on functionally characterized proteins. During its term in PSI-1, it deposited structures for over 70 unique proteins from Mycobacterium tuberculosis, which represented more than 35% of total unique M. tuberculosis structures solved through 2007.
Sources: en.wikipedia.org
Purity is commonly estimated by reversed-phase high-performance liquid chromatography with ultraviolet detection. Mass spectrometry is used to confirm identity and to detect sequence-related impurities. Reported percentages depend on the method and the impurity threshold used.
Lyophilized powder is usually kept frozen, desiccated, and protected from light. Reconstituted solutions are often divided into aliquots and stored at very low temperature to limit freeze-thaw cycles. Specific conditions should follow the supplier's certificate of analysis and the assay requirements.
Much of the evidence comes from animal models and cell-based assays rather than large human trials. Small sample sizes, short follow-up, and differences in dosing or route make comparisons difficult. Questions about long-term effects and human relevance remain open.
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.