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This page was last updated on 2026-02-21 and is reviewed periodically as new material appears.
Compared with other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.
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, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic pentapeptide | Growth hormone secretagogue family |
| Molecular mass | Approximately 711.9 Da | Free base, calculated value |
| Receptor target | GHS-R1a, the ghrelin receptor | Agonist activity reported |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | C-terminal amide |
| Reported selectivity | Little change in ACTH, cortisol, prolactin | Based mainly on animal data |
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.
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。
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.
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.
Storage recommendations for ipamorelin usually focus on temperature, moisture, and light. Lyophilized powder is typically held at or below minus twenty degrees Celsius in a desiccated container protected from light. Reconstituted solutions are often aliquoted and stored at minus eighty degrees Celsius to reduce repeated freeze-thaw cycles, which can promote aggregation or degradation. The optimal buffer and pH depend on the specific assay, and no single condition applies to every experimental context. Peptide stability should be assessed with time-point measurements rather than assumed from general handling rules.
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.
The US Federal Aviation Administration issued a notice to airmen on 3 January 2026 prohibiting US aircraft from operating within Venezuelan airspace, citing "ongoing military activity". The US Embassy in Caracas issued a shelter-in-place order from its relocated operations in Colombia. The southern area of Caracas reportedly lost power. Republican Senator Mike Lee said that Secretary of State Marco Rubio "anticipates no further action in Venezuela now that Maduro is in US custody," and that Maduro was expected to go on trial in the US. In the hours after the US attack, Rubio placed a call with Delcy and Jorge Rodríguez, as well as Mauricio Claver-Carone, who was involved in the plan to abduct Maduro and would go on to serve as an unofficial viceroy for the Trump administration in Venezuela. In a television interview with ABC News, Rubio thanked news organizations who had received leaks about the operation before it took place for not reporting on it. According to Semafor, The New York Times and The Washington Post had received information about the attack but did not report on it in order to not endanger the lives of US personnel involved in the operation. The acknowledgment of the media withholding information about the operation came after defense secretary Pete Hegseth imposed strict restrictions on Pentagon reporters due to a mistrust of journalists' abilities to withhold militarily sensitive information from the public.
CH2=CH(NH2)CO2H + H2O → CH3−C(O)CO2H + NH3 N-Acylated derivatives of dehydroalanine, such as are found peptides and related compounds, are stable. One such example is methyl 2-acetamidoacrylate. As a residue in a peptide, dehydroalanine is generated by a post translational modification. The required precursors are serine or cysteine residues, which undergo enzyme-mediated loss of water and hydrogen sulfide, respectively. Most amino acid residues are unreactive toward nucleophiles, but those containing dehydroalanine or some other dehydroamino acids are exceptions. These residues are electrophilic due to the α,β-unsaturated carbonyl, and can, for example, alkylate other amino acids. This activity has made DHA useful synthetically to prepare lanthionine.
== Further reading == Breslau-Siderius, E. J.; et al. (1998). "Brack syndrome: a rare combination of bone fragility and multiple congenital joint contractures". Journal of Pediatric Orthopaedics B. 7 (1): 35–38. doi:10.1097/01202412-199801000-00006.
At antidepressant doses of above 75 mg, doxepin is more stimulating with antiadrenergic, antiserotonergic, and anticholinergic effects, and these activities contribute to its side effects. Doxepin is a mixture of (E) and (Z) stereoisomers with an approximate ratio of 85:15. When doxepin was developed, no effort was made to separate or balance the mixture following its synthesis, resulting in the asymmetric ratio. (Z)-Doxepin is more active as an inhibitor of serotonin and norepinephrine reuptake than (E)-doxepin. The selectivity of doxepin for inhibition of norepinephrine reuptake over that of serotonin is likely due to the 85% presence of (E)-doxepin in the mixture. Most other tertiary amine TCAs like amitriptyline and imipramine do not exhibit E-Z isomerism or such mixture asymmetry and are comparatively more balanced inhibitors of serotonin and norepinephrine reuptake.
== History == Pfizer brought the drug to market as Vfend. A generic version of the tablet form of voriconazole was introduced in the US in 2011 after Pfizer and Mylan settled litigation under the Hatch-Waxman Act; a generic version of the injectable form was introduced in 2012. In Europe, patent protection expired in 2011, and pediatric administrative exclusivity expired in 2016.
Sources: en.wikipedia.org
=== Selectively neutral similarities === Similarities which have no adaptive relevance cannot be explained by convergent evolution, and therefore they provide compelling support for universal common descent. Such evidence has come from two areas: amino acid sequences and DNA sequences. Proteins with the same three-dimensional structure need not have identical amino acid sequences; any irrelevant similarity between the sequences is evidence for common descent. In certain cases, there are several codons (DNA triplets) that code redundantly for the same amino acid. Since many species use the same codon at the same place to specify an amino acid that can be represented by more than one codon, that is evidence for their sharing a recent common ancestor. Had the amino acid sequences come from different ancestors, they would have been coded for by any of the redundant codons, and since the correct amino acids would already have been in place, natural selection would not have driven any change in the codons, however much time was available. Genetic drift could change the codons, but it would be extremely unlikely to make all the redundant codons in a whole sequence match exactly across multiple lineages. Similarly, shared nucleotide sequences, especially where these are apparently neutral such as the positioning of introns and pseudogenes, provide strong evidence of common ancestry.
=== Military Union and People's Alliance === The dismissal of Kimon Georgiev was followed by the purge of other key figures of the Union by the end of 1920. Despite the government's measures, the Military Union was gradually restored with the active efforts of Nikola Rachev, Damyan Velchev and Kimon Georgiev - the structure of the organization in the army was reorganized, with fewer people involved in its activities, but under a tighter conspiracy. His political career started in 1921, where he was one of the founders of the organization People's Alliance and kept ties with the Military Union. He also participated in the negotiation ties between opposition parties to create the Constitutional Bloc in 1922.
The protein component of AGPs is rich in the amino acids Proline (P), Alanine (A), Serine (S) and Threonine (T), also known as 'PAST', and this amino acid bias is one of the features used to identify them. AGPs are intrinsically disordered proteins as they contain a high proportion of disordering amino acids such as Proline that disrupt the formation of stable folded structures. Characteristic of intrinsically disordered proteins, AGPs also contain repeat motifs and post-translational modifications. Proline residues in the protein backbone can be hydroxylated to Hydroxyproline (O) depending on the surrounding amino acids. The 'Hyp contiguity hypothesis' predicts that when O occurs in a non-contiguous manner, for example the sequence 'SOTO', such as occurs in AGPs, this acts as a signal for O-linked glycosylation of large branched type II arabinogalactan (AG) polysaccharides. Sequences that direct AG glycosylation (SO, TO, AO, VO) are called AGP glycomotifs. All AGP protein backbones contain a minimum of 3 clustered AGP glycomotifs and an N-terminal signal peptide that directs the protein into the endoplasmic reticulum (ER) where post-translational modifications begin. Prolyl hydroxylation of P to O is fulfilled by prolyl 4-hydroxylases (P4Hs) belonging to the 2-oxoglutarate dependant dioxygenase family. P4H has been identified in both the ER and Golgi apparatus. The addition of the glycosylphosphatidylinositol (GPI)-anchor occurs in most but not all AGPs.
The country had a 2019 Forest Landscape Integrity Index mean score of 5.95/10, ranking it 90th globally out of 172 countries. Some 3,700 plant species have been identified in the country, from which to date 23 have been declared natural monuments, 74 extinct, 39 endangered, 171 vulnerable, and 1,253 rare. The fauna of Romania consists of 33,792 species of animals, 33,085 invertebrate and 707 vertebrate, with almost 400 unique species of mammals, birds, reptiles, and amphibians, including about 50% of Europe's (excluding Russia) brown bears and 20% of its wolves. Romania is often seen by most as having the shape resembling one of a goldfish.
Sources: en.wikipedia.org
Ipamorelin is a synthetic pentapeptide that stimulates growth hormone release by activating the ghrelin receptor. It is handled as a research tool rather than as a licensed therapeutic product. Its short chain length makes it comparatively simple to synthesize and analyze.
Both bind the same receptor, but ghrelin is a 28-amino-acid hormone with roles in appetite and energy balance. Ipamorelin is a much smaller synthetic peptide selected for growth hormone release with limited effect on appetite signaling in animal models. The full overlap between their effects is not completely mapped.
Most published data come from animal studies and a small number of human trials. Findings on growth hormone release are reasonably consistent, while long-term effects and direct comparisons with other secretagogues remain incompletely studied. Open questions include duration of action across different populations.
Typical guidance is -20 °C in a sealed container with desiccant and protection from light. The powder tolerates handling better than a solution, but repeated warming and cooling is still avoided.