If you have been reading about intranasal delivery and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-04-17. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
=== Mapping from A1c to estimated average glucose === The approximate mapping between HbA1c values given in DCCT percentage (%) and eAG (estimated average glucose) measurements is given by the following equation:
=== Chemi-ionization === Chemi-ionization is the formation of an ion through the reaction of a gas phase atom or molecule with an atom or molecule in an excited state. Chemi-ionization can be represented by
=== Interaction with ethanol === Concurrent use with ethanol is contraindicated because fomepizole is known to prolong the half-life of ethanol via inhibiting its metabolism to acetaldehyde by alcohol dehydrogenase.
Sources: en.wikipedia.org
=== Controversy === According to the American Headache Society, "Patients frequently state that they have difficulty accessing triptans prescribed to them." In the US, triptans cost from $12 to $120 each, and more than 80% of US health insurance plans place a limit on the number of pills available to a patient per month, which has been called "arbitrary and unfair."
== Structure == Apart from their subcellular location and the abundance of acidic residues (Asp and Glu), these proteins do not share many structural similarities. Only one short region, located in the C-terminal section, is conserved in all these proteins. Chromogranins and secretogranins together share a C-terminal motif, whereas chromogranins A and B share a region of high similarity in their N-terminal section; this region includes two cysteine residues involved in a disulfide bond. There are considerable differences in the amino acid composition between different animals. Commercial assays for measuring human CGA can usually not be used for measuring CGA in samples from other species. Some specific parts of the molecule have a higher degree of amino acid homology and methods where the antibodies are directed against specific epitopes can be used to measure samples from different animals. Region-specific assays measuring defined parts of CGA, CGB and SG2 can be used for measurements in samples from cats and dogs.
==== Education ==== The educational field also was a major way for adopting Western-style music. The educational reforms were led by Isawa Shūji (1851–1917) and Luther Whiting Mason (1828–1896). In 1880, the Music Research Institute in Tokyo (Ongaku Torishirabe Gakari), headed by Izawa Shuji, was founded. The Institute had three main tasks: 1) to introduce compulsory music teaching in schools, to introduce Western-style songs; 2) to train music teachers for the further development of professional musical activities; 3) to create music score collections for children, in which Japanese and Western style music elements could be combined. Thus, the first music scores "The First Collection for Primary School" was published in 1881. The newly educated music teachers organized lessons in singing, music theory, playing musical instruments (koto, kokyū, piano, organ and violin). In 1887, the Music Research Institute was reformed into Tokyo Academy of Music, which gave the Institution a new status and contributed to its further development. Western music was regarded as an essential contributory factor for modernization. The new curriculum was improved, and the number and quality of the musical events increased. Tokyo Academy of Music became the first Western-style music educational establishment in Japan. This was the nascence of schools teaching composition in the Western style in Japan, the genesis of an opera tradition in Japan, and laid the foundations for the Japanese formal tradition of familiarization with Western music.
Sources: en.wikipedia.org
== Honours and awards == 1988 Alexander von Humboldt fellowship of Germany: Research with Jürgen Martens at the University of Oldenburg and Hans Brückner University of Giessen. 1992 European Economic Community Fellowship: Research with Peter Shewry University of Bristol 1993 Fellow of the Royal Society of Chemistry 2001 Fellow of the National Academy of Sciences India
Alexander Stewart; Joseph Chi-Fung Ng; Gillian Wallis; Vasiliki Tsioligka; Franca Fraternali; Deborah K Dunn-Walters (18 March 2021). "Single-Cell Transcriptomic Analyses Define Distinct Peripheral B Cell Subsets and Discrete Development Pathways". Frontiers in Immunology. 12 602539. doi:10.3389/FIMMU.2021.602539. ISSN 1664-3224. PMC 8012727. PMID 33815362. Alexander Stewart; Emma Sinclair; Joseph Chi-Fung Ng; et al. (3 May 2022). "Pandemic, Epidemic, Endemic: B Cell Repertoire Analysis Reveals Unique Anti-Viral Responses to SARS-CoV-2, Ebola and Respiratory Syncytial Virus". Frontiers in Immunology. 13 807104. doi:10.3389/FIMMU.2022.807104. ISSN 1664-3224. PMC 9111746. PMID 35592326. Kate L Gibson; Yu-Chang Wu; Yvonne Barnett; et al. (5 November 2008). "B-cell diversity decreases in old age and is correlated with poor health status". Aging Cell. 8 (1): 18–25. doi:10.1111/J.1474-9726.2008.00443.X. ISSN 1474-9718. PMC 2667647. PMID 18986373. Yu-Chang Wu; David Kipling; Hui Sun Leong; Victoria Martin; Alexander A Ademokun; Deborah K Dunn-Walters (10 May 2010). "High-throughput immunoglobulin repertoire analysis distinguishes between human IgM memory and switched memory B-cell populations". Blood. 116 (7): 1070–1078. doi:10.1182/BLOOD-2010-03-275859. ISSN 0006-4971. PMC 2938129. PMID 20457872. D. K. Dunn-Walters; P. G. Isaacson; J. Spencer (1 August 1995). "Analysis of mutations in immunoglobulin heavy chain variable region genes of microdissected marginal zone (MGZ) B cells suggests that the MGZ of human spleen is a reservoir of memory B cells" (PDF).
=== Monitoring === Enoxaparin has predictable absorption, bioavailability, and distribution therefore monitoring is not typically done. However, there are instances where monitoring may be beneficial for special populations, for example individuals with kidney insufficiency or those that are obese. In this case, anti-Xa units can be measured and dosing adjusted accordingly.
Uranium is pyrophoric when finely divided. It will corrode under the influence of air and water producing insoluble uranium(IV) and soluble uranium(VI) salts. Soluble uranium salts are toxic. Uranium slowly accumulates in several organs, such as the liver, spleen, and kidneys. The World Health Organization has established a daily "tolerated intake" of soluble uranium salts for the general public of 0.5 micrograms per kilogram (3.5×10−6 gr/lb) body weight, or 35 micrograms (0.00054 gr) for a 70 kilograms (150 lb) adult. Epidemiological studies and toxicological tests on laboratory animals point to it as being immunotoxic, teratogenic, neurotoxic, with carcinogenic and leukemogenic potential. A 2005 report by epidemiologists concluded: "the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU." Early studies of depleted uranium aerosol exposure assumed that uranium combustion product particles would quickly settle out of the air and thus could not affect populations more than a few kilometers from target areas, and that such particles, if inhaled, would remain undissolved in the lung for a great length of time and thus could be detected in urine. Violently burning uranium droplets produce a gaseous vapor comprising about half of the uranium in their original mass. Uranyl ion contamination in uranium oxides has been detected in the residue of DU munitions fires. Approximately 90 micrograms (0.0014 gr) of natural uranium, on average, exist in the human body as a result of normal intake of water, food and air.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.