Everything below concerns ACTH fragment. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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。
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
Causes: (a) Microvesicular: Aspirin (Reye's syndrome), ketoprofen, tetracycline (especially if expired) (b) Macrovesicular: Acetaminophen, methotrexate (c) Phospholipidosis: Amiodarone, total parenteral nutrition (d) Antiviral: nucleoside analogues (e) Corticosteroid (f) Hormonal: Tamoxifen
Audience tastes were fairly eclectic during the 20th century, but several trends did emerge. During the silent era, films with war themes were popular with audiences, with The Birth of a Nation (American Civil War), The Four Horsemen of the Apocalypse, The Big Parade and Wings (all World War I) becoming the most successful films in their respective years of release, with the trend coming to an end with All Quiet on the Western Front in 1930. With the advent of sound in 1927, the musical—the genre best placed to showcase the new technology—took over as the most popular type of film with audiences, with 1928 and 1929 both being topped by musical films. The genre continued to perform strongly in the 1930s, but the outbreak of World War II saw war-themed films dominate again during this period, starting with Gone with the Wind (American Civil War) in 1939, and finishing with The Best Years of Our Lives (World War II) in 1946. Samson and Delilah (1949) saw the beginning of a trend of increasingly expensive historical dramas set during Ancient Rome/biblical times throughout the 1950s as cinema competed with television for audiences, with Quo Vadis, The Robe, The Ten Commandments, Ben-Hur and Spartacus all becoming the highest-grossing film of the year during initial release, before the genre started to wane after several high-profile failures. The success of White Christmas and South Pacific in the 1950s foreshadowed the comeback of the musical in the 1960s with West Side Story, Mary Poppins, My Fair Lady, The Sound of Music and Funny Girl all among the top films of the decade.
== T == T cell - T-cell antigen receptors - tachykinin - tachykinin receptor - talin protein - tandem repeat sequence - taste bud - TATA box - tax gene product - taxonomy - telophase - tertiary structure - tetrodotoxin - thermochemistry - thermometer - thiamin - thioredoxin - threonine - thrombin - thrombin receptor - thrombomodulin - thromboxane receptor - thylakoid - thyroid hormone receptor - thyrotropin - thyrotropin receptor - thyrotropin-releasing hormone receptor - thyroxine - timeline of biology and organic chemistry - titration - tobacco mosaic virus - topoisomerase - toxin - trans-activator - transcription factor - transcription factor AP-1 - transducin - transformation - transforming growth factor - transforming growth factor alpha - transforming growth factor beta - transforming growth factor beta receptor - transient receptor potential - translation (biology) - transmembrane ATPase - transmembrane helix - transmembrane protein - transmembrane receptor - transport protein - transport vesicle - triiodothyronine - trinucleotide repeat - triose - tropomyosin - troponin - tryptophan - tubulin - tumor necrosis factors - tumor necrosis factor receptor - tyrosine - tyrosine 3-monooxygenase
=== Analogs === Some analog substances have been created which mimic caffeine's properties with either function or structure or both. Of the latter group are the xanthines DMPX and 8-chlorotheophylline, which is an ingredient in dramamine. Members of a class of nitrogen substituted xanthines are often proposed as potential alternatives to caffeine. Many other xanthine analogues constituting the adenosine receptor antagonist class have also been elucidated. Some other caffeine analogs:
=== Cardiac === SSRIs do not appear to affect the risk of coronary heart disease (CHD) in those without a previous diagnosis of CHD. A large cohort study suggested no substantial increase in the risk of cardiac malformations attributable to SSRI usage during the first trimester of pregnancy. A number of large studies of people without known pre-existing heart disease have reported no EKG changes related to SSRI use. The recommended maximum daily dose of citalopram and escitalopram was reduced due to concerns with QT prolongation. In overdose, fluoxetine has been reported to cause sinus tachycardia, myocardial infarction, junctional rhythms, and trigeminy. Some authors have suggested electrocardiographic monitoring in patients with severe pre-existing cardiovascular disease who are taking SSRIs. In a 2023 study, a possible connection between SSRI usage and the onset of mitral valve regurgitation was identified, indicating that SSRIs could hasten the progression of degenerative mitral valve regurgitation (DMR), especially in individuals carrying 5-HTTLPR genotype. The study's authors suggest that genotyping should be performed on people with DMR to evaluate serotonin transporter (SERT) activity. They also urge practitioners to exercise caution when prescribing SSRIs to individuals with a familial history of DMR.
Sources: en.wikipedia.org
The UK government rejects a call from Plaid Cymru to devolve responsibility for the Crown Estate in Wales to the Welsh Government, saying it would make no sense to do so. Northern Ireland's Deputy First Minister, Emma Little-Pengelly confirms she will travel to Washington for St Patrick's Day celebrations at the White House. 25 February Keir Starmer announces cuts to international aid to fund an increase of defence spending to 2.5% of GDP by 2027. In her first major speech on foreign policy, Kemi Badenoch said the UK should leave the European Convention on Human Rights (ECHR). Reform UK gains its first representative on Cornwall Council following the defection of Conservative councillor Kevin Towill. Business Secretary Jonathan Reynolds apologises for saying he worked as a solicitor before he became an MP. The first round of cross-party talks on social care reform in England is postponed. 27 February – Starmer meets with US President Donald Trump at the White House for talks on Ukraine and defence. King Charles III invites Trump to the UK for a second state visit. Labour MP Mike Amesbury's prison sentence is suspended following an appeal. 28 February – International Development Minister Anneliese Dodds resigns over the prime minister's cuts to the foreign aid budget, saying the UK's reputation will be deeply harmed. Former Conservative Attorney General Dominic Grieve is appointed by the UK government to lead a review into creating a new definition of Islamophobia.
Each year, approximately one million deaths are due to complications of cirrhosis, making cirrhosis the 11th most common cause of death globally. Cirrhosis and chronic liver disease were the tenth leading cause of death for men and the twelfth for women in the United States in 2001, killing about 27,000 people each year. The cause of cirrhosis can vary; alcohol and non-alcoholic fatty liver disease are main causes in western and industrialized countries, whereas viral hepatitis is the predominant cause in low and middle-income countries. Cirrhosis is more common in men than in women. The cost of cirrhosis in terms of human suffering, hospital costs, and lost productivity is high. Globally, age-standardized disability-adjusted life year (DALY) rates have decreased from 1990 to 2017, with the values going from 656.4 years per 100,000 people to 510.7 years per 100,000 people. In males DALY rates have decreased from 903.1 years per 100,000 population in 1990, to 719.3 years per 100,000 population in 2017; in females the DALY rates have decreased from 415.5 years per 100,000 population in 1990, to 307.6 years per 100,000 population in 2017. However, globally the total number of DALYs has increased by 10.9 million from 1990 to 2017, reaching the value of 41.4 million DALYs.
== Biosynthesis and occurrence == It is produced in eukaryotic organisms from succinate in complex 2 of the electron transport chain via the enzyme succinate dehydrogenase. Fumaric acid is found in fumitory (Fumaria officinalis), bolete mushrooms (specifically Boletus fomentarius var. pseudo-igniarius), lichen, and Iceland moss. Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP) from food. It is formed by the oxidation of succinate by the enzyme succinate dehydrogenase. Fumarate is then converted by the enzyme fumarase to malate. Human skin naturally produces fumaric acid when exposed to sunlight. Fumarate is also a product of the urea cycle. Click on genes, proteins and metabolites below to link to respective articles.
Bacterial metabolic traits play important roles in maintaining ecological processes and supporting human activities. For example, diazotrophs have the ability to fix nitrogen gas using the enzyme nitrogenase. This trait, which can be found in bacteria of most metabolic types listed above, leads to the ecologically important processes of denitrification, sulfate reduction, and acetogenesis, respectively. Bacterial metabolic processes are important drivers in biological responses to pollution; for example, sulfate-reducing bacteria are largely responsible for the production of the highly toxic forms of mercury (methyl- and dimethylmercury) in the environment. Nonrespiratory anaerobes use fermentation to generate energy and reducing power, secreting metabolic by-products (such as ethanol in brewing) as waste. Facultative anaerobes can switch between fermentation and different terminal electron acceptors depending on the environmental conditions in which they find themselves.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.