A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-08-13. Anything still debated is marked as such rather than presented as settled.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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.
Ibopamine is a sympathomimetic drug, designed as a prodrug of epinine (deoxyepinephrine or N-methyldopamine), used in ophthalmology. It induces mydriasis. It also has been investigated for use in the treatment of congestive heart failure. It acts on D1 and α-adrenergic receptors as an agonist. Ibopamine was first prepared by Casagrande and co-workers. Instilled at 2% concentration, ibopamine exhibits several functions at ocular level such as pre- and post-operative mydriatic activity, D1 dopaminergic activity, etc.
Niels Lund Chrestensen (9 August 1940 – 16 August 2025) was a German businessman and plant breeder. He was a recipient of the Order of Merit of the Federal Republic of Germany (1999). Chrestensen died on 16 August 2025, in Erfurt, Thuringia, at the age of 85.
Based on modeled and observed accumulated cyclone energy (ACE), El Niño years usually result in less active hurricane seasons in the Atlantic Ocean, but instead favor a shift to tropical cyclone activity in the Pacific Ocean, compared to La Niña years favoring above average hurricane development in the Atlantic and less so in the Pacific basin. Over the Atlantic Ocean, vertical wind shear is increased, which inhibits tropical cyclone genesis and intensification, by causing the westerly winds to be stronger. The atmosphere over the Atlantic Ocean can also be drier and more stable during El Niño events, which can inhibit tropical cyclone genesis and intensification. Within the Eastern Pacific basin: El Niño events contribute to decreased easterly vertical wind shear and favor above-normal hurricane activity. However, the impacts of the ENSO state in this region can vary and are strongly influenced by background climate patterns. The Western Pacific basin experiences a change in the location of where tropical cyclones form during El Niño events, with tropical cyclone formation shifting eastward, without a major change in how many develop each year. As a result of this change, Micronesia is more likely, and China less likely, to be affected by tropical cyclones. A change in the location of where tropical cyclones form also occurs within the Southern Pacific Ocean between 135°E and 120°W, with tropical cyclones more likely to occur within the Southern Pacific basin than the Australian region.
=== The 26Al – 26Mg chronometer === Another example of short-lived extinct radionuclide dating is the 26Al – 26Mg chronometer, which can be used to estimate the relative ages of chondrules. 26Al decays to 26Mg with a half-life of 720 000 years. The dating is simply a question of finding the deviation from the natural abundance of 26Mg (the product of 26Al decay) in comparison with the ratio of the stable isotopes 27Al/24Mg. The excess of 26Mg (often designated 26Mg*) is found by comparing the 26Mg/27Mg ratio to that of other Solar System materials. The 26Al – 26Mg chronometer gives an estimate of the time period for formation of primitive meteorites of only a few million years (1.4 million years for Chondrule formation).
Sources: en.wikipedia.org
=== Cardiovascular disease === Cardiovascular disease can present itself in many different forms, from cardiomyopathy to peripheral arterial disease, and heart disease remains a key threat to human health. While there are means of therapy to both prevent and cure cardiovascular diseases, many drugs are unavailable for clinical use due to severe side effects in addition to high toxicity levels. However, in the past decade, sv-LAAOs have shown promise in affecting platelet aggregation. It has been proposed that hydrogen peroxide is considered to play a significant role regarding the enzymes ability to both cause and prevent this platelet aggregation. With this knowledge, it appears that sv-LAAOs could be evaluated as a potential cardiovascular disease therapeutic because of their biological potency.
==== Plasma levels ==== Plasma potassium is normally kept at 3.5 to 5.5 millimoles (mmol) [or milliequivalents (mEq)] per liter by multiple mechanisms. Even narrower ranges are required to reduce mortality for patients with acute myocardial infarction. An average meal of 40–50 mmol presents the body with more potassium than is present in all plasma (20–25 mmol). Renal and extrarenal mechanisms external homeostasis mechanisms limit the rise in plasma potassium to less than 10%. Hypokalemia, a deficiency of potassium in the plasma, can be fatal if severe. Common causes are increased gastrointestinal loss (vomiting, diarrhea), and increased renal loss (diuresis). Deficiency symptoms include muscle weakness, paralytic ileus, ECG abnormalities, decreased reflex response; and in severe cases, respiratory paralysis, alkalosis, and cardiac arrhythmia.
Halocins are bacteriocins produced by halophilic Archaea and a type of archaeocin. Since their discovery in 1982, halocins have been demonstrated to be diverse in a similar ways as the other bacteriocins. Some are large proteins, some small polypeptides (microhalocins). This diversity is surprising for a number of reasons, including the original presumptions that Archaea, particularly extremophiles, live at relatively low densities under conditions that may not require antagonistic behavior. The genetics, mechanism of production and mechanism of action of the halocins have been studied, but not exhaustively. The ecology of the halocins has been investigated as well. One interesting observation is that the halocins are active across the major divisions of archaea, thus violating the dogma that they should be most effective against the most closely related strains. Halocins are particularly interesting because of the way the pore-forming bacteriocins have been used to probe cell membrane structure and the production and maintenance of energetic ion gradients across the membrane. The halophiles live at such extreme ion concentrations that they represent a set of unusual solutions and adaptations with regard to their energetic gradients. The ability to use native halocins to study these gradients provides a motivation for their characterization. They may have a role in human medicine. They are also found in many of the type species that are used to learn about halophiles in general.
This gives the antivenin its polyvalent property. This also enhances the potency of the antivenin. Some venoms cannot induce the immune system enough on its own or the combination of two or more venoms result in a better responding antivenin.
== U == UbiD protein domain - ubiquitin—calmodulin ligase - UDP-3-O-N-acetylglucosamine deacetylase - UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine transaminase - undecaprenyl-phosphate 4-deoxy-4-formamido-L-arabinose transferase - untranslated RNA - upstream - upstream activator sequence - upstream DNA - upstream (transduction) - uracil - uracil/thymine dehydrogenase - ureidoglycolate hydrolase -
Sources: en.wikipedia.org
Typically found in young children and is the most common cause at this age. Generally occurs after a viral infection of adenovirus (types 3, 7, and 21), measles (rubeola), mycoplasma, CMV, influenza, and parainfluenza. Swyer-James syndrome is a rare complication of bronchiolitis obliterans caused by measles or adenovirus. Post-infectious bronchiolitis obliterans is most common in the southern hemisphere particularly in countries such as Brazil, Argentina, Australia, Chile and New Zealand. There was a large prevalence of the disease in these areas during the 1990s and early 2000s. In one hospital in Buenos Aires, the Ricardo Gutiérrez Children's hospital, the disease accounted for 14% of their inpatient respiratory population from 1993 to 2002. As such, much of the information about post-infectious bronchiolitis obliterans has come from research out of South America. The most significant risk factors for the disease are infection with adenovirus and the need for ventilator support. In contrast with another cause of bronchiolitis obliterans in children, Steven's Johnson's syndrome, post-infectious bronchiolitis obliterans tends to be a chronic but non-progressive disease. The disease can have varying impact on children and their quality of life, which has been studied by lung function tests, as well as their exercise tolerance. Children with lower lung function based on their pulmonary function testing, have lower exercise tolerance, which compounds the impact of the disease on cardiovascular function as they are not able to maintain age appropriate aerobic fitness.
=== Pain modulation === Like other dynorphin peptides, big dynorphin can produce analgesic effects through κ-opioid receptor (KOR) activation at spinal nociceptive sites. However, at supraspinal levels through non-opioid mechanisms involving NMDA receptor modulation and ASIC1a activation, big dynorphin can produce pro-nociceptive effects, enhancing pain sensitivity in both acute and chronic pain states.
It has one boxed warning by the US FDA, namely severe hepatotoxicity including fatalities. The most common side effects of pazopanib are nausea, vomiting, diarrhoea (occurs in about half of patients), changes in hair colour, hypertension (which usually occurs during the first few weeks of treatment), appetite loss, hyperglycaemia, hypoglycaemia, electrolyte abnormalities (including hypocalcaemia, hypomagnesemia, hypophosphatemia), laboratory anomalies (including increased AST, ALT and protein in the urine), oedema, hair loss or discolouration, taste changes, abdominal pain, rash, fatigue and bone marrow suppression (including leucopenia, neutropenia, thrombocytopenia and lymphopenia). It has been associated with a low, but real risk of potentially fatal liver damage.
January 7 Killing of Renée Good: A 37-year-old woman is shot and killed by an Immigration and Customs Enforcement officer in Minneapolis, Minnesota. Trump announces that the United States will withdraw from 66 international organizations. The Department of State suspends all ongoing assistance programs to Somalia. Two people are killed and six others are injured in a mass shooting during a funeral at a LDS Church meetinghouse in Salt Lake City, Utah. January 10 – 2025–26 measles outbreak: North Carolina experiences a surge in measles over the past week, with cases rising to 310 in the state alone. Nearly 2,500 are reported nationally. January 11 Federal prosecutors open a criminal investigation into Federal Reserve chair Jerome Powell over the testimony he gave to a Senate committee about renovations to Federal Reserve buildings. Low-cost airline Allegiant Air purchases Sun Country Airlines for $1.5 billion. Three inmates are killed, thirteen others are hospitalized, and a guard is injured when violence breaks out at the Washington State Prison in Davisboro, Georgia. January 12 Mattel launches its first autistic Barbie. January 13 The Trump administration designates the Muslim Brotherhood in Egypt, the Islamic Group in Lebanon, and the Islamic Action Front in Jordan as foreign terrorist organizations for their support of Hamas. Meta announces the closure of the studios Armature Studio, Sanzaru Games, and Twisted Pixel. In addition, they announced more than 1,000 workers would be laid off in their Reality Labs business.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.