This is a working overview of Semax, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-31. 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.
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.
| 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。
== Medical uses == Terlipressin is indicated to improve kidney function in adults with hepatorenal syndrome with rapid reduction in kidney function. Indications for use include norepinephrine-resistant septic shock although, 2021 Surviving Sepsis Guidelines recommend against its use for adults with septic shock and hepatorenal syndrome. In addition, it is used to treat bleeding esophageal varices.
Au-catalyzed Cys alkylation Cysteine-containing peptides have been shown to undergo 1,2-addition to allenes in the presence of gold(I) and/or silver(I) salts, producing hydroxyl substituted vinyl thioethers. The reaction with peptides proceeds with high yields and is selective for cysteines over other nucleophilic residues. However, the reactivity towards proteins is much decreased, potentially due to the coordination of gold to the protein backbone.
or the total change of q from its generation or destruction inside the control volume. In a simple example, V could be a building, and q could be the number of living people in the building. The surface S would consist of the walls, doors, roof, and foundation of the building. Then the continuity equation states that the number of living people in the building (1) increases when living people enter the building (i.e., when there is an inward flux through the surface), (2) decreases when living people exit the building (i.e., when there is an outward flux through the surface), (3) increases when someone in the building gives birth to new life (i.e., when there is a positive time rate of change within the volume), and (4) decreases when someone in the building no longer lives (i.e., when there is a negative time rate of change within the volume). In conclusion, in this example there are four distinct ways that the net rate Σ may be altered.
Amyr was born to a Lebanese father and a Swedish mother. He moved to Paraty when he was two. Klink is a member of the Royal Geographical Society. He married Marina Bandeira in 1996 and has three daughters. In late 2021, Klink's daughter Tamara completed a solo sail across the Atlantic after accompanying her father on various expeditions.
Sources: en.wikipedia.org
=== Aldoses and ketoses === Monosaccharides which contain an aldehyde group are known as aldoses, and those with a ketone group are known as ketoses. The aldehyde can be oxidized via a redox reaction in which another compound is reduced. Thus, aldoses are reducing sugars. Sugars with ketone groups in their open chain form are capable of isomerizing via a series of tautomeric shifts to produce an aldehyde group in solution. Therefore, ketones like fructose are considered reducing sugars but it is the isomer containing an aldehyde group which is reducing since ketones cannot be oxidized without decomposition of the sugar backbone. This type of isomerization is catalyzed by the base present in solutions which test for the presence of reducing sugars.
Although Marxism–Leninism was created after Vladimir Lenin's death by Joseph Stalin in the Soviet Union, continuing to be the official state ideology after de-Stalinisation and of other communist states, the basis for elements of Marxism–Leninism predate this. The philosophy of Marxism–Leninism originated as the pro-active, political praxis of the Bolshevik faction of the Russian Social Democratic Labour Party in realising political change in Tsarist Russia. Lenin's leadership transformed the Bolsheviks into the party's political vanguard which was composed of professional revolutionaries who practised democratic centralism to elect leaders and officers as well as to determine policy through free discussion, then decisively realised through united action. The vanguardism of proactive, pragmatic commitment to achieving revolution was the Bolsheviks' advantage in out-manoeuvring the liberal and conservative political parties who advocated social democracy without a practical plan of action for the Russian society they wished to govern. Leninism allowed the Bolshevik party to assume command of the October Revolution in 1917.
Azurin's other domains may also exhibit strong anticancer activity by binding to cell surface receptor tyrosine kinases such as EphB2 receptors, which induce angiogenesis in cancer cells. This is another mechanism by which azurin has been proposed to exhibit its therapeutic effects.
In 1993, Hazleton, Besselaar, and SciCor were combined into Corning Pharmaceutical Services, then Corning Life Sciences. In 1995, Corning Pharmaceutical Services acquired National Packaging Systems, an Allentown, Pennsylvania-based clinical trial packaging company. In 1997, Corning completed the corporate spin-off of its laboratory testing business as Quest Diagnostics and its pharmaceutical services business as Covance. In the fourth quarter of 1998, the company acquired GDXI, which undertakes the capture and interpretation of electrocardiograms, and Berkeley Antibody Company, which provides contract services in custom antibody production, applied immunology, and custom animal testing to support the medical device industry and preclinical evaluations, for a total of $26 million in cash.
=== Protein-based materials and sustainability === A major strand of Mezzenga's work concerns the development of protein-derived and food-based materials as sustainable platforms for advanced technologies. His group has pioneered the use of amyloid fibrils as building blocks for functional nanocomposites, including biodegradable materials with sensing and shape-memory properties. In 2016, Mezzenga and collaborators reported amyloid–carbon hybrid membranes for universal water purification. The technology exploits supramolecular metal–ligand interactions between heavy-metal ions and protein amyloid fibrils, allowing simultaneous removal of a wide range of contaminants with high binding affinities. The membranes exhibit unusually high permeability, enabling operation with minimal energy input. This research led to patented technologies and the creation of an ETH Zurich spin-off company, BluAct Technologies, which has tested and deployed the approach in multiple countries. Mezzenga has also contributed to the development of conceptual frameworks for evaluating the sustainability of water purification technologies at large, emphasizing energy efficiency and material performance.
Sources: en.wikipedia.org
Intramuscular fat (also known as intramuscular triglycerides, intramuscular triacylglycerol, or intramyocellular triacylglycerol [IMTG]) is located inside skeletal muscle fibers. It is stored in lipid droplets that exist in close proximity to the mitochondria, where it serves as an energy store that can be used during exercise. In humans, excess accumulation of intramuscular fat has been associated with conditions such as insulin resistance and type 2 diabetes. The human immunodeficiency virus (HIV)-lipodystrophy syndrome is associated with over-accumulation of intramuscular fat, which may contribute to AIDS wasting syndrome.
== Toxicity == A few cases reported poisoning from commercially available products. The consumption of seeds represent a greater concern. Overconsumption of Ginkgo biloba seeds, especially by children, can result in loss of consciousness, convulsions, and death. Ginkgotoxin is structurally related to vitamin B6. It is suspected that ginkgotoxin interferes with the synthesis of the vitamin by decreasing the activity of pyridoxal kinase in mammals. This decrease leads to the decreased availability of glutamate decarboxylase. In turn, it causes an imbalance between excitation and inhibition of neurotransmitters, resulting in epileptic seizures. The toxicity of ginkgotoxin consequently can be relieved by taking vitamin B6 supplements.
P2Y purinoceptor 11 is a protein that in humans is encoded by the P2RY11 gene. The product of this gene, P2Y11, belongs to the family of G-protein coupled receptors. This family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. This receptor is coupled to the stimulation of the phosphoinositide and adenylyl cyclase pathways and behaves as a selective purinoceptor. Naturally occurring read-through transcripts, resulting from intergenic splicing between this gene and an immediately upstream gene (PPAN, encoding peter pan homolog), have been found. The PPAN-P2RY11 read-through mRNA is ubiquitously expressed and encodes a fusion protein that shares identity with each individual gene product.
=== Aviptadil === In the wake of the COVID-19 pandemic, scientists at Relief conducted initial studies into the efficacy of RLF-100 in treating severe COVID-19 patients. In June 2020, the U.S. Food and Drug Administration granted fast-track designation to RLF-100 for treatment of respiratory distress in COVID-19. In September 2020, Relief partnered with US-Israeli firm NRX Pharmaceuticals (formerly NeuroRx Inc) for the co-development of the drug and the co-ordination of US trials. In April 2021, a reformulated version of aviptadil, known as Zyesami, was included in a National Institutes of Health (NIH) sponsored Phase 3 trial with the aim of testing aviptadil against remdesivir. In May 2021, NRX submitted a request for an Emergency Use Authorization (EUA) to the US FDA for aviptadil's use in patients in intensive care. On 7 October 2021 Relief Therapeutics filed a lawsuit against NRX Pharmaceuticals and its CEO Dr. Jonathan Javitt in the Supreme Court of the State of New York, citing multiple alleged breaches of the collaboration agreement signed by the two companies for the co-development of aviptadil. On 4 November 2021 the FDA declined EUA for the drug, but committed to working with NRX to further develop it. On 29 November 2021, NRX announced that data analysis from the NIH-sponsored Phase 3 trial showed a fourfold increase in survival at 60 days for patients administered with Zyesami (Aviptadil) vs those who received placebo.
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.