Everything below concerns lyophilised powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
The gateway hypothesis states that cannabis use increases the probability of trying "harder" drugs. The hypothesis has been hotly debated as it is regarded by some as the primary rationale for the United States prohibition on cannabis use. A Pew Research Center poll found that political opposition to marijuana use was significantly associated with concerns about the health effects and whether legalization would increase cannabis use by children. Some studies state that while there is no proof for the gateway hypothesis, young cannabis users should still be considered as a risk group for intervention programs. Other findings indicate that hard drug users are likely to be poly-drug users, and that interventions must address the use of multiple drugs instead of a single hard drug. Almost two-thirds of the poly drug users in the 2009–2010 Scottish Crime and Justice Survey used cannabis. The gateway effect may appear due to social factors involved in using any illegal drug. Because of the illegal status of cannabis, its consumers are likely to find themselves in situations allowing them to acquaint with individuals using or selling other illegal drugs. Studies have shown that alcohol and tobacco may additionally be regarded as gateway drugs; however, a more parsimonious explanation could be that cannabis is simply more readily available (and at an earlier age) than illegal hard drugs.
=== ADHD medication === CEO of the ASHP Dr. Paul Abramowitz reported that shortages in Adderall medication developed to a point where they were "demand-driven". Shortages beginning in October 2022 were caused or exacerbated by limited prescriptions amounts controlled by the Drug Enforcement Administration, coupled with over-diagnosis of ADHD and overprescription of Adderall. Scarcity continued in 2024 as a result of continually increased demand and supply chain problems, despite increases in production and distribution of Adderall. Patients and healthcare providers have expressed concerns about the impact on treatment plans for ADHD and narcolepsy, as many individuals rely on this medication for managing their symptoms.
== Evolutionary considerations == The role of prolonged cortical myelination in human evolution has been implicated as a contributing factor in some cases of demyelinating disease. Unlike other primates, humans exhibit a unique pattern of postpubertal myelination, which may contribute to the development of psychiatric disorders and neurodegenerative diseases that present in early adulthood and beyond. The extended period of cortical myelination in humans may allow greater opportunities for disruption in myelination, resulting in the onset of demyelinating disease. Furthermore, humans have significantly greater prefrontal white matter volume than other primate species, which implies greater myelin density. Increased myelin density in humans as a result of a prolonged myelination may, therefore, structure risk for myelin degeneration and dysfunction. Evolutionary considerations for the role of prolonged cortical myelination as a risk factor for demyelinating disease are particularly pertinent given that genetics and autoimmune deficiency hypotheses fail to explain many cases of demyelinating disease. As has been argued, diseases such as multiple sclerosis cannot be accounted for by autoimmune deficiency alone, but strongly imply the influence of flawed developmental processes in disease pathogenesis. Therefore, the role of the human-specific prolonged period of cortical myelination is an important evolutionary consideration in the pathogenesis of demyelinating disease.
Damage caused by the storm includes at Castle Douglas High School where the roof of the building was partially blown off. Coastguard searching for a commercial scallop diver, missing in Scapa Flow, Orkney since 27 November, find a body. A 19-year-old man is killed, and three other people injured, in a crash on the outskirts of Inverurie, Aberdeenshire. A 41-year-old woman, subsequently named as Michelle McLeod, is killed in a dog attack at a flat in Aberdeen. 8 December – Police Scotland confirm human remains have been found in the wreckage of a plane discovered in the North Sea, near Lerwick, Shetland. Scottish Labour suspends Cammy Day, the leader of Edinburgh City Council, pending the outcome of a police investigation into alleged inappropriate behaviour. 9 December – Cammy Day confirms he has stepped down as leader of Edinburgh City Council after Police Scotland launched an investigation into allegations he bombarded Ukrainian refugees with questions, including those of a sexual nature. BBC Scotland announces the launch of two new news programmes in early 2025: Reporting Scotland: News at Seven, a weeknight news bulletin presented by Laura Maciver and Amy Irons on the BBC Scotland channel from 6 January, and the Scotcast podcast with Martin Geissler launching on 13 January. 10 December – A Scottish Government spokesman confirms that First Minister John Swinney has spoken by phone with US President-elect Donald Trump for the first time since his re-election, and described the 20 minute discussion as "positive".
Sources: en.wikipedia.org
The fourth species of genus Gadus, Gadus chalcogrammus, is commonly called Alaska pollock or walleye pollock. But there are also less widespread alternative trade names highlighting the fish's belonging to the cod genus, like snow cod or bigeye cod.
2.4×1034 years for decay to a positron and a neutral pion (p → e+ + π0), 1.6×1034 years for decay to an antimuon and a neutral pion (p → μ+K0), 0.59×1034 years for decay to an muon antineutrino and a positive kaon (p → ν̄K+). Two Nobel prizes for neutrino physics were awarded to scientists based on work using experimental facilities originally designed to detect proton decay. In 2002, Masatoshi Koshiba was awarded "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos", by upgrading the KamiokaNDE experiment. (sharing half prize with Raymond Davis Jr. for the same motivations).T. Kajita of the Super-Kamiokane collaboration was awarded the 2015 Nobel Prize "for the discovery of neutrino oscillations, which shows that neutrinos have mass", jointly to Art McDonald of the SNO experiment.
The duration of estradiol esters in oil solution by intramuscular injection is dose-dependent. With estradiol valerate, it is reported that a dose of 5 mg has a duration of 7 to 8 days, 10 mg a duration of 10 to 14 days, 40 mg a duration of 2 to 3 weeks, and 100 mg a duration of 3 to 4 weeks. High doses of estradiol valerate, such as 40 mg per week, can achieve pregnancy levels of estradiol. A study of pseudopregnancy with intramuscular injections of 40 mg/week estradiol valerate and 250 mg/week hydroxyprogesterone caproate observed estradiol levels of about 2,500 to 3,000 pg/mL.
== Society and culture == A team of researchers led by Changhan Lee, a member of the Pinchas Cohen laboratory at the USC Davis School of Gerontology, discovered MOTS-c in 2015. Subsequent research by Lee and colleagues linked administration of MOTS-c to improved physical fitness, decreased obesity, and longer healthy lifespans in mice. MOTS-c is not approved to treat any medical condition and is banned by the World Anti-Doping Agency, explicitly beginning in 2024. Despite a lack of robust human data, usage as an injectable supplement as part of the "peptide stacking" trend has been reported.
While P-51s used 110-US-gallon (420 L) drop tanks over Europe, for Japan they frequently used 165-US-gallon (620 L) drop tanks which allowed more loitering time over Japan. While USAAF B-17 and B-24 bombers in Europe were arranged in combat box formations, over Japan the B-29s formed a stream that could stretch up to 200 miles. The escorting P-51s formed three Tar-Cap (Target Combat Air Patrol) squadrons, two squadrons flying on one side of the B-29 stream and the third on the other side, each squadron being 2,000 feet above and 4,000 to 5,000 feet laterally from the bomber stream. Compared to its Japanese adversaries, the P-51 largely outclassed the Imperial Japanese Army Air Service's aging A6M Zero (the most numerous Japanese fighter available), as the A6M's poor high-altitude performance put it at a disadvantage in the P-51's favorable performance envelope. When the P-51 was used for interdiction or strike missions, the A6M was slower but could still out-turn or out climb the P-51 at low to medium altitude. Newer Japanese designs were potent but too few in number. The Kawanishi N1K-J Shiden was fast and agile, but not effective as an interceptor due to a poor rate of climb and reduced engine performance at high altitude. The Imperial Japanese Army Air Service's Nakajima Ki-84 Hayate had performance and an operation ceiling that could match the P-51, however the Ki-84 suffered from manufacturing defects, and its high-maintenance Nakajima Homare engine could not reach its full potential due to lack of ample high-octane fuel.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。