The short version of Semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-02 and is reviewed periodically as new material appears.
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 peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
| 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 |
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
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 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。
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
A December 2023 Gallup poll found a record low 28% of Americans reporting that they were satisfied with the way democracy is working in the country. In the weeks before the election, surveys showed that many favored a concession speech from the losing presidential candidate, had broad concerns about the state of democracy and were fearful of future acts of political violence. Surveys from the National Election Pool and VoteCast highlight the role the issue of democracy played in the election. According to results provided by the National Election Pool, 34% percent of voters said that the state of democracy mattered most to their vote. The poll found that 25% of those who cast a ballot said that democracy in the U.S. is secure, while 73% said it is threatened. VoteCast found that half of voters identified the future of democracy as the single most important factor for their vote. 9 in 10 Harris voters who said that democracy was the single most important factor expressed concern that electing Trump would bring the country closer to authoritarianism. About 80% of Trump voters who chose democracy as their top issue expressed concern about a Harris presidency becoming authoritarian.
In addition to its Support Base in Djibouti, the PLA operates a base in Tajikistan and a listening station in Cuba. The Espacio Lejano Station in Argentina is operated by a PLA unit. The PLAN has also undertaken rotational deployments of its warships at the Ream Naval Base in Cambodia. The People's Republic of China has sent the PLA to various hotspots as part of China's role as a prominent member of the United Nations. Such units usually include engineers and logistical units and members of the paramilitary People's Armed Police and have been deployed as part of peacekeeping operations in Lebanon, the Republic of the Congo, Sudan, Ivory Coast, Haiti, and more recently, Mali and South Sudan.
In teleosts, the conus arteriosus is very small and can more accurately be described as part of the aorta rather than of the heart proper. The conus arteriosus is not present in any amniotes, presumably having been absorbed into the ventricles over the course of evolution. Similarly, while the sinus venosus is present as a vestigial structure in some reptiles and birds, it is otherwise absorbed into the right atrium and is no longer distinguishable.
=== Opisthoglyphous colubrids === Biologists had long known that some snakes had rear fangs, 'inferior' venom injection mechanisms that might immobilize prey; although a few fatalities were on record, until 1957, the possibility that such snakes were deadly to humans seemed at most remote. The deaths of two prominent herpetologists, Robert Mertens and Karl Schmidt, from African colubrid bites, changed that assessment, and recent events reveal that several other species of rear-fanged snakes have venoms that are potentially lethal to large vertebrates. Boomslang (Dispholidus typus) and twig snake (Thelotornis spp.) venoms are toxic to blood cells and thin the blood (hemotoxic, hemorrhagic). Early symptoms include headaches, nausea, diarrhea, lethargy, mental disorientation, bruising, and bleeding at the site and all body openings. Exsanguination is the main cause of death from such a bite. The boomslang's venom is the most potent of all rear-fanged snakes in the world based on LD50. Although its venom may be more potent than some vipers and elapids, it causes fewer fatalities owing to various factors (for example, the fangs' effectiveness is not high compared with many other snakes, the venom dose delivered is low, and boomslangs are generally less aggressive in comparison to other venomous snakes such as cobras and mambas). Symptoms of a bite from these snakes include nausea and internal bleeding, and one could die from a brain hemorrhage and respiratory collapse.
Sources: en.wikipedia.org
In Switzerland, a special authorization program allows limited medical use of substances like LSD for patients with serious, treatment-resistant conditions, with patients treated under physician supervision.
=== Photolysis and thermolysis === Photolysis or thermolysis of mononuclear carbonyls generates di- and polymetallic carbonyls such as diiron nonacarbonyl (Fe2(CO)9). On further heating, the products decompose eventually into the metal and carbon monoxide.
== Products == Several types of products, including retail bags, carton liners, bin bags, lidding films and flow pack have been developed from MA/MH films and are commercially available. Each product type is uniquely engineered for the specific produce type (and in some cases, the produce variety) to be packaged. This is done through a rigorous process of developing, testing, adjusting and retesting each MA\MH product both in the lab and in commercial trials. This meticulous process is repeated for each combination of produce and packaging type because of the many factors involved in developing a successful MA/MH packaging. These factors are "storage and shipment temperature, product respiration rate and quotient, response to levels of CO2, O2 and humidity, and product weight. Hence, film packaging that is adequate for consumer packages is not always suitable for bulk packaging and vice versa."
July 23, 2010: United Kingdom The ONS released preliminary figures showing that economic growth had accelerated from 0.3% in Q1 2010 to 1.1% in Q2. This is almost double the original forecast of 0.6% growth, and the news is a welcome surprise. In late August, this figure was revised up to 1.2% growth as a result of greater construction output. However, large budget cuts are being put into action by the new coalition government to tackle the £163bn budget deficit that the country faces.
=== Environmental impacts === There are several negative environmental impacts due to the modern day textile industry such as the discharge of textile dyes and pigments into wastewater, greenhouse gas emissions from production, energy and resource intensive production, and large amounts of landfill waste. Water pollution is the greatest environment concern since pigments and textile dyes do not naturally biodegrade over time, which causes direct health concerns for both humans and ecosystem wildlife.
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.
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.