nootropic raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-04-06. Anything still debated is marked as such rather than presented as settled.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
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.
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 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。
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.
== Principle == Many organic molecules contain multiple functional groups that may react under similar conditions. Protecting groups are therefore introduced temporarily to prevent unwanted reactions during synthesis. In an orthogonal protecting group strategy, different protecting groups are chosen so that each responds to a specific set of reaction conditions. For example, one protecting group may be removed by acidic conditions, while another may be removed by basic conditions. Because the removal of one group does not affect the other, the two groups are considered orthogonal.
She collaborated with the company again in February 2025, to promote the "Cherry Crush Zero Sugar" flavour, in which she and Jedward attempted a Guinness World Record to see how many post-it notes they could attach to her within a minute. The attempt, which was overseen by an adjudicator, saw them attach 30, failing to break the record of 70.
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During Duterte's tenure as mayor, Davao City experienced economic boom and a significant decrease in crime from being a conflict-ridden area between communists and right-wing groups during the 1970s and 1980s, and is constantly rated as among the safest in the country. The city also ranks high in the world according to crowdsourced survey site Numbeo, a narrative that gained currency in the national media, creating a widespread public perception that has been a significant factor in establishing support for his nationwide drug policy. The city was also awarded "Most Child-Friendly City for Highly-Urbanized Category" in 1998, 1999, 2013 and 2014. Under Duterte's watch, the city council imposed a prohibition on selling, serving, drinking, and consuming alcoholic beverages from 01:00 until 08:00 each morning. Duterte signed Executive Order No. 39, reducing the speed limits for all kinds of motor vehicles within the territorial jurisdiction of Davao City in the interest of public safety and order. Duterte also signed Executive Order No. 04 creating the implementing of rules and regulations for a new comprehensive anti-smoking ordinance. A firecracker ban was also implemented by the City Council through the support of Duterte. Davao acquired 10 ambulances for central 911 intended for medical emergencies and 42 mobile patrol vehicles and motorcycles for the Davao City Police Office. Duterte, through Executive Order No.
Sources: en.wikipedia.org
=== Mechanism of action === The specific mechanisms by which drotrecogin exerts its effect on survival in patients with severe sepsis is not completely understood. In vitro data suggest that activated protein C exerts an antithrombotic effect by inhibiting factors Va and VIIIa, and that it has indirect profibrinolytic activity by inhibiting plasminogen activator inhibitor-1 (PAI-1). In vitro data also suggest that activated protein C may exert an anti-inflammatory effect by inhibiting tumor necrosis factor production, by blocking leukocyte adhesion to selectins, and by limiting the thrombin-induced inflammatory responses within the microvascular endothelium.
=== Albania === The 2011 Albanian opposition demonstrations were a series of anti-government protests in cities around Albania following 18 months of political conflict over alleged electoral fraud by the opposition. Demonstrations were called for by parliamentary opposition parties, which include the Socialist Party and the Unity for Human Rights Party. The public outcry resulted in the resignation of the deputy prime minister. On 21 January, a protest in Tirana led to the killings of three demonstrators by the Republican Guard during a rally in front of Prime Minister Sali Berisha office, while fourth person died several days later. Parliamentary elections were held in Albania on 23 June 2013. The result was a victory for the Alliance for a European Albania led by the Socialist Party and its leader, Edi Rama. Incumbent prime minister Sali Berisha of the Democratic Party-led Alliance for Employment, Prosperity and Integration conceded defeat on 26 June, widely viewed as a sign of growing democratic maturity in Albania. The 2017 Albanian opposition protests were a series of anti-government protests, largely in Tirana, which centered around government corruption, the illicit drug situation in Albania, fear of electoral fraud in the parliamentary elections, and alleged manipulation of the voting process by the Socialist government. They were followed by the 2019 protests calling for the cancellation of the 2019 Albanian local elections, fresh elections, resignation of prime minister Edi Rama and his entire cabinet and the installation of a new technocrat government.
Activated protein C–protein C inhibitor (APC-PCI) is a complex of activated protein C (APC) and protein C inhibitor (PCI). It has been measured in coagulation testing to evaluate coagulation, thrombosis, and other cardiovascular complications. It is a marker of thrombin generation and indicates hypercoagulability or presence of thrombosis. Activated Protein C is a vitamin K-dependent serine protease that cleaves and inactivates Factor Va and Factor VIIIa, thus acting as an anticoagulant. Protein C Inhibitor is a 54-kilodalton glycoprotein of the serpin superfamily. Like other serpins, upon cleavage by PC, PCI undergoes a dramatic conformational rearrangement resulting in a stable covalent bond between the two proteins. The resulting PC-PCI protein dimer lacks enzyme activity and is permanently inactivated, an example of suicide inhibition. Formation of this complex is one of the major means of regulation of protein C activity, so that pro-coagulation and anticoagulant activities are kept in balance.
Mycosporine–like amino acids are rather small molecules (<400 Da). The structures of over 30 MAAs have been resolved and all contain a central cyclohexenone or cyclohexenimine ring and a wide variety of substitutions. The ring structure is thought to absorb UV light and accommodate free radicals. All MAAs absorb ultraviolet wavelengths, typically between 310 and 362 nm. They are considered to be amongst the strongest natural absorbers of UV radiation. It is this light absorbing property that allows MAAs to protect cells from the harmful UV-B and UV-A components of sunlight. Biosynthetic pathways of MAAs depend on the specific MAA molecule and the organism that is producing it. These biosynthetic pathways often share common enzymes and metabolic intermediates with pathways of the primary metabolism. An example is the shikimate pathway that is classically used to produce the aromatic amino acids (phenylalanine, tyrosine and tryptophan); with many intermediates and enzymes from this pathway utilized in MAA biosynthesis.
=== Chemical === Bohrium is the fifth member of the 6d series of transition metals and the heaviest member of group 7 in the periodic table, below manganese, technetium and rhenium. All the members of the group readily portray their group oxidation state of +7 and the state becomes more stable as the group is descended. Thus bohrium is expected to form a stable +7 state. Technetium also shows a stable +4 state whilst rhenium exhibits stable +4 and +3 states. Bohrium may therefore show these lower states as well. The higher +7 oxidation state is more likely to exist in oxyanions, such as perbohrate, BhO−4, analogous to the lighter permanganate, pertechnetate, and perrhenate. Nevertheless, bohrium(VII) is likely to be unstable in aqueous solution, and would probably be easily reduced to the more stable bohrium(IV). The lighter group 7 elements are known to form volatile heptoxides M2O7 (M = Mn, Tc, Re), so bohrium should also form the volatile oxide Bh2O7. The oxide should dissolve in water to form perbohric acid, HBhO4. Rhenium and technetium form a range of oxyhalides from the halogenation of the oxide. The chlorination of the oxide forms the oxychlorides MO3Cl, so BhO3Cl should be formed in this reaction. Fluorination results in MO3F and MO2F3 for the heavier elements in addition to the rhenium compounds ReOF5 and ReF7. Therefore, oxyfluoride formation for bohrium may help to indicate eka-rhenium properties.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.