Semax comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-08-12. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
| 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 |
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。
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
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.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
==== Axon injury ==== For severe nerve entrapment, nerve axons can be injured to the point of destruction. Axon injury is also known as axonmetesis or a Sunderland type 2 nerve injury where the endoneurial tubes are preserved. If an axon is injured, the axonal transport system may not function. Since the axon depends on its connection to the cell body, the disrupted axonal transport will cause segmental death of the axon distal to the injury site in a process called Wallerian degeneration. This will result in a complete conduction block, leading to muscle weakness (motor nerve) or numbness (sensory nerve). Provided that the endoneurial tube is not disrupted, there is still a pathway for the axon at the injury site to regrow, but the growth is very slow (approximately 1mm/day). Recovery can take months and is often partial.
==== Cardiovascular ==== Methamphetamine is a sympathomimetic drug that causes vasoconstriction and tachycardia. Methamphetamine also promotes abnormal extra heartbeats and irregular heart rhythms, which may be life-threatening.
The U.S. 101st Airborne Division and ARVN 1st Division launch Operation Apache Snow in the A Shau Valley. The operation results in 977 PAVN killed and five captured while U.S. losses were 113 killed and ARVN losses were 31 killed. Most of the U.S. casualties were in the Battle of Hamburger Hill from May 13–20 where U.S. forces attacked heavily fortified PAVN positions on Hill 937. 630 PAVN, 72 U.S. and 31 ARVN were killed in the fighting for Hill 937.
== Clinicians == Physician Bachelor of Medicine, Bachelor of Surgery (MBBS) Doctor of Medicine (M.D.) Doctor of Osteopathic Medicine (D.O.) Dentist Bachelor of Dental Surgery (BDS) Doctor of Dental Medicine (DMD) Doctor of Dental Surgery (DDS) Optometrist Doctor of Optometry (OD) Podiatrist Doctor of Podiatry (DPM) Chiropractor Doctor of Chiropractic (DC) Physician Assistant (PA) Doctor of Medical Science (D.Med.Sc.), (D.M.Sc.) Master of Medical Science (M.Med.Sc), (M.M.Sc.) Master of Physician Assistant Studies (M.P.A.S.) Professional (Second-entry) Bachelor of Science in Physician Assistant (B.Sc.PA.), (B.H.Sc.PA) Pharmacist (R.Ph.) Doctor of Pharmacy (PharmD) Master of Pharmacy (MPharm) Bachelor of Pharmacy (B.Pharm)
Sources: en.wikipedia.org
It is theoretically a sound hypothesis that the spermatogenesis can be increased by indirectly stimulating FSH and LH secretions from the pituitary gland. However, for this to fructify, it requires the use of testosterone antagonist to nullify the negative feedback effect of circulating testosterone on the release of FSH and LH, thus augmenting the secretion of testosterone and spermatogenesis. Unfortunately, a testosterone antagonist will be unacceptable to males, as it may reduce secondary sexual functions including erection and ejaculation that is vital for the successful fertilization. However, while bicalutamide does not appear to adversely influence testicular spermatogenesis, and healthy sperm can be produced within the testes during bicalutamide monotherapy, AR antagonists may be able to interfere with male fertility via interference with androgen signaling beyond the testes. The maturation as well as transport of sperm occurs not only in the testes but also outside of the testes in the epididymides and vas deferens, and these processes in these tissues are dependent on AR signaling similarly to testicular spermatogenesis. However, whereas androgen levels are extremely high in the testes, this is not true in the epididymides and vas deferens. As androgen levels are relatively low in these tissues, at least compared to the testes, bicalutamide may be able to block AR signaling in these parts of the body to an extent that is sufficient to interfere with male fertility.
=== Impersonation attempts === Despite a seven-page document written by Twitter's content moderation team, on November 9, Twitter Blue launched with verification exclusively on iOS. Upon introducing paid verification, various individuals in sports Twitter were impersonated, such as sports writer Adam Schefter and basketball player LeBron James, with tweets announcing the supposed ousting of Las Vegas Raiders head coach Josh McDaniels or James' trade from the Los Angeles Lakers, respectively. As impersonation accounts began appearing for Nintendo and Tesla—the latter being owned by Musk—the official label returned. Other individuals and companies impersonated include former president Donald Trump, video game company Valve, and former New York City mayor Rudy Giuliani. One account impersonating the beverage corporation PepsiCo praised the superiority of Coca-Cola. Twitter paused signups for Twitter Blue on November 11; according to a Slack message obtained by Platformer reporter Zoë Schiffer, the company paused subscriptions to deal with impersonation attempts. Musk believed that impersonation would be resolved if Apple handed over the credit card information of Twitter Blue subscribers; then head of trust and safety Yoel Roth explained that Apple would not oblige to such a request. The Washington Post published a report on November 11 detailing how reporter Geoffrey Fowler was, with permission from United States senator Ed Markey, impersonating a U.S.
Aggressive periodontitis is distinguished from the chronic form mainly by the faster rate of progression. Loss of attachment may progress despite good oral hygiene and in the absence of risk factors such as smoking. Aggressive periodontitis may occur in younger persons and there may a genetic aspect, with the trait sometimes running in families.
The cycle is present in microorganisms that cause disease but is absent in mammals, for example humans. There is a strong plausibility of the development of antibiotics that would attack the glyoxylate cycle, which would kill the disease-causing microorganisms that depend on the cycle for their survival, yet would not harm humans where the cycle, and thus the enzymes that the antibiotic would target, are absent.
The Hukbalahap movement has deep roots in the Spanish encomienda, a system of grants to reward soldiers who had conquered New Spain, established in 1570. This developed into a system of exploitation. In the 19th century, Filipino landlordism, under the Spanish colonization, arose further abuses. After the opening of ports in Manila, Luzon's economy was transformed to meet the demands for exports of rice, sugar, and tobacco. Landowners increased the demands on farmers who rented parcels of land. These demands included increased rents, demands for proceeds from the sale of crops, and predatory lending agreements to fund farm improvements. Only after the coming of the Americans were reforms initiated to lessen tensions between tenants and landlords. The reforms, however, did not solve the problems, and with growing political consciousness produced by education, peasants began to unite under educated but poor leaders. The most potent of these organizations was the Hukbalahap, which began as a resistance organization against the Japanese but ended as an anti-government resistance movement in 1946.
Sources: en.wikipedia.org
=== Thioredoxin reductase === Thioredoxin reductase is also a key component of antioxidant defense. Although enzymes carrying out this function is found in most forms of life, the high-molecular-weight selenoprotein version found in animals evolved separately from the more common low-molecular-weight version. This version appears as a branch within the glutathione reductases, again a key component of antioxidant defense.
=== Translation initiation === Protein synthesis is primarily regulated at the stage of translation initiation. In eukaryotes, the canonical initiation pathway requires at least 12 protein initiation factors, some of which are themselves large complexes. The structures of the 40S:eIF1 and 60S:eIF6 complexes provide first detailed insights into the atomic interactions between the eukaryotic ribosome and regulatory factors. eIF1 is involved in start codon selection, and eIF6 sterically precludes the joining of subunits. However, structural information on the eukaryotic initiation factors and their interactions with the ribosome is limited and largely derived from homology models or low-resolution analyses. Elucidation of the interactions between the eukaryotic ribosome and initiation factors at an atomic level is essential for a mechanistic understanding of the regulatory processes, but represents a significant technical challenge, because of the inherent dynamics and flexibility of the initiation complexes. The first structure of the mammalian pre initiation complex was done by cryo-electron microscopy. Other structures of initiation complexes followed soon, driven by cryo-EM technical improvements. Those structures will help better understand the process of translation initiation in eukaryotes.
Delta waves are high amplitude neural oscillations with a frequency between 0.5 and 4 hertz. Delta waves, like other brain waves, can be recorded with electroencephalography (EEG). They are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and aid in characterizing the depth of sleep. Suppression of delta waves leads to impaired body recovery, reduced brain restoration, and poorer sleep.
=== Cross-activity === Epitopes are sometimes cross-reactive. This property is exploited by the immune system in regulation by anti-idiotypic antibodies (originally proposed by Nobel laureate Niels Kaj Jerne). If an antibody binds to an antigen's epitope, the paratope could become the epitope for another antibody that will then bind to it. If this second antibody is of IgM class, its binding can upregulate the immune response; if the second antibody is of IgG class, its binding can downregulate the immune response.
== Change of properties with temperature == All materials change with temperature, but superheated water exhibits greater changes than would be expected from temperature considerations alone. Viscosity and surface tension of water drop and diffusivity increases with increasing temperature.
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.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.