This is a working overview of Semax, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-11-06. Anything still debated is marked as such rather than presented as settled.
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.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
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。
== Side effects == Side effects of benzimidazole derived opioids are likely to be similar to those of fentanyl, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Isotonitazene has been detected in multiple fatalities in Europe since March 2019 and in the U.S. since August 2019, as reported by NPS Discovery, the Center for Forensic Science Research and Education, and NMS Labs.
==== Hospitalized patients ==== Remdesivir was approved for medical use in the United States in October 2020. The US Food and Drug Administration (FDA) approved remdesivir based on the agency's analysis of data from three randomized, controlled clinical trials that included participants hospitalized with mild-to-severe COVID‑19. The FDA granted approval and reissued the revised EUA to Gilead Sciences Inc. The FDA approved remdesivir based primarily on evidence from three clinical trials (NCT04280705, NCT04292899, and NCT04292730) of 2043 hospitalized participants with COVID‑19. The trials were conducted at 226 sites in 17 countries including the United States. In November 2020, the World Health Organization (WHO) updated its guideline on therapeutics for COVID‑19 to include a conditional recommendation against the use of remdesivir, triggered by results from the WHO Solidarity trial. Meanwhile, the Public Health Agency of Canada's COVID‑19 Clinical Pharmacology Task Group recommended that remdesivir only be administered to hospitalized patients as part of a randomized controlled trial due to limited information on risks and benefits. In January 2022, the Canadian component of the WHO Solidarity Trial reported that in-hospital people with COVID‑19 treated with remdesivir had 17% lower relative risk of death (18.7% versus 22.6% death rates) and 47% reduced relative risk for needing oxygen and mechanical ventilation (8.0% versus 15.0%) compared to people receiving standard-of-care treatments.
Bancroft, EA (October 2007). "Antimicrobial resistance: it's not just for hospitals". JAMA. 298 (15): 1803–1804. doi:10.1001/jama.298.15.1803. PMC 2536104. PMID 17940239. Larson, E (2007). "Community factors in the development of antibiotic resistance". Annual Review of Public Health. 28 (1): 435–447. doi:10.1146/annurev.publhealth.28.021406.144020. PMID 17094768.
=== Endothelial colony forming cell === Endothelial colony forming cells are a late outgrowth cell type; that is, they are only isolated after significantly longer culture than CFU-Hill cells. ECFCs are isolated by plating peripheral blood mononuclear fraction on collagen-coated plates, removing non-adherent cells, and culturing for weeks until the emergence of colonies with a distinctive cobblestone morphology. These cells are phenotypically similar to endothelial cells and have been shown to create vessel-like structures in vitro and in vivo. In 2019, David Smadja described a standardized protocol for the isolation and culture of endothelial colony-forming cells (ECFCs) in humans. This was followed in 2023 by a publication surveying laboratory practices among teams working with these cells, conducted under the auspices of the International Society on Thrombosis and Haemostasis Vascular Biology Scientific Subcommittee. In 2025, a review emphasized the unique vasculogenic and immunomodulatory properties of cord blood-derived ECFCs (CB-ECFCs), highlighting their high proliferative capacity, immune-privileged status, and therapeutic potential in vascular regeneration and tissue engineering.
Sources: en.wikipedia.org
Trump's second term foreign policy has been described as a mixture of both imperialist and expansionist policies. He engaged in a realist and isolationist "America First" foreign policy agenda. His administration favored hard power to achieve foreign policy goals, and dismantled or withdrew support from domestic and international organizations dedicated to advancing American soft power. The moves were described as ceding American global influence and creating a void filled by Russia and China. His relations with allies were transactional and ranged from indifference to hostility, and he threatened them with economic tariffs or annexation. He was described as taking the side of Russia in the Russian invasion of Ukraine, and overseeing a rupture of the post-1945 rules-based liberal international order and abandonment of multilateralism. Michael Klare wrote that containing the influence of China and preventing the rise of any rival power is the central foreign policy objective of the administration. Trump has attempted to deepen the U.S.-India partnership. Trump's administration saw large drops in global public opinion of the U.S. Countries like Canada, Germany, the U.K., Denmark, and Finland warned their citizens about traveling to the U.S.
=== SB Pharmco Puerto Rico === In 2010, the US Department of Justice announced that GSK would pay a US$150 million criminal fine and forfeiture, and a civil settlement of US$600 million under the False Claims Act. The fines stemmed from production of improperly made and adulterated drugs from 2001 to 2005, at GSK's subsidiary, SB Pharmco Puerto Rico Inc., in Cidra, Puerto Rico, which at the time produced US$5.5 billion of products each year. The drugs involved were Kytril, an antiemetic; Bactroban, used to treat skin infections; Paxil, the anti-depressant; and Avandamet, a diabetes drug. GSK closed the factory in 2009. The case began in 2002, when GSK sent experts to fix problems cited by the FDA. The lead inspector recommended recalls of defective products, but they were not authorised; she was fired in 2003, and filed a whistleblower lawsuit. In 2005, federal marshals seized US$2 billion worth of products, the largest such seizure in history. In the 2010 settlement SB Pharmco pleaded guilty to criminal charges, and agreed to pay US$150 million in a criminal fine and forfeiture, at that time the largest such payment ever by a manufacturer of adulterated drugs, and US$600 million in civil penalties to settle the civil lawsuit.
=== Ribosomal translocation === Macrolides, clindamycin and aminoglycosides (with all these three having other potential mechanisms of action as well), have evidence of inhibition of ribosomal translocation. Fusidic acid prevents the turnover of elongation factor G (EF-G) from the ribosome. Ricin inhibits elongation by enzymatically modifying an rRNA of the eukaryotic 60S ribosomal subunit.
=== Synthesis === Loperamide is synthesized starting from the lactone 3,3-diphenyldihydrofuran-2(3H)-one and ethyl 4-oxopiperidine-1-carboxylate, on a lab scale. On a large scale a similar synthesis is followed, except that the lactone and piperidinone are produced from cheaper materials rather than purchased.
In his first Senate campaign, Biden had expressed support for busing to remedy de jure segregation, as in the South, but opposed its use to remedy de facto segregation arising from racial patterns of neighborhood residency, as in Delaware; he opposed a proposed constitutional amendment banning busing entirely. Biden supported a 1976 measure forbidding the use of federal funds for transporting students beyond the school closest to them. He co-sponsored a 1977 amendment closing loopholes in that measure, which President Carter signed into law in 1978. Biden became ranking minority member of the Senate Judiciary Committee in 1981. He was a Democratic floor manager for the successful passage of the Comprehensive Crime Control Act in 1984. His supporters praised him for modifying some of the law's worst provisions, and it was his most important legislative accomplishment to that time. In 1994, Biden helped pass the Violent Crime Control and Law Enforcement Act, which included a ban on assault weapons, and the Violence Against Women Act, which he has called his most significant legislation. The 1994 crime law was unpopular among progressives and criticized for resulting in mass incarceration; Biden later expressed regret for passing the bill. Biden voted for a 1993 provision that deemed homosexuality incompatible with military life, thereby banning gay people from serving in the armed forces.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.