A practical reference on lyophilized powder: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-29 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.
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。
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。
| 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 |
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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
== Veterinary uses == Eflornithine is effective in mice. Bacchi et al. 1980 found the drug to be curative in T. b. brucei infection of mouse and it is generally without toxicity. Klug et al. 2016 are of the opinion that this demonstrates good promise for oral treatment. However although Jansson et al. 2008 also effectively treated mice with it they found the pharmacokinetics of oral administration in rats very negative. Brun et al. 2010 are of the opinion that Jansson's results have killed the prospects for oral treatment.
=== Metabolism === 2-Coumarate reductase is an enzyme that converts o-coumaric acid to melilotic acid using reduced nicotinamide adenine dinucleotide (NADH). This enzyme participates in phenylalanine metabolism.
In the 2021–22 season Freiburg reached the final of the DFB-Pokal for the first time. In the league Freiburg finished sixth to qualify to the next season's Europa League, where they reached the round of 16. In the following season, they finished fifth in the league to achieve another direct qualification to the Europa League group stage, despite being in the Champions League spots most of the season; however, two consecutive losses against rivals RB Leipzig and Union Berlin had them drop down in the league table with two games remaining. In the DFB-Pokal of the same season, defeated Bayern Munich 2–1 in the quarter-finals, in an away match for the first time in their history, before losing in the semi-finals at home 1–5 to RB Leipzig.
== Design == The OM601 is closely related in design to the 5 cylinder OM602 and the 6 cylinder OM603 engine families of the same era. The OM601 uses an iron block with an aluminum head. The camshaft and fuel injection pump are driven by a duplex chain from the crankshaft; a separate single-row chain drives the oil pump from the crankshaft. Fuel is delivered via indirect injection through the pre-chamber. The mechanical injection pump features a 5,150 RPM (± 50 RPM) mechanical governor, automatic altitude compensation, and load-sensing automatic idle speed control; the injection pump is lubricated by a connection to the engine oil circulation system. The use of the block heater to aid in cold starting was recommended in climates where the temperature drops to below 10 °F (−12 °C) during the year.
Sources: en.wikipedia.org
==== Parafollicular cells ==== Scattered among follicular cells and in spaces between the spherical follicles are another type of thyroid cell, parafollicular cells. These cells secrete calcitonin and so are also called C cells.
== Federal Republic of Yugoslavia == Elections on a federal level were regularly held to elect the President of the Federal Republic of Yugoslavia as well as the Federal Assembly of the Federal Republic of Yugoslavia.
== See also == Animal testing on invertebrates Microbiome in the Drosophila gut Eating behavior in Insects (Measurement) Fruit flies in space Genetically modified insect Gynandromorphism JETLAG gene List of Drosophila databases Spätzle (gene) Time flies like an arrow; fruit flies like a banana Transgenesis Zebrafish – another widely-used model organism in scientific research Enhancer-FACS-seq
== Size of listings == The size of the darknet markets economy can be problematic to estimate. A study based on a combination of listing scrapes and feedback to estimate sales volume by researchers at Carnegie Mellon University captured some of the best data. A reviewed 2013 analysis put the Silk Road grossing $300,000 a day, extrapolating to over $100 million over a year. Subsequent data from later markets has significant gaps as well as complexities associated with analysing multiple marketplaces.
== S == sarcoplasmic reticulum - satellite DNA - scientific notation - SDS-PAGE - second messenger - second messenger system - secondary structure - secretin - selectin - sensory receptor - sequence (biology) - sequence homology - sequence motif - sequencing - serine - serotonin - serotonin receptor - serpin - sexual reproduction - SH3 domain - SI - sigma factor - signal peptide - signal recognition particle - signal sequence - signal transduction - sincalide - skeleton - skin - smooth ER - sodium channel - sodium-hydrogen antiporter - soluble - solution - solvation - solvent - somatomedin - somatomedin receptor - somatostatin - somatostatin receptor - somatotropin - somatotropin receptor - somatotropin-releasing hormone - somatropin - sp1 transcription factor - spectrin - spectroscopy - src gene - src-family kinase - SSRI - starch - stem cell - stereochemistry - steroid 17alpha-monooxygenase - steroid 21-monooxygenase - steroid receptor - stimulatory gs G-protein - stoichiometry - structural biology - structural domain - Structural formula - structural motif - substance P - substrate - sugar - sulfur - supercoil - superfamily - superoxide - surface immunoglobulin - surface plasmon resonance - suspension (chemistry) - synapse - synthetic vaccine - systems biology
Sources: en.wikipedia.org
The differing perceptions in the effects of ingesting beverages made from various plants containing caffeine could be explained by the fact that these beverages also contain varying mixtures of other methylxanthine alkaloids, including the cardiac stimulants theophylline and theobromine, and polyphenols that can form insoluble complexes with caffeine.
== Development == Prior to enamel formation, dentin formation begins through a process known as dentinogenesis, and this process continues throughout a person's life even after the tooth has fully developed. Events such as tooth decay and tooth wear can also initiate dentin formation. Dentinogenesis is initiated by the odontoblasts of the pulp. Odontoblasts are specialised cells that lay down an organic matrix known as pre-dentin. This predentin is subsequently mineralized into dentin. Mineralization of predentin begins at the dentinoenamel junction during tooth development and progresses towards the pulp of the tooth. After growth of predentin and maturation into dentin, the cell bodies of the odontoblasts remain in the pulp, along its outer wall, and project into tiny tubules in the dentin. Predentin is composed of 90% type I collagen and 10% non-collagenous proteins (including phosphoproteins, proteoglycans, growth factors, phosphatases such as alkaline phosphatase, and matrix metalloproteinases (MMPs)), and this composition is significantly altered when it is mineralized into dentin. See the Structure section for information about the composition of dentin.
== External links == GeneReviews/NCBI/NIH/UW entry on Cystinosis Human CTNS genome location and CTNS gene details page in the UCSC Genome Browser. Genetics Home Reference page on CTNS. Genetic Testing Registry.
These increases in coagulation factors may contribute to the development of stroke (see under § Side effects), but a precise association cannot be made at this stage. In a variety of clinical studies upon which FDA approval is based, Neumega showed effectivity in reducing thrombocytopenia in oncologic patients treated with myelosuppressant chemotherapeutic drugs as measured by significantly decreased need of platelet transfusions. Neumega is manufactured and sold by Wyeth. The drug is formulated in single-use vials containing 5 mg of oprelvekin (specific activity approximately 8 million units/mg) as a sterile, lyophilized powder. The FDA approved the drug in 1997.
Most of the supporters also stated that the death sentence should be deployed for drug crimes due to its strong deterrent effect. Shen's death sentence was subsequently upheld after he lost his appeal on 1 March 2024. When CNN covered the topic of Singapore's death penalty and Changi Prison in October 2024, it was noted that the death penalty continued to thrive with huge public support, and there were about 40 inmates on death row as of the time when CNN covered the issue exclusively. An inmate, a former schoolteacher who introduced himself as Matthew, stated he believed in the deterrent effect of the death penalty for drug trafficking; Matthew was then serving a seven-year jail term for non-capital drug charges. However, his sentiments were not shared by the family members of death row inmates who spoke to CNN. Haslinda Ismail, whose son Muhammed Izwan bin Borhan was sentenced to death for diamorphine trafficking, stated that she was devastated over the outcome and felt resentful towards the government for not giving her son a second chance; Izwan remained on death row awaiting to be hanged as of the time of writing. Similarly, Nazeri Lajim's sister, Nazira Lajim, who was an anti-death penalty activist, stated that she was sad and angry that her brother was executed despite her push for a life sentence, and likely due to her brother's hanging in 2022, Nazira encouraged her adult children to permanently leave Singapore and emigrate to Australia.
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.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。