The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-29. Anything still debated is marked as such rather than presented as settled.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
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。
=== Trials for cardiovascular health === In March 2024, the US Food and Drug Administration expanded the indication for semaglutide (brand name Wegovy) to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and who are either obese or overweight. This was based on a placebo-controlled randomized double-blind trial, which was sponsored by Novo Nordisk, on the efficacy and safety of semaglutide for this indication. 17,604 participant were randomly assigned to receive either semaglutide (Wegovy) or placebo. Participants in both groups also received standard-of-care medical treatment (e.g., management of blood pressure and cholesterol) and healthy lifestyle counseling (including diet and physical activity). The trial reported cumulative occurrence of major adverse cardiovascular events, a primary end-point event of the trial, for 569 of the 8803 patients in the semaglutide group, which were 6.5% of the participants, and for 701 of the 8801 patients in the placebo group, which were 8% of the participants, showing relative 18.8% less major adverse cardiovascular events, such as death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke, occurring for participants who had received semaglutide in the trial relative to those who had received placebo over the course of around 48 months, or 34.2±13.7 months, which was the mean (±SD) total duration of the participants in either group's exposure to the placebo or semaglutide during the trial.
==== Basis for different types of T-cell help ==== How these different methods operate, the forms of antigen expressed, and the different profiles of T-cell help is not understood. It was thought that the relatively large amounts of DNA used in IM injection were responsible for the induction of TH1 responses. However, evidence shows no dose-related differences in TH type. The type of T-cell help raised is determined by the differentiated state of antigen presenting cells. Dendritic cells can differentiate to secrete IL-12 (which supports TH1 cell development) or IL-4 (which supports TH2 responses). pDNA injected by needle is endocytosed into the dendritic cell, which is then stimulated to differentiate for TH1 cytokine (IL-12) production, while the gene gun bombards the DNA directly into the cell, thus bypassing TH1 stimulation.
== Treatment == Non-surgical treatments of FECD may be used to treat symptoms of early disease. Medical management includes topical hypertonic saline, the use of a hairdryer to dehydrate the precorneal tear film, and therapeutic soft contact lenses. Hypertonic saline draws water out of the cornea through osmosis. When using a hairdryer, the patient is instructed to hold it at an arm's length or directed across the face in a cold setting, to dry out the epithelial blisters. This can be done two or three times a day. Scleral lenses can improve vision when it is affected by irregularities on the surface of the cornea, but may stress the corneal endothelium. Corneal transplantation is the definitive treatment for FECD. The most common types of surgery for FECD are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), which account for over half of corneal transplants in the United States. Injection of cultured endothelial cells is under investigation and in a series of 11 patients in Japan with bullous keratopathy, was able to clear corneal edema.
Only two SSRIs are licensed for use with children in the UK, sertraline (Zoloft) and fluvoxamine (Luvox), for the treatment of obsessive–compulsive disorder. Fluoxetine is not licensed for this use. A 2007 comparison of aggression and hostility occurring during treatment with fluoxetine to placebo in children and adolescents found that no significant difference between the fluoxetine group and the placebo group. There is also evidence that higher rates of SSRI prescriptions are associated with lower rates of suicide in children, though since the evidence is correlational, the true nature of the relationship is unclear. A 2021 Swedish study, using a within-individual design, also found that young people (as well as adults) who have both attempted suicide and been prescribed SSRIs most commonly make the attempt before, rather than after, starting their SSRI prescription.
During the signing, Trump stated that the new recommendation "has to do with many subjects including autism in particular"; he and Robert F. Kennedy Jr., secretary of health and human services, made numerous references to autism throughout the signing. Health experts have criticized media reporting of the MMR-autism controversy for triggering a decline in vaccination rates. Before publication of Wakefield's article, the inoculation rate for MMR in the UK was 92%; after publication, the rate dropped to below 80%. In 1998, there were 56 measles cases in the UK; by 2008, there were 1348 cases, with two confirmed deaths. In Japan, the MMR triplet is not used. Immunity is achieved by a combination vaccine for measles and rubella, followed up later with a mumps only vaccine. This has had no effect on autism rates in the country, further disproving the MMR autism hypothesis.
Sources: en.wikipedia.org
=== Biochemical logic === The existence of more than one point of regulation indicates that intermediates between those points enter and leave the glycolysis pathway by other processes. For example, in the first regulated step, hexokinase converts glucose into glucose-6-phosphate. Instead of continuing through the glycolysis pathway, this intermediate can be converted into glucose storage molecules, such as glycogen or starch. The reverse reaction, breaking down, e.g., glycogen, produces mainly glucose-6-phosphate; very little free glucose is formed in the reaction. The glucose-6-phosphate so produced can enter glycolysis after the first control point. In the second regulated step (the third step of glycolysis), phosphofructokinase converts fructose-6-phosphate into fructose-1,6-bisphosphate, which then is converted into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. The dihydroxyacetone phosphate can be removed from glycolysis by conversion into glycerol-3-phosphate, which can be used to form triglycerides. Conversely, triglycerides can be broken down into fatty acids and glycerol; the latter, in turn, can be converted into dihydroxyacetone phosphate, which can enter glycolysis after the second control point.
== Further reading == Brady JE, Humiston GE & Heikkinen H (1980), "Chemistry of the Representative Elements: Part II, The Metalloids and Nonmetals", in General Chemistry: Principles and Structure, 2nd ed., SI version, John Wiley & Sons, New York, pp. 537–91, ISBN 0-471-06315-0 Chedd G (1969), Half-way Elements: The Technology of Metalloids, Doubleday, New York Choppin GR & Johnsen RH (1972), "Group IV and the Metalloids", in Introductory Chemistry, Addison-Wesley, Reading, Massachusetts, pp. 341–57 Dunstan S (1968), "The Metalloids", in Principles of Chemistry, D. Van Nostrand Company, London, pp. 407–39 Goldsmith RH (1982), "Metalloids", Journal of Chemical Education, vol. 59, no. 6, pp. 526527, doi:10.1021/ed059p526 Hawkes SJ (2001), "Semimetallicity", Journal of Chemical Education, vol. 78, no. 12, pp. 1686–87, doi:10.1021/ed078p1686 Metcalfe HC, Williams JE & Castka JF (1974), "Aluminum and the Metalloids", in Modern Chemistry, Holt, Rinehart and Winston, New York, pp. 538–57, ISBN 0-03-089450-6 Miller JS (2019), "Viewpoint: Metalloids – An Electronic Band Structure Perspective", Chemistry – A European Perspective, preprint version, doi:10.1002/chem.201903167 Moeller T, Bailar JC, Kleinberg J, Guss CO, Castellion ME & Metz C (1989), "Carbon and the Semiconducting Elements", in Chemistry, with Inorganic Qualitative Analysis, 3rd ed., Harcourt Brace Jovanovich, San Diego, pp. 742–75, ISBN 0-15-506492-4 Parveen N et al.
=== Essendon === On 28 September 2010, the rumours were confirmed when Essendon's chief executive officer, Ian Robson, and chairman, David Evans, announced at an official press conference that Hird would be the next senior coach of the Essendon Football Club on a four-year contract. Hird's coaching career began with the Bombers winning against triple preliminary finalists the Western Bulldogs in the first round. Wins against St Kilda, the Gold Coast (by a record margin of 139 points), West Coast and Brisbane Lions in the first eight rounds saw the Bombers in the top four by round eight, but a draw against Carlton, losses to Sydney and Collingwood and a five-game losing streak halfway through the season saw Essendon drop to tenth on the ladder after Round 14. Hird's team then won by four points against the previously undefeated Geelong in Round 15, whom assistant coach Mark Thompson was coaching against for the first time since his exit from the club. Prior to that match, Essendon had one of the worst records among current AFL clubs against Geelong in recent times, having only beaten the club once since 2003. Hird coached Essendon to the 2011 finals, where they lost against rivals Carlton in an elimination final at the MCG. At the start of the 2012 season, Essendon won eight of their first nine games (the only loss being by one point to Collingwood on ANZAC Day), at which point Essendon were in first position on the league ladder. The club then won 11 of their first 14 games but this was followed by seven consecutive losses until the end of the season.
=== Available forms === Trimix is available in several different formulations, including a gel that can be used topically, a gel that can be administered into the urethra, and an injectable form that is administered via intracavernosal injection (an injection at either side, not the base, of the penis).
Sources: en.wikipedia.org
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.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。