A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-02-17. Anything still debated is marked as such rather than presented as settled.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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。
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==== Bupropion (Wellbutrin) ==== The company was also fined for promoting Wellbutrin (bupropion) – approved at the time for major depressive disorder and also sold as a smoking-cessation aid, Zyban – for weight loss and the treatment of attention deficit hyperactivity disorder, sexual dysfunction and substance addiction. GSK paid doctors to promote these off-label uses, and set up supposedly independent advisory boards and Continuing Medical Education programmes.
=== Robotic, mobile laboratory operators and remote-controlled laboratories === In July 2020 scientists reported the development of a mobile robot chemist and demonstrate that it can assist in experimental searches. According to the scientists their strategy was automating the researcher rather than the instruments – freeing up time for the human researchers to think creatively – and could identify photocatalyst mixtures for hydrogen production from water that were six times more active than initial formulations. The modular robot can operate laboratory instruments, work nearly around the clock, and autonomously make decisions on his next actions depending on experimental results. There is ongoing development of "remote controlled laboratories" that automatically perform many life sciences experiments per day and can be operated, including in collaboration, from afar.
Sources: en.wikipedia.org
== Awards and recognition == David Rumbough Award for Scientific Achievement, Juvenile Diabetes Foundation (1977) Eli Lilly Award for Research, American Diabetes Association (1981) Cristobal Diaz Award for Research, International Diabetes Federation (1988) Banting Medal for Distinguished Scientific Achievement, American Diabetes Association (1993) Solomon Berson Distinguished Lecture, American Physiological Society (1997) Albert Renold Award, American Diabetes Association (1998) Dorothy Hodgkin Award, British Diabetes Association (1999) Fred Conrad Koch Award for Distinguished Contributions to Endocrinology, Endocrine Society (2000) Hamdan Award for Medical Research Excellence, awarded by Sheikh Hamdan bin Rashid Al Maktoum Award for Medical Sciences, Dubai, United Arab Emirates (2000) Lawson Wilkins Award Lecture, Pediatric Endocrine Society (2001) Rolf Luft Award Lecture, Karolinska Institute, Stockholm, Sweden (2001) Steven C. Beering Award for Advancement of Biomedical Science, Indiana University (2002) J.
=== Specific activity === The specific activity of an enzyme is another common unit. This is the activity of an enzyme per milligram of total protein (expressed in μmol min−1 mg−1). Specific activity gives a measurement of enzyme purity in the mixture. It is the micro moles of product formed by an enzyme in a given amount of time (minutes) under given conditions per milligram of total proteins. Specific activity is equal to the rate of reaction multiplied by the volume of reaction divided by the mass of total protein. The SI unit is katal/kg, but a more practical unit is μmol/(mg*min). Specific activity is a measure of enzyme processivity (the capability of enzyme to be processed), at a specific (usually saturating) substrate concentration, and is usually constant for a pure enzyme. An active site titration process can be done for the elimination of errors arising from differences in cultivation batches and/or misfolded enzyme and similar issues. This is a measure of the amount of active enzyme, calculated by e.g. titrating the amount of active sites present by employing an irreversible inhibitor. The specific activity should then be expressed as μmol min−1 mg−1 active enzyme. If the molecular weight of the enzyme is known, the turnover number, or μmol product per second per μmol of active enzyme, can be calculated from the specific activity. The turnover number can be visualized as the number of times each enzyme molecule carries out its catalytic cycle per second.
LDL particles are the major blood cholesterol carriers. Each one contains approximately 1,500 molecules of cholesterol ester. LDL particle shells contain just one molecule of apolipoprotein B100, recognized by LDL receptors in peripheral tissues. Upon binding of apolipoprotein B100, many LDL receptors concentrate in clathrin-coated pits. Both LDL and its receptor form vesicles within a cell via endocytosis. These vesicles then fuse with a lysosome, where the lysosomal acid lipase enzyme hydrolyzes the cholesterol esters. The cholesterol can then be used for membrane biosynthesis or esterified and stored within the cell, so as to not interfere with the cell membranes. LDL receptors are used up during cholesterol absorption, and its synthesis is regulated by SREBP, the same protein that controls the synthesis of cholesterol de novo, according to its presence inside the cell. A cell with abundant cholesterol will have its LDL receptor synthesis blocked, to prevent new cholesterol in LDL particles from being taken up. Conversely, LDL receptor synthesis proceeds when a cell is deficient in cholesterol. When this process becomes unregulated, LDL particles without receptors begin to appear in the blood. These LDL particles are oxidized and taken up by macrophages, which become engorged and form foam cells. These foam cells often become trapped in the walls of blood vessels and contribute to atherosclerotic plaque formation. Differences in cholesterol homeostasis affect the development of early atherosclerosis (carotid intima-media thickness).
Sources: en.wikipedia.org
== Bibliography == Cook, Nigel (2013), "10.1 Introduction; the role of fomites in the virus transmission", Viruses in Food and Water: Risks, Surveillance and Control, Cambridge: Woodhead Publishing, pp. 205–215, ISBN 978-0-85709-887-0 Bennett, John V.; Jarvis, William Robert; Brachman, Philip S. (2007), "Chapter 19: The Inanimate Environment", Bennett & Brachman's Hospital Infections, Philadelphia: Lippincott Williams & Wilkins, p. 277, ISBN 978-0-7817-6383-7 Fortuine, Robert (2000), The Words of Medicine: Sources, Meanings, and Delights, Springfield: Charles C Thomas Publisher, p. 53, ISBN 0398071322 Larson, Elaine L.; Liverman, Catharyn T. (2011), "Understanding the Risk to Healthcare Personnel: Fomite Persistence", Preventing Transmission of Pandemic Influenza and Other Viral Respiratory Diseases: Personal Protective Equipment for Healthcare Personnel: Update 2010, Washington: National Academies Press, p. 41, ISBN 978-0-309-16254-8 Shors, Teri (2017), "Clinical Signs and Symptoms of Human Herpersviruses", Understanding Viruses, Wisconsin: Jones & Bartlett Learning, ISBN 978-1-284-02592-7
1883-1897 Charles Roy - Professor of Pathology & Head of Department 1897-1898 Alfredo Kanthack - Professor of Pathology & Head of Department 1899-1922 German Sims Woodhead - Professor of Pathology & Head of Department 1922-1961 Henry Roy Dean - Professor of Pathology & Head of Department 1962-1975 Ronald Greaves - Professor of Pathology & Head of Department 1975-1987 Peter Wildy - Professor of Pathology & Head of Department 1987-1998 Malcolm Ferguson-Smith - Professor of Pathology & Head of Department 1998-2011 Andrew Wyllie - Professor of Pathology & Head of Department 2011-2022 Geoffrey Smith - Professor of Pathology & Head of Department 2022- Heike Laman - Head of Department (re-elected in 2025) 2023- Adrian Liston - Professor of Pathology
Breathing devices include the use of a CPAP machine. With proper use, CPAP improves outcomes. Evidence suggests that CPAP may improve sensitivity to insulin, blood pressure, and sleepiness. Long-term compliance, however, is an issue with more than half of people not appropriately using the device. In 2017, only 15% of potential patients in developed countries used CPAP machines, while in developing countries, well under 1% of potential patients used CPAP. Without treatment, sleep apnea may increase the risk of heart attack, stroke, diabetes, heart failure, irregular heartbeat, obesity, and motor vehicle collisions. OSA is a common sleep disorder. A large analysis in 2019 of the estimated prevalence of OSA found that OSA affects 936 million—1 billion people between the ages of 30–69 globally, or roughly every 1 in 10 people, and up to 30% of the elderly. Sleep apnea is somewhat more common in men than women, roughly a 2:1 ratio of men to women, and in general more people are likely to have it with older age and obesity. Other risk factors include being overweight, a family history of the condition, allergies, and enlarged tonsils.
Sources: en.wikipedia.org
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.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.