This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-26 and is reviewed periodically as new material appears.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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。
| 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 |
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.
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.
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.
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.
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 is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Biosecurity and Nanoscience Laboratory. Researchers apply advances in nanoscience to develop novel technologies for the detection, identification, and characterization of harmful biological pathogens (viruses, spores, and bacteria) and chemical toxins. Center for Accelerator Mass Spectrometry: LLNL's Center for Accelerator Mass Spectrometry (CAMS) develops and applies a wide range of isotopic and ion-beam analytical tools used in basic research and technology development, addressing a spectrum of scientific needs important to the Laboratory, the university community, and the nation. CAMS is the world's most versatile and productive accelerator mass spectrometry facility, performing more than 25,000 AMS measurement operations per year. High Explosives Applications Facility and Energetic Materials Center: At HEAF, teams of scientists, engineers, and technicians address nearly all aspects of high explosives: research, development and testing, material characterization, and performance and safety tests. HEAF activities support the Laboratory's Energetic Materials Center, a national resource for research and development of explosives, pyrotechnics, and propellants. National Atmospheric Release Advisory Center: NARAC is a national support and resource center for planning, real-time assessment, emergency response, and detailed studies of incidents involving a wide variety of hazards, including nuclear, radiological, chemical, biological, and natural atmospheric emissions.
The diagram shows a simplified decay scheme of 60Co and 60mCo. The main β-decay transitions are shown. The probability for population of the middle energy level of 2.1 MeV by β-decay is only 0.0022%, with a β-energy of 0.67 MeV. Transitions between the three levels generate six different gamma-ray frequencies. In the diagram the two important ones are marked. Internal conversion is not significant. The half-value and 1/10th value layer thickness for shielding against this isotope's radiations has been determined for different materials:
== Spikes to Stability: Trelagliptin Minimizes Glycemic Variability == Trelagliptin, a once-weekly DPP-4 inhibitor, helps manage glycemic variability (GV) in type 2 diabetes. It works by prolonging the activity of incretins (GLP-1 and GIP), which enhances insulin secretion and suppresses glucagon release in a glucose-dependent manner. This action helps reduce [[[postprandial hyperglycemia]] and smooth out daily blood glucose fluctuations. Continuous glucose monitoring shows improved glycemic stability with lower glucose variability. Trelagliptin also lowers the risk of hypoglycemia due to its glucose-dependent effects. By reducing GV, it helps prevent damage to blood vessels. This ultimately lowers the risk of cardiovascular complications in diabetic patients.
Sources: en.wikipedia.org
=== Global burden === Foodborne illness is a major, and often under-recognized, public-health problem worldwide. The World Health Organization (WHO) estimates that unsafe food causes about 600 million illnesses and 420,000 deaths annually, with children under five disproportionately affected (about 30% of deaths), reflecting persistent shortfalls in water, sanitation, hygiene, and food safety capacity in some regions. In higher-income settings, the burden is also substantial, for example the U.S. Centers for Disease Control and Prevention (CDC) estimates 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths in the United States each year due to foodborne disease. Beyond health impacts, the economic toll is significant. The World Bank has estimated $95.2 billion in annual productivity losses and $15 billion in treatment costs from foodborne diseases in low and middle income countries, underscoring the development implications of inadequate food safety systems. Methodologically, global estimates combine surveillance, outbreak investigations, and modelling such as research about global burden of disease on enteric infections. Overall, diarrheal pathogens such as Norovirus, Campylobacter, Salmonella, invasive Salmonella, and parasitic infections account for the bulk of morbidity and mortality
He provided the voice of the narrator for Disney World's The Hall of Presidents when Obama was added to the exhibit, and when The Hall of Presidents re-opened on July 4, 2009, at Walt Disney World Resort in Orlando, Florida. On day four of the 2016 Democratic National Convention, Freeman provided the voiceover for the video introduction of Democratic presidential candidate Hillary Clinton. On September 19, 2017, Freeman appeared in a video by the Committee to Investigate Russia group, in which he declared "we [United States] are at war" and accusing Russia of "launching cyber attacks and spreading false information". Freeman also endorsed his friend Bill Luckett, who unsuccessfully ran for Governor of Mississippi in 2011. In June 2021, he and Linda Keena, a professor at the University of Mississippi, donated $1 million to the university, establishing the Center for Evidence-Based Policing and Reform.
=== Co-attraction === Co-attraction between collectively migrating cells is the process by which cells of the same type secrete chemo-attractant (e.g. C3a in neural crest cells), that stimulates other cells in the group that have the receptors to that chemo-attractant. Cells sense the secreted substrate and respond to the stimulation by moving towards each other's and maintain high cell density.
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.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。