Semax is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-04-14. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
=== Native chemical ligation === The most practical and robust method for the chemoselective reaction of unprotected peptides is native chemical ligation. The original chemical ligation methods involved the formation of a non-native bond at the ligation site. Subsequently, native chemical ligation was developed. In native chemical ligation, an unprotected peptide thioester reacts with the N-terminal cysteine of a second peptide to give a ligation product in which a native peptide bond joins the two peptide segments In this method, an initial thioester-linked ligation product intermediate rearranges to form an amide bond. Native chemical ligation overcomes the limitations of the classical synthetic organic chemistry approach to the total synthesis of proteins, and enabled the routine total or semi- synthesis of protein molecules. Native chemical ligation relies on the presence of a cysteine residue at the ligation site. Methods using removable auxiliary groups can in some instances extend the use of native chemical ligation to non-cysteine residues, as can the use of desulfurization subsequent to the ligation (e.g. converting a Cys to an Ala).
=== Brand names === As of October 2017, pregabalin is marketed under many brand names: Algerika, Alivax, Alyse, Alzain, Andogablin, Aprion, Averopreg, Axual, Balifibro, Brieka, Clasica, Convugabalin, Dapapalin, Dismedox, Dolgenal, Dolica, Dragonor, Ecubalin, Epica, Epiron, Gaba-P, Gabanext, Gabarol, Gabica, Gablin, Gablovac, Gabrika, Gavin, Gialtyn, Glonervya, Helimon, Hexgabalin, Irenypathic, Kabian, Kemirica, Kineptia, Lecaent, Lingabat, Linprel, Lyribastad, Lyric, Lyrica, Lyrineur, Lyrolin, Lyzalon, Martesia, Maxgalin, Mystika, Neuragabalin, Neugaba, Neurega, Neurica, Neuristan, Neurolin, Neurovan, Neurum, Newrica, Nuramed, Paden, Pagadin, Pagamax, Painica, Pevesca, PG, Plenica, Pragiola, Prebalin, Prebanal, Prebel, Prebictal, Prebien, Prefaxil, Pregaba, Pregabalin, Pregabalina, Pregabaline, Prégabaline, Pregabalinum, Pregabateg, Pregaben, Pregabid, Pregabin, Pregacent, Pregadel, Pregagamma, Pregalex, Pregalin, Pregalodos, Pregamid, Pregan, Preganerve, Pregastar, Pregatrend, Pregavalex, Pregdin Apex, Pregeb, Pregobin, Prejunate, Prelin, Preludyo, Prelyx, Premilin, Preneurolin, Prestat, Pretor, Priga, Provelyn, Regapen, Resenz, Rewisca, Serigabtin, Symra, Vronogabic, Xablin, and Xil.
== Formation of sugar-carbamino == The sugar-carbamino is formed through a C-glycosidic linkage with the amino acid side chain via various linkers. The synthesis involves introducing annulation to appropriate amino acid residues to rigidify glycopeptides, followed by Diels-Alder cycloadditions to fuse cyclic α- and β-amino acids to the sugar moiety. This also involves the preparation of fused bicyclic C-glycosyl α-amino acid 4, which is confirmed through 2D NMR experiments, particularly NOESY. The approach to conformationally constrained (annulated)-C-glycosyl α- and β-amino acids is based upon the Diels-Alder reaction of pyranose dienes with α- and β-nitro acrylic esters.
=== Developmental stage === Adolescence is the period of greatest risk both for first use of an addictive drug and for the transition to disordered use. The prefrontal cortex, which supports planning, inhibitory control and the weighing of long-term consequences, develops more slowly than the brain's reward circuitry and is not fully mature until the mid-twenties. During this window sensitivity to reward is high while cognitive control is still developing, which contributes to greater risk-taking, including experimentation with drugs. Drug exposure in early adolescence can in turn disturb cortical development and delay prefrontal maturation, and prefrontal dysfunction in adolescents is itself associated with a higher risk of substance use disorder.
Sources: en.wikipedia.org
== International reactions == Canada: Canada's ambassador to the United Nations compared U.S. president Donald Trump's Golden Dome to a protection racket after Trump said America's northern neighbor must either pay $61 billion to join the program or could agree to annexation (in which case inclusion would be free). Ambassador Bob Rae also noted that "threats to sovereign integrity are prohibited" under the Charter of the United Nations. Earlier, Canadian minister of national defence Bill Blair had expressed a willingness for participation in the Golden Dome project. China: On 21 May 2025, Foreign Ministry spokesperson Mao Ning criticized the Golden Dome plan, claiming it "violates the principle of peaceful use of space in the Outer Space Treaty". She called on the US to "give up developing and deploying [a] global anti-missile system", which risked "turning space into a war zone". In a white paper published by the State Council Information Office in November 2025, China criticized the move towards "absolute security" and that it would "pose a serious threat to outer space security". New Zealand: New Zealand defence minister Judith Collins expressed support for the Golden Dome missile system, saying "I don't see it as an attack mechanism. It's a defence mechanism. And if people did not feel they needed to defend themselves, they wouldn't waste the money on it." Trump had earlier noted the space-based system would be "a very big part of our defense and, obviously, of our offense" and capable of striking foreign assets even before they launch.
Key components of natural product synthesis include retrosynthetic analysis, which involves planning synthetic routes by working backward from the target molecule to design the most effective construction pathway. Stereochemical control is crucial to ensure the correct three-dimensional arrangement of atoms, critical for the molecule's functionality. Reaction optimization enhances yield, selectivity, and efficiency, making synthetic steps more practical. Finally, scale-up considerations allow researchers to adapt lab-scale syntheses for larger production, expanding the accessibility of synthesized products. This evolving field continues to fuel advancements in drug development, materials science, and our understanding of the diversity in natural compounds.
Cortisol is a steroid hormone in the glucocorticoid class of hormones and a stress hormone. When used as medication, it is known as hydrocortisone. Cortisol is produced in many animals, mainly by the zona fasciculata of the adrenal cortex in an adrenal gland. In other tissues, it is produced in lower quantities. By a diurnal cycle, cortisol is released and increases in response to stress and a low blood-glucose concentration. It functions to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in energy metabolism. It also decreases bone formation. These stated functions are carried out by cortisol binding to glucocorticoid or mineralocorticoid receptors inside a cell, which then bind to DNA to affect gene expression.
== Syndesmosis == A syndesmosis is a slightly mobile fibrous joint in which bones such as the tibia and fibula are joined together by connective tissue. An example is the distal tibiofibular joint. Injuries to the ankle syndesmosis are commonly known as a "high ankle sprain". Although the syndesmosis is a joint, in the literature the term syndesmotic injury is used to describe injury of the syndesmotic ligaments. It comes from the Greek σύν, syn (meaning "with") and δεσμός, desmos (meaning "a band"). Syndesmosis sprains have received increasing recognition during recent years because of a heightened awareness of the mechanism, symptoms, and signs of injury.
=== Oxidative stress === Oxidative stress causes the accumulation of reactive oxygen species (ROS), resulting in oxidative damage to DNA, proteins involved in cellular repair, and lipids that support the skin barrier. Oxidative stress can hinder the fibroblasts' collagen production, endothelial cell angiogenesis, and keratinocytes' re-epithelialization. The result of oxidative stress is a state of cellular senescence, where cells secrete pro-inflammatory factors and are unable to divide. Senescent cells signal to immune cells, perpetuating a non-resolving wound that can develop into an ulcer.
Sources: en.wikipedia.org
== Epidemiology == The first estimate of US prevalence for autoimmune diseases as a group was published in 1997 by Jacobson, et al. They reported US prevalence to be around 9 million, applying prevalence estimates for 24 diseases to a US population of 279 million. Jacobson's work was updated by Hayter & Cook in 2012. This study used Witebsky's postulates, as revised by Rose & Bona, to extend the list to 81 diseases and estimated overall cumulative US prevalence for the 81 autoimmune diseases at 5.0%, with 3.0% for males and 7.1% for females. In 2025, a study using electronic medical records from over 15 million patients at six large academic medical systems in the United States found a prevalence of 4.6% for autoimmune disease, based on a list of 105 conditions from The Rose and Mackay Textbook of Autoimmune Diseases. The study also found that over 34% of patients with an autoimmune disease had at least one other autoimmune condition, compared to cancer, where 8.1% of patients are diagnosed with a second primary malignancy.
=== Early years (2007–2017) === Thechineseroom's first three projects were two mods for Half-Life 2, named Antlion Soccer and Dear Esther, and a Doom 3 mod, Conscientious Objector. The modding project was backed by the Arts and Humanities Research Council. Of these, Dear Esther became a cult hit. In 2009, Thechineseroom developed Korsakovia, which was a survival horror mod. After Korsakovia, Thechineseroom worked with Robert Briscoe to develop a remake of Dear Esther, this time as a full-fledged video game, distributed through Valve's Steam distribution service. This stand-alone version of the mod received several IGF nominations, such as the Seamus McNally Grand Prize, Excellence in Visual Arts and Audio, and the Nuovo Award. It finally won for Excellence in Visual Art. The remake featured improved graphics, but was based on the same engine as the previous mods, Source. The game was released in early 2012 and reached 50,000 copies sold within one week. In February 2012, Thechineseroom announced that they began development on Amnesia: A Machine for Pigs, a survival horror game and indirect sequel to Amnesia: The Dark Descent. This project was produced by the makers of the original game, Frictional Games. Thechineseroom also began work on their newest game, Everybody's Gone to the Rapture alongside the development of Amnesia: A Machine for Pigs. During that time, on 11 June 2013, they renamed themselves to the Chinese Room, introducing a new logo. The studio team partnered with Santa Monica Studio to produce Everybody's Gone to the Rapture.
Freeze drying, also known as lyophilization or cryodesiccation, is a low-temperature dehydration process that involves freezing the product and lowering pressure, thereby removing the ice by sublimation. This is in contrast to dehydration by most conventional methods that evaporate water using heat. Because of the low temperatures used in processing, the rehydrated product retains many of its original qualities. When solid objects like strawberries are freeze dried the original shape of the product is maintained. If the product to be dried is a liquid, as often seen in pharmaceutical applications, the properties of the final product are optimized by the combination of excipients (i.e., inactive ingredients). Primary applications of freeze drying include biological (e.g., bacteria and yeasts), biomedical (e.g., surgical transplants), food processing (e.g., coffee), and food preservation.
As a sign of the expanding commercial ties between the two regions (and Han and Tibetan peoples in particular), a special exhibition was held in Chengdu, so that Sichuanese may see and come into contact with Xikang products. In order to levy taxes from the region, Liu also established a Finance Ministry. Historians and analysts have debated over the effectiveness of these measures. Yang Zhonghua, writing in 1941, praised them as a relatively proactive policy; however, it has been argued by Xie Benzao that Liu's plans, though ambitious on paper, were limited by the realities of war and mostly for the purpose of resource extraction. Another road-building project of Liu Wenhui, constructed in the late 1920s from Yazhou to Chengdu, was known by locals mainly for the ruthlessness of its methods. Despite these projects, Xikang was mostly seen as a rear location distant from the conflicts in Sichuan. Liu encouraged students from Sichuan to take part in "border construction" in Xikang. In September 1929, he set up a newsletter, Bianzheng (邊政), dedicated to frontier administration. The issues of the Bianzheng promoted Sun Yat-sen's Three Principles and advertised Xikang as an attractive region for Chinese settlement, teeming with resources but nonetheless coveted by British imperialists. Propaganda plays published in the newsletter, which can be seen as the official policy of Liu Wenhui's government, exhorted youths to settle and develop the Xikang frontier, despite hardships, and thwart the imperialist plans of Tibet and Britain.
=== American Cancer Society === Inhorn's ongoing interest in cervical cancer was the reason that he joined the American Cancer Society, Wisconsin Division, in 1967. He was Chair of the State Cancer Prevention Study II, and in 1986, he headed a demonstration project with a number of Wisconsin hospitals to determine the acceptance of offering low-cost mammography as a screening test for breast cancer. Inhorn served as President of the Wisconsin Division from 1970 to 1972, continuing on the board until 2010. He also served on the national American Cancer Society Board from 1982 to 1990.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。