This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-09. Anything still debated is marked as such rather than presented as settled.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
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 | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
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.
Dom Pothier died at the old priory of Conques, Belgium in 1923; the Bishop of Luxembourg and six prelates attended his funeral at Clervaux abbey, Luxembourg (his remains later were transferred to Saint-Wandrille in 1962). The exiled community of St Wandrille's Abbey, under Dom Pothier as Abbot, founded in 1912 a new priory in Canada, Saint Benedict Abbey, Quebec, which later became independent within the Solesmes Congregation.
=== Sports medicine, concussion, chronic traumatic encephalopathy (CTE), and hyperbaric oxygen therapy (HBO) === Maroon served as the team neurosurgeon for the Pittsburgh Steelers for 40 years, becoming one of the longest-tenured team neurosurgeons in the NFL. Although now retired from active surgical duties, he continues to serve as a medical consultant to the Steelers. He also served as medical director for WWE from 2009 to 2023 and remains a consultant to the organization. He is a past president of the Congress of Neurological Surgeons. Together with neuropsychologist Mark Lovell, Maroon developed ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), a tool to assess the presence and severity of concussion symptoms. It has become the standard assessment for sports-related concussions, with over 25 million tests administered worldwide. Maroon is interested in the prevention and treatment of concussions, specifically in football. In 2006, he joined the National Football League's Mild Traumatic Brain Injury Committee, which, in 2007, was renamed the Head, Neck, and Spine Committee. He has been consulted as an expert by American media on this subject. Based on his research into the predictors and scope of chronic traumatic encephalopathy (CTE), he has suggested a more cautious approach to characterizing the condition as an epidemic. He claims there is reason to be skeptical of the reported widespread incidence of CTE.
The Farmer's Market was launched in 2006 and moved onto Tor in 2010. In 2012, it was closed and several operators and users were arrested as a result of Operation Adam Bomb, a two-year investigation led by the U.S. Drug Enforcement Administration. It has been considered a "proto-Silk Road" but the use of payment services such as PayPal and Western Union allowed law enforcement to trace payments and it was subsequently shut down by the FBI in 2012.
== Potential applications == A wide variety of potential applications have been envisaged. Since magnetic nanoparticles are expensive to produce, there is interest in their recycling or for highly specialized applications. The potential and versatility of magnetic chemistry arises from the fast and easy separation of the magnetic nanoparticles, eliminating tedious and costly separation processes usually applied in chemistry. Furthermore, the magnetic nanoparticles can be guided via a magnetic field to the desired location which could, for example, enable pinpoint precision in fighting cancer.
==== Receptor and ion channel targets ==== Caffeine is an antagonist of adenosine A2A receptors, and knockout mouse studies have specifically implicated antagonism of the A2A receptor as responsible for the wakefulness-promoting effects of caffeine. Antagonism of A2A receptors in the ventrolateral preoptic area (VLPO) reduces inhibitory GABA neurotransmission to the tuberomammillary nucleus, a histaminergic projection nucleus that activation-dependently promotes arousal. This disinhibition of the tuberomammillary nucleus is the downstream mechanism by which caffeine produces wakefulness-promoting effects. Caffeine is an antagonist of all four adenosine receptor subtypes (A1, A2A, A2B, and A3), although with varying potencies. The affinity (KD) values of caffeine for the human adenosine receptors are 12 μM at A1, 2.4 μM at A2A, 13 μM at A2B, and 80 μM at A3. Antagonism of adenosine receptors by caffeine also stimulates the medullary vagal, vasomotor, and respiratory centers, which increases respiratory rate, reduces heart rate, and constricts blood vessels. Adenosine receptor antagonism also promotes neurotransmitter release (e.g., monoamines and acetylcholine), which endows caffeine with its stimulant effects; adenosine acts as an inhibitory neurotransmitter that suppresses activity in the central nervous system. Heart palpitations are caused by blockade of the A1 receptor. Because caffeine is both water- and lipid-soluble, it readily crosses the blood–brain barrier that separates the bloodstream from the interior of the brain.
Sources: en.wikipedia.org
In addition, the bioavailability of (E)-doxepin was about 2-fold lower in extensive relative to poor CYP2D6 metabolizers, indicating a significant role of CYP2D6 in the first-pass metabolism of (E)-doxepin. The clearance of (E)-doxepin in CYP2C9 slow metabolizers was also significantly reduced at 238 L/hour. CYP2C19 was involved in the metabolism of (Z)-doxepin, with clearance rates of 191 L/hour in CYP2C19 extensive metabolizers and 73 L/hour in poor metabolizers (~2.5-fold difference). Area-under-the-curve (0–48 hour) levels of nordoxepin were dependent on the genotype of CYP2D6 with median values of 1.28, 1.35, and 5.28 nM•L/hour in CYP2D6 extensive, intermediate, and poor metabolizers, respectively (~4-fold difference between extensive and poor). Taken together, doxepin metabolism appears to be highly stereoselective, and CYP2D6 genotype has a major influence on the pharmacokinetics of (E)-doxepin. Moreover, CYP2D6 poor metabolizers, as well as patients taking potent CYP2D6 inhibitors (which can potentially convert a CYP2D6 extensive metabolizer into a poor metabolizer), may be at an increased risk for adverse effects of doxepin due to their slower clearance of the drug. Another study assessed doxepin and nordoxepin metabolism in CYP2D6 ultra-rapid, extensive, and poor metabolizers following a single 75 mg oral dose. They found up to more than 10-fold variation in total exposure to doxepin and nordoxepin between the different groups.
Laurence Fox is charged with a sexual offence after allegedly sharing an intimate image of television star Narinder Kaur without her consent. 26 March – Chancellor Rachel Reeves will deliver the March 2025 United Kingdom spring statement to the House of Commons. 28 March – Matthew Doyle announces he is stepping down as Downing Street Director of Communications. Sinn Féin councillor Cathal King is suspended for two months from Newry, Mourne and Down District Council by the Northern Ireland Local Government Commission for Standards for being drunk in charge of a car. 28–29 March – 2025 Alba Party leadership election 29 March – BBC News reports that Amanda Spielman, who was chief inspector of Ofsted at the time Ruth Perry committed suicide following a poor Ofsted assessment, has been nominated for a peerage by Conservative leader Kemi Badenoch. Three Bolsover District Councillors resign from the Labour Party in protest at Keir Starmer's leadership, and will sit as independents. 30 March – Downing Street sources tell the BBC the UK would not hesitate to retaliate against US tariffs if required. Talks are held between the prime minister and US president, which are subsequently described as "constructive".
SO2 + Cl2 → SO2Cl2 Sulfur dioxide is the oxidising agent in the Claus process, which is conducted on a large scale in oil refineries. Here, sulfur dioxide is reduced by hydrogen sulfide to give elemental sulfur:
According to the Federal Emergency Management Agency (FEMA), Waffle House is one of the top four corporations, along with Walmart, The Home Depot, and Lowe's, for disaster response. Waffle House has an extensive disaster management plan with on-site and portable generators, and positions food and ice ahead of severe weather events such as a hurricane. This helps mitigate the effects of a storm on the power grid and the supply chains. The company prepares "jump teams" of recovery staff and supplies, brought in from outside disaster-affected areas, so that local staff can focus on helping their own homes and families. The ability of a Waffle House to remain open after a severe storm, possibly with a limited menu, is used by FEMA as a measure of disaster recovery known as the Waffle House Index.
Sources: en.wikipedia.org
=== Side effects === Side effects with anabolic agents are very serious and are not to be ignored. Side effects include: acne, blood clots, aggressiveness, hallucinations, mania, stomach pain, headaches, dizziness, high blood pressure, testicular or scrotal pain, premature male baldness, hear attack, stroke, and liver or kidney failure.
The enlisted corps ranks were: private, noncommissioned officers, and officers. The private classes were: jōtō-hei or upper soldier, ittō-sotsu or first-class soldier, and nitō-sotsu or second-class soldier. The noncommissioned officer class ranks were: gochō or corporal, gunsō or sergeant, sōchō or sergeant major, and tokumu-sōchō or special sergeant major.
Finally, the two pieces are combined by pigC and its cofactor adenosine triphosphate (ATP) in a dehydration reaction which establishes a conjugated system across all three rings and completes the synthesis of prodigiosin.
The mechanism for this form of recombination and repair have been linked to the nucleotide excision repair (NER) pathway playing a role in recognizing and repairing triplex structures. Multiple investigations suggests that the xeroderma pigmentosum group A (XPA) and replication protein A (RPA), which are NER factors, are able to bind specifically as a complex to cross-linked triplex structures. It is known that this mechanism alongside others play a role in recognizing and repairing triplex structures. The in vivo delivery of TFOs has been a major barrier in using TFOs for gene modification. One study on in vivo targeting of hematopoietic stem cells proposed a novel technique of conjugating PNA molecules with cell penetrating peptide (CPPs) alongside poly(lactic-co-glycolic acid) (PLGA) nanoparticles to enable 6 bp modifications in the CCR5 gene. The editing of the CCR5 gene has been linked to HIV-1 resistance. CPPs are proteins that are able to carry "cargo" such as small proteins or molecules successfully into cells. The PGLAs are biodegradable material that encapsulate PNA molecules as nanoparticles for site specific genome modifications. The study found that the PNA-DNA PGLA nanoparticles were able to effectively edit the hematopoietic stem cells with lower toxicity and virus-free and the conjugation with CPP offered direct targeting of the genes for site-specific mutagenesis in the stem cells.
=== Generic names === Anastrozole is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and JANTooltip Japanese Accepted Name.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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。