If you have been reading about ACTH(4-10) and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-05-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
| Property | Value | Notes |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
H2CO3 ⇌ H+ + HCO−3 ⇌ 2 H+ + CO2−3 allow the prediction of concentrations of each dissolved inorganic carbon species in solution, from the added concentration of HCO−3 (which constitutes more than 90% of Bjerrum plot species from pH 7 to pH 8 at 25 °C in fresh water). Addition of HCO−3 will increase CO2−3 concentration at any pH. Rearranging the equations given above, we can see that [Ca2+] = Ksp/[CO2−3], and [CO2−3] = Ka2 [HCO−3]/[H+]. Therefore, when HCO−3 concentration is known, the maximum concentration of Ca2+ ions before scaling through CaCO3 precipitation can be predicted from the formula:
==== Fistula formation and gallstone ileus ==== The inflammation of cholecystitis can lead to adhesions between the gallbladder and other parts of the gastrointestinal tract, most commonly the duodenum. These adhesions can lead to the formation of direct connections between the gallbladder and gastrointestinal tract, called fistulas. With these direct connections, gallstones can pass from the gallbladder to the intestines. Gallstones can get trapped in the gastrointestinal tract, most commonly at the connection between the small and large intestines (ileocecal valve). When a gallstone gets trapped, it can lead to an intestinal obstruction, called gallstone ileus, leading to abdominal pain, vomiting, constipation, and abdominal distension.
The first example of the practical application of this FAB was the elucidation of the amino acid sequence of the oligopeptide efrapeptin D. This contained a variety of very unusual amino acid residues. The sequence was shown to be: N-acetyl-L-pip-AIB-L-pip-AIB-AIB-L-leu-beta-ala-gly-AIB-AIB-L-pip-AIB-gly-L-leu-L-iva-AIB-X. PIP = pipecolic acid, AIB = alpha-amino-isobutyric acid, leu = leucine, iva = isovaline, gly = glycine. This is a potent inhibitor of mitochondrial ATPase activity. Another application of FAB includes its original use for the analysis of condensed-phase samples. FAB can be use for measurements of the molecular weight of samples below 5000 Da, as well as their structural characteristics. FAB can be paired with various mass spectrometers for data analysis, such as with a quadrupole mass analyzer, liquid chromatography–mass spectrometry, and more.
==== Newsletter ==== The IIR produces an electronic monthly newsletter that features news and updates on the refrigeration sector: regulation, events, economic data, monitoring, technological progress, etc. It provides a detailed overview of the general developments within the sector worldwide and as acts a regular information tool for readers.
Almost any kind of fish is used, but the most common variant uses rabbitfish (locally known as danggit). Cuttlefish and squid may also be dried this way The amount of drying can vary. In the labtingaw variant, the drying period only lasts a few hours, allowing the fish to retain some moisture and texture. In the lamayo variant, the fish is not dried at all, but simply marinated in vinegar, garlic and spices. Dried squid Eja kika : A Yoruba smoked dried fish. Smoking can also be combined with sun-drying. Eja kika involves several types of fish; the techniques are used not only to preserve fish for longer shelf life, but to enhance the flavor for greater effect in for dishes prepared with the fish. Fesikh is a traditional Egyptian fish dish consisting of fermented salted and dried gray mullet, of the mugil family, a saltwater fish that lives in both the Mediterranean and the Red Seas. The traditional process of preparing it is to dry the fish in the sun before preserving it in salt. Gwamegi is a Korean half-dried Pacific herring or Pacific saury made during winter. It is mostly eaten in the region of North Gyeongsang Province such as Pohang, Uljin, and Yeongdeok, where a large amount of the fish are harvested. Guryongpo Harbor in Pohang is the most famous. Fresh herring or saury is frozen at -10 degrees Celsius and is placed outdoors in December to repeat freezing at night and thawing in the day. The process continues until the water content of the fish drops to approximately 40%.
Sources: en.wikipedia.org
=== Final Cuban offensive === Although the SADF and UNITA counteroffensive had been checked, FAPLA remained heavily strained and more dependent than before on its Cuban allies and Soviet materiel. This gave dos Santos an incentive to ease the military dilemma with negotiations and he reopened the possibility of reaching a new ceasefire and disengagement agreement with South Africa. As early as January 1987, Chester Crocker had responded to positive signals from Luanda, especially when President Denis Sassou Nguesso of the People's Republic of the Congo offered to mediate peace talks between the rival states. Yet preliminary discussions in Brazzaville throughout late 1987 and early 1988 remained stymied by the Angolan government's refusal to compromise on the timetable for a proposed Cuban withdrawal. The Cuban government had not been consulted on the Brazzaville talks in advance and resented what it perceived as a discourtesy on the part of dos Santos. This factor had the effect of persuading Castro to make an authoritative bid to join the Angolan-US peace talks. He was determined that Cuba no longer be excluded from negotiations concerning its own military, and the results of any future settlement on the withdrawal process leave Cuba's image untarnished.
Antigen-presenting cell Technologies which may allow rapid vaccine deployment in response to a novel pathogen include the use of virus-like particles or protein nanoparticles. Inverse vaccines are vaccines that train the immune system to not respond to certain substances. While most vaccines are created using inactivated or attenuated compounds from microorganisms, synthetic vaccines are composed mainly or wholly of synthetic peptides, carbohydrates, or antigens.
== Use == So far, biomass-based production of industrial microalgae has been widely applied in the fields from food and feed to high-value chemicals for pharmaceutical and ecological applications. Although the commercial cultivation of microalgae became increasingly popular, only algal biomass is processed to current products, while huge volumes of algae-free media are unexploited in flow through cultures and after biomass harvesting of batch cultures. Medium recycling to save culturing costs faces the big risk of growth inhibition. High volumes of spent media give rise to environmental pollution and cost of water and nutrition supply in cultivation when the media are discarded directly to the environment. Therefore the application of recycling methods motivated by the simultaneous generation of high value products from spent medium bears potential in commercial and environmental perspectives.
== Expansions and sequels == Half-Life was followed by an expansion pack, Opposing Force, on November 1, 1999, developed by Gearbox Software. Players control Hazardous Environment Combat Unit (HECU) Corporal Adrian Shephard, who fights a new group of aliens, Race X, and Black Ops units after being split from his team. Gearbox developed a second expansion pack, Blue Shift, in which players control Barney Calhoun, a security guard at Black Mesa, as he attempts to escape the facility. It was developed as a bonus campaign for the Dreamcast port of Half-Life, but was released for Windows on June 12, 2001, after the port was canceled. Gearbox created a cooperative multiplayer expansion pack, Decay, exclusively for the PlayStation 2 port of Half-Life which is played through the perspectives of Gina Cross and Colette Green, two Black Mesa scientists. Half-Life 2 was released in 2004. The player controls Freeman 20 years after the Black Mesa incident in the dystopian City 17, where he joins a rebellion against an alien regime. It was followed by the episodic sequels Half-Life 2: Episode One (2006) and Half-Life 2: Episode Two (2007). After cancelling several other Half-Life projects, Valve released Half-Life: Alyx in 2020.
==== Endocrine actions ==== Valproic acid has been found to be an antagonist of the androgen and progesterone receptors, and hence as a nonsteroidal antiandrogen and antiprogestogen, at concentrations much lower than therapeutic serum levels. In addition, the drug has been identified as a potent aromatase inhibitor, and suppresses estrogen concentrations. These actions are likely to be involved in the reproductive endocrine disturbances seen with valproic acid treatment. Valproic acid has been found to directly stimulate androgen biosynthesis in the gonads via inhibition of histone deacetylases and has been associated with hyperandrogenism in women and increased 4-androstenedione levels in men. High rates of polycystic ovary syndrome and menstrual disorders have also been observed in women treated with valproic acid.
Sources: en.wikipedia.org
A nonstop mutation, also called a stop-loss variant, is a point mutation that occurs within a stop codon. Nonstop mutations cause the continued translation of an mRNA strand into what should be an untranslated region. Most polypeptides resulting from a gene with a nonstop mutation lose their function due to their extreme length and the impact on normal folding. Nonstop mutations differ from nonsense mutations in that they do not create a stop codon but, instead, delete one. Nonstop mutations also differ from missense mutations, which are point mutations where a single nucleotide is changed to cause replacement by a different amino acid. Nonstop mutations have been linked with many inherited diseases including endocrine disorders, eye disease, and neurodevelopmental disorders.
=== 1960s === 1964: opens first subsidiary, in France 1967: introduces the Super-Q water purification system 1967: establishes German subsidiary 1968: establishes Japanese subsidiary 1968: introduces Pellicon cassette product, for purifying biotherapeutics
== Hormone-behavior interactions == At the neurological level, behavior can be inferred based on hormone concentration, which in turn are influenced by hormone-release patterns; the numbers and locations of hormone receptors; and the efficiency of hormone receptors for those involved in gene transcription. Hormone concentration does not incite behavior, as that would undermine other external stimuli; however, it influences the system by increasing the probability of a certain event to occur. Not only can hormones influence behavior, but also behavior and the environment can influence hormone concentration. Thus, a feedback loop is formed, meaning behavior can affect hormone concentration, which in turn can affect behavior, which in turn can affect hormone concentration, and so on. For example, hormone-behavior feedback loops are essential in providing constancy to episodic hormone secretion, as the behaviors affected by episodically secreted hormones directly prevent the continuous release of said hormones. Three broad stages of reasoning may be used to determine if a specific hormone-behavior interaction is present within a system:
In a TV interview in February 2001, Bush's new attorney general, John Ashcroft, said about the war on drugs, "I want to renew it. I want to refresh it, relaunch it if you will." In 2001, after 9/11 and the Patriot Act, the DEA began highlighting the tie between drug trafficking and international terrorism, gaining the agency expanded funding to increase its global presence.
== Natural occurrence of piperidine and derivatives == Piperidine itself has been obtained from black pepper, from Psilocaulon absimile (Aizoaceae), and in Petrosimonia monandra. The piperidine structural motif is present in numerous natural alkaloids. These include piperine, which gives black pepper its spicy taste. This gave the compound its name. Other examples are the fire ant toxin solenopsin, the nicotine analog anabasine of tree tobacco (Nicotiana glauca), lobeline of Indian tobacco, and the toxic alkaloid coniine from poison hemlock, which was used to put Socrates to death.
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.