Everything below concerns ACTH fragment. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
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.
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.
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Gordon R. Ward, writing in the correspondence columns of the British Medical Journal, proposed the use of blood plasma as a substitute for whole blood and for transfusion purposes as early as 1918. At the onset of World War II, liquid plasma was used in Britain. A large project, known as "Blood for Britain", began in August 1940 to collect blood in New York City hospitals for the export of plasma to Britain. Following heavy casualties in the Battle of Dunkirk, the Blood Transfusion Association in New York City originated the campaign that was enlarged to the whole US by the Red Cross, and was called the National Blood Programme. At the time, American physician Edwin Cohn pioneered the process of blood fractionation. He worked out the techniques for isolating the serum albumin fraction of blood plasma, which is essential for maintaining the osmotic pressure in the blood vessels, preventing their collapse. A freeze-dried plasma package was developed by the Surgeons General of the Army and Navy, working with the National Research Council, which reduced breakage and made transportation, packaging, and storage much simpler.
Analysis of mitochondrial DNA by German herpetologist Wolfgang Wüster and colleagues in 2005 found the Papuan and nominate subspecies to be very similar genetically; however, their distinct coloration and limited sampling led Wüster to refrain from lumping the subspecies into a single taxon. Raymond Hoser described Oxyuranus scutellatus barringeri from a specimen collected from the Mitchell Plateau, however Wüster declared this a nomen nudum as the author did not explain how it was distinct. Hoser replied that it was distinct on the basis of DNA and distribution, and published it under a different subspecific name—O. scutellatus andrewwilsoni—in 2009, reporting it had a more rounded head and rougher neck scales than other subspecies of coastal taipan, and lacked a lighter colour on the snout. Kinghorn gave it the name "giant brown snake" in 1930, before Thomson introduced the term taipan in 1933. It is commonly called the coastal taipan, common taipan, or simply taipan. The New Guinea subspecies is known as the Papuan taipan. Local names in New Guinea include dirioro by the people of Parama village near the Fly River, and gobari near the Vailala River.
=== Fourth week (14–18 March) === On 14 March, the Taliban-run Afghan Ministry of Defense said that Taliban forces had captured a Pakistani border outpost, killing 14 soldiers and injuring 11 others. The ministry also added that they destroyed an armored tank and a military vehicle of Pakistani forces. However, Pakistani officials denied allegations made by Afghan Ministry of Defense, terming them false, fabricated and aimed at misleading the Afghan public. According to Pakistani officials, the damages and losses suffered by the Afghan Taliban and the Pakistani Taliban were being regularly documented, with related video and photographic evidence shared with the media. Elsewhere, Pakistani security forces killed six Pakistani Taliban militants in Lakki Marwat. Later that day, Pakistani officials stated that the Pakistan Air Force had carried out airstrikes on five military bases in Kandahar, including the General Directorate of Intelligence (GDI), Haibatullah Akhundzada's special forces unit, the border command, a tunnel, and a Taliban technical equipment warehouse. Pakistani officials added that the targeted military sites had been destroyed and released videos and images of the strikes in Kandahar. Locals in Kandahar told an Agence France-Presse journalist that military aircraft had flown over a mountain housing a military facility before an explosion was heard. Afghan locals sources state that Pakistani airstrikes struck a Taliban special forces facility linked to Hibatullah Akhundzada, as well as an ammunition depot and a border command center in Kandahar Province.
=== Books === Boitano, Scott; Brooks, Heddwen L.; Barman, Susan M.; Barrett, Kim E. (2016). Ganong's Review of Medical Physiology. McGraw-Hill Education. ISBN 978-0-07-182510-8. Susan Standring, ed. (2008). Gray's anatomy: the anatomical basis of clinical practice (40th ed.). London: Churchill Livingstone. ISBN 978-0-8089-2371-8. Cole, Laurence A.; Kramer, Peter R. (2016). Human Physiology, Biochemistry and Basic Medicine. Amsterdam: Academic Press. ISBN 978-0-12-803699-0.
Sources: en.wikipedia.org
Mark Stoyer, a nuclear chemist at the LLNL, later recalled, "We had intended to propose that name from Livermore, and things kind of got proposed at the same time from multiple places. I don't know if we can claim that we actually proposed the name, but we had intended it." In internal discussions, IUPAC asked the JINR if they wanted the element to be spelled "oganeson" to match the Russian spelling more closely. Oganessian and the JINR refused this offer, citing the Soviet-era practice of transliterating names into the Latin alphabet under the rules of the French language ("Oganessian" is such a transliteration) and arguing that "oganesson" would be easier to link to the person. In June 2016, IUPAC announced that the discoverers planned to give the element the name oganesson (symbol: Og). The name became official on 28 November 2016. In 2017, Oganessian commented on the naming:
== Scientific research == Amarasate capsules have been clinical tested and demonstrated to reduce hunger and emptiness, to decrease food intake and to increase blood concentrations of appetite suppressing gut peptide hormones CCK, GLP-1 and PYY. Amarasate was developed on the concept that by activating bitter taste receptors (TAS2Rs), in the gastrointestinal tract, it would stimulate the release of these gut-derived hormones and potentially lead to weight loss. Clinical and laboratory research indicates that Amarasate increases GLP-1 and CCK to six times baseline levels, approximately twice the normal post-meal hormone response, within one hour of ingestion. This response mimics the body's natural satiety mechanisms without the use of external GLP-1 agonists. Three small clinical trials have been published, in normal humans:
'Weird.'" Olsen saw Dogtooth's substance as "part enigma, part allegory and even part sci-fi in its creation of a completely alternate reality." Ebert found a "message" in the film, which he put as: "God help children whose parents insanely demand unquestioning obedience to their deranged standards.... [S]ome have even described the film as a comedy. I wasn't laughing." For Bradshaw, the film investigates "the essential strangeness of something society insists is the benchmark of normality: the family, a walled city state with its own autocratic rule and untellable secrets." Harkness noted the "absolute mockery the situation makes of the perfect family ideal", where "Lanthimos isn't interested in making specific political or social points and he refuses to offer any clarifying backstory", and found Dogtooth's oddness "as organic and playful as its impact is incisor sharp." In a 2012 interview, filmmaker David Lynch called Dogtooth "a fantastic comedy". In July 2025, it ranked number 84 on Rolling Stone's list of "The 100 Best Movies of the 21st Century." Also that month, it was one of the films voted for the "Readers' Choice" edition of The New York Times' list of "The 100 Best Movies of the 21st Century," finishing at number 301.
Sources: en.wikipedia.org
=== Reductive half === The action of GR proceeds through two distinct half reactions, a reductive half mechanism followed by an oxidative half. In the first half, NADPH reduces FAD present in GSR to produce a transient FADH− anion. This anion then quickly breaks a disulfide bond of Cys58 - Cys63, forming a short lived covalent bond a stable charge-transfer complex between the flavin and Cys63. The now oxidized NADP+ is released and is subsequently replaced by a new molecule of NADPH. This is the end of the so-called reductive half of the mechanism.
The reaction of endo-Tropacocaine [19145-60-9] (1) with 2,2,2-Trichloroethyl chloroformate (Troc group) [17341-93-4] (2) gave the urethane PC11463908 (3). Reduction with zinc in acetic acid afforded the nortropane, PC11458897 (4). Protection of the secondary amine with Boc anhydride gave PC66624775 (5). Saponification of the ester in potassium hydroxide gave PC11160507 (6). Mitsunobu reaction with 7-hydroxy-3-methoxy-chromen-2-one (Methoxy-Umbelliferon) [68287-05-8] (7) occurred with inversion of stereochemistry from the endo to the exo position, PC89405050 (8). Acid hydrolysis of the Boc protecting group completed the synthesis of pudafensine (9).
Researchers focused on the following symptoms: hair loss, memory loss, dry eyes and/or blurred vision, numbness or tingling in the extremities, chronic fatigue, joint pain, rashes, breast pain, food intolerance, flu-like symptoms, and difficulty breathing. The same authors also published a study on the impact of breast implant removal on breathing difficulties and found a statistically significant improvement in well-established objective measures of pulmonary function following explant surgery.
== Types == Types include those acting directly as membrane-bound receptors (Receptor protein serine/threonine kinase) and intracellular kinases participating in Signal transduction. Of the latter, types include:
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.