Semax raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-25 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
==== 17 April 2012 massacre ==== Dismembered remains of 14 men were found in several plastic bags inside a Chrysler Voyager in the border city of Nuevo Laredo, Tamaulipas, on 17 April 2012. All of those killed were between the ages of 30 and 35. Officials stated that they found a "message signed by a criminal group", but they did not release the content of the note, nor if those killed were members of Los Zetas or of the Gulf Cartel. CNN en Español stated that the message left behind by the criminal group said that they were going to "clean up Nuevo Laredo" by killing Zeta members. The Monitor newspaper, however, said that a source outside of law enforcement but with direct knowledge of the attacks stated the 14 bodies belonged to members of Los Zetas who had been killed by the CJNG, now a branch of the Sinaloa Cartel. Following the attacks, the Sinaloa cartel's kingpin, Joaquín Guzmán Loera—better known as El Chapo Guzmán—sent a message to Los Zetas that they will fight for the control of the Nuevo Laredo plaza. The message read the following:
== Drug-drug interactions == As of 2004 it was known that oxandrolone greatly increases warfarin's blood-thinning effect, sometimes dangerously so. In April 2004, Savient Pharmaceuticals published a safety alert through the FDA warning healthcare professionals of this. Oxandrolone also inhibits the metabolism of oral hypoglycemic agents. It may worsen edema when taken alongside corticosteroids or adrenocorticotropic hormone.
α-Haloesters are generally thought of as highly reactive and consequently toxic intermediates in organic synthesis. Nevertheless, mammals, including humans, cats, and rats, appear to biosynthesise traces of an α-bromoester, 2-octyl 4-bromo-3-oxobutanoate, which is found in their cerebrospinal fluid and appears to play a yet unclarified role in inducing REM sleep. Neutrophil myeloperoxidase can use H2O2 and Br− to brominate deoxycytidine, which could result in DNA mutations. Marine organisms are the main source of organobromine compounds, and it is in these organisms that bromine is more firmly shown to be essential. More than 1600 such organobromine compounds were identified by 1999. The most abundant is methyl bromide (CH3Br), of which an estimated 56,000 tonnes is produced by marine algae each year. The essential oil of the Hawaiian alga Asparagopsis taxiformis consists of 80% bromoform. Most of such organobromine compounds in the sea are made by the action of a unique algal enzyme, vanadium bromoperoxidase. The bromide anion is not very toxic: a normal daily intake is 2 to 8 milligrams. However, high levels of bromide chronically impair the membrane of neurons, which progressively impairs neuronal transmission, leading to toxicity, known as bromism. Bromide has an elimination half-life of 9 to 12 days, which can lead to excessive accumulation. Doses of 0.5 to 1 gram per day of bromide can lead to bromism. Historically, the therapeutic dose of bromide is about 3 to 5 grams of bromide, thus explaining why chronic toxicity (bromism) was once so common.
The research results (see table) indicate that about 1 in 5 people have a slow transit (type 1 and 2 stools), while 1 in 12 has an accelerated transit (type 5 and 6 stools). Moreover, the nature of the stool is affected by age, sex, body mass index, whether or not they had cholecystectomy and possible psychosomatic components (somatisation); there were no effects from factors such as smoking, alcohol, the level of education, a history of appendectomy or familiarity with gastrointestinal diseases, civil state, or the use of oral contraceptives.
Sources: en.wikipedia.org
=== Accumulation in buildings === Measurement of radon levels in the first decades of its discovery was mainly done to determine the presence of radium and uranium in geological surveys. In 1956, most likely the first indoor survey of radon decay products was performed in Sweden, with the intent of estimating the public exposure to radon and its decay products. From 1975 up until 1984, small studies in Sweden, Austria, the United States and Norway aimed to measure radon indoors and in metropolitan areas.
The variance is infinite. In a real reactor, diffusion will eventually mix the layers so that the tail of the RTD becomes exponential and the variance finite; but laminar flow reactors can have variance greater than 1, the maximum for CTSD reactors.
Tom Kempinski, playwright and screenwriter Peter Kosminsky (born 21 April 1956); writer, playwright, scriptwriter and screenwriter director and producer; has directed Hollywood movies White Oleander and television films, Warriors, The Government Inspector, The Promise, Wolf Hall and The State; born in London in 1956 to Jewish parents. Hyam Maccoby (Hebrew: חיים מכובי, 1924–2004) was a Jewish-British scholar, dramatist, playwright and author of over fifteen scholarly books, specialising in the study of the Jewish and Christian religious traditions. He was known for his theories of the historical Jesus and the origins of Christianity. Maccoby's play The Disputation has been widely performed, and was broadcast by Channel 4 starring Christopher Lee and Toyah Willcox. Hyam Maccoby's daughter is the anti-Zionist BDS activist, organiser of Jews for Justice for Palestinians and author, Deborah Maccoby, acknowledged for her monograph on Isaac Rosenberg. Patrick Marber, playwright and comedian Laurence Marks (British writer) (born 8 December 1948), producer, scriptwriter, screenwriter and one half of writing duo Marks and Gran (with Maurice Gran). Harold Pinter, Nobel prize-winning playwright; Pinter signed the mission statement of Jews for Justice for Palestinians in 2005 and its full-page advertisement, "What Is Israel Doing? A Call by Jews in Britain", published in The Times on 6 July 2006, and he was a patron of the Palestine Festival of Literature. In April 2008, Pinter signed the statement "We're not celebrating Israel's anniversary".
Clot formation: Once the platelet plug has been formed by the platelets, the clotting factors (a dozen proteins that travel along the blood plasma in an inactive state) are activated in a sequence of events known as 'coagulation cascade' which leads to the formation of fibrin from inactive fibrinogen plasma protein. Thus, a fibrin mesh is produced all around the platelet plug to hold it in place; this step is called secondary hemostasis. During this process some red and white blood cells are trapped in the mesh which causes the primary hemostasis plug to become harder: the resultant plug is called a thrombus or blood clot. The blood clot contains the secondary hemostasis plug with blood cells trapped in it. This is a necessary step for wound healing, but it has the ability to cause severe health problems if the thrombus becomes detached from the vessel wall and travels through the circulatory system; If it reaches the brain, heart or lungs it could lead to stroke, heart attack, or pulmonary embolism respectively.
Mini DisplayPort (mDP) is a standard announced by Apple in the fourth quarter of 2008. Shortly after announcing Mini DisplayPort, Apple announced that it would license the connector technology with no fee. The following year, in early 2009, VESA announced that Mini DisplayPort would be included in the upcoming DisplayPort 1.2 specification. On 24 February 2011, Apple and Intel announced Thunderbolt, a successor to Mini DisplayPort which adds support for PCI Express data connections while maintaining backwards compatibility with Mini DisplayPort based peripherals.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.