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 2026-06-08. Numbers and descriptions here follow the published literature rather than marketing material.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
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 |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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 with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
== General references == Catholic Encyclopedia Neher in Kirchenlexikon I, 1184–89 De Rubeis, Monumenta Eccles. Aquil. (Strasburg, 1740) Ferdinando Ughelli, Italia Sacra, I sqq.; X, 207 Cappelletti, Chiese d'Italia, VIII, 1 sqq. Menzano, Annali del Friuli (1858–68) Paschini, Sulle Origini della Chiesa di Aquileia (1904) Glaschroeder, in Buchberger's Kirchl. Handl. (Munich, 1904), I, 300-301 Hefele, Conciliengesch. II, 914–23. For the episcopal succession, see P. B. Gams, Series episcoporum (Ratisbon, 1873–86), and Eubel, Hierarchia Catholica Medii Aevi (Muenster, 1898). Glaser, Franz; Pochmarski, Erwin (2012). Aquileia. Der archäologische Führer (in German). Darmstadt/Mainz: Philipp von Zabern. ISBN 978-3-8053-4277-3.
This enables researchers to report a ratio for the expression of the genes of interest divided by the expression of the selected normalizer, thereby allowing comparison of the former without actually knowing its absolute level of expression. The most commonly used normalizing genes are those that code for the following molecules: tubulin, glyceraldehyde-3-phosphate dehydrogenase, albumin, cyclophilin, and ribosomal RNAs.
== Early life stress == MeCP2 monitors the response to early life stress. Early life stress is correlated with hyper-phosphorylation of the MeCP2 protein in paraventricular nucleus of the hypothalamus. This thus causes a reduced occupancy of MeCP2 at the AVP gene's promoter region, and therefore elevated levels of AVP. Vasopressin is a primary hormone involved in the Hypothalmic-Pituitary-Adrenal Axis, the connectivity in the brain that regulates processing of and reaction to stress. Decreased functioning of the MeCP2 protein thus upregulates the neuronal stress response.
Absorbance Units Full Scale (AUFS) or Absorption Units Full Scale is a unit of absorbance intensity that denotes the output of a spectrophotometer. The acronym AUFS can also be written out as Absorbance Units per Full Scale Deflection. AUFS is an arbitrary unit of the maximum ultraviolet or visible light absorbance intensity measured by a detector. It can be used in chemical analysis to quantify components in a mixture, as each component's integrated peak area corresponds to their relative abundance. AUFS is given as a number ranging from 0 to 1, where a measurement of 1 AUFS indicates an absorbance reading of 1 at full deflection. Analytical chemistry Chromatography Spectroscopy
Sources: en.wikipedia.org
=== Biosimilars === Abasaglar was authorized for medical use in the European Union in September 2014. Lusduna was authorized for medical use in the European Union in January 2017. Semglee was authorized for medical use in the European Union in March 2018. Semglee (glargine-yfgn) was approved for medical use in the United States in July 2021. Rezvoglar (glargine-aglr) was approved for medical use in the United States in December 2021. In November 2025, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Ondibta, intended for the treatment of diabetes. The applicant for this medicinal product is Gan & Lee Pharmaceuticals Europe GmbH. Ondibta is a biosimilar medicinal product that is highly similar to the reference product Lantus, which was authorized in the EU in June 2000. Ondibta was authorized for medical use in the European Union in January 2026.
== Classification == Surfactants are compounds with hydrophilic "heads" and hydrophobic "tails." The "heads" of surfactants are polar and may or may not carry an electrical charge. The "tails" of most surfactants are fairly similar, often consisting of a hydrocarbon chain (linear or branched) and may comprise aromatic units. Most commonly, surfactants are classified according to the polarity of their head group: A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative, charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic, or amphoteric.
=== Viet Minh === According to Arthur J. Dommen, the Việt Minh assassinated 100,000–150,000 civilians during the war out of a total civilian death toll of 400,000. Viet Minh militants employed terrorist attacks throughout the conflict as a systematic practice, often targeting European and Eurasian civilians. One of the worst attacks on Europeans was on 21 July 1952, when Viet Minh militants, using grenades, Sten guns, and machetes, massacred twenty unarmed people at a military hospital in Cap St. Jacques—eight officers on sick leave, six children, four Vietnamese servants, and two women. Many French Union and Vietnamese National Army prisoners died in the Việt Minh POW camps as a result of torture. In the Boudarel Affair, French Communist militant Georges Boudarel was discovered to have used brainwashing and torture against French Union POWs in Việt Minh reeducation camps. The French national association of POWs brought Boudarel to court for a war crime charge.
An mRNA vaccine (or RNA vaccine) is a novel type of vaccine which is composed of the nucleic acid RNA, packaged within a vector such as lipid nanoparticles. Among the COVID-19 vaccines are a number of RNA vaccines to combat the COVID-19 pandemic and some have been approved or have received emergency use authorization in some countries. For example, the Pfizer-BioNTech vaccine and Moderna mRNA vaccine are approved for use in adults and children in the US.
=== Foreign operations in China === Mengniu-Arla, a joint-venture between Danish/Swedish co-operative Arla Foods and Mengniu halted production on 16 September 2008 after three of 28 tests taken from Mengniu showed traces of melamine; the contaminated batches had been recalled. Mengniu, milk supplier to Starbucks, was replaced by Vitasoy when the coffee retailer eschewed milk in favour of soya milk in its China operations. KFC also suspended selling Mengniu milk. Seoul-headquartered Lotte Group, a major snacks maker, recalled its Koala's March cookies in Hong Kong and Macau because of contamination, and promised to "look deeply into all the details of the manufacturing process" to preserve customer confidence. The range was also ordered off Dutch and Slovak shelves. Other products were seized when samples tested positive in Malta. On 29 September, British confectionery group Cadbury recalled all chocolate products made in its Chinese factories due to concerns about melamine contamination, affecting products intended for markets in China, Taiwan, Hong Kong, Japan, Korea and Australia. Tests in Hong Kong found amounts of melamine in China-made Dairy Milk products which exceeded safety regulations. On 30 September, Unilever recalled its Lipton milk tea powder after the company's internal checks found traces of melamine in the Chinese powdered milk used as an ingredient. Heinz recalled cases of baby cereal in Hong Kong after discovering they contained melamine.
Sources: en.wikipedia.org
=== Wet symptoms === Circulatory shock Diarrhea (feces which resemble more liquid than solid) Hemorrhage (bleeding) and sometimes bleeding diathesis (a person loses more blood than usual from an injury – for example, getting only a little cut, and losing a lot of blood) Petechiae (small red or purple spots) Swelling caused by edema The severity of symptoms varies with both individual immune competence and the type of virus. The "VHF syndrome" causes bleeding diathesis, capillary leak, and circulatory shock. It happens to most people who have Filoviridae infections (such as Ebola virus or Marburg virus), Crimean–Congo hemorrhagic fever (CCHF), or the South American hemorrhagic fevers (which are caused by Arenaviridae). VHF syndrome only happens to a small minority of people who have dengue fever or Rift Valley fever.
Wittman defeated Democratic nominee Vangie Williams. With the Republicans losing their remaining seat based in the Washington suburbs, as well as seats in Hampton Roads and the Richmond suburbs, Wittman was left as the only Republican holding a seat east of Charlottesville.
==== Mesopotamia ==== According to the expert on Middle Eastern history of chemistry Martin Levey, potassium alum is one of the few compounds known to the ancients that can be found relatively pure in nature, as well as one of only a few chemicals used in Mesopotamian chemical technology that can be identified with certainty. Both native and imported potassium alum was used. Together with other agents, potassium alum was used in glass-making, tanning, and in the dyeing of cloth, wood, and possibly hair. A tanning process using potassium alum is described in tablets from the first millennium BCE. When Levey wrote his article in 1958, no description of the dyeing process had been found, so it is not known how potassium alum was used in it. In Mesopotamian medicine potassium alum was used extensively, for example against itch, jaundice, some eye condition, and unidentified ailments. According to Levey, potassium alum was used in "classical times" as a flux when soldering copper, in the fireproofing of wood, and in the separation of silver and gold, but that there is no evidence that these uses existed in Mesopotamia.
==== Australia ==== Mescaline is considered a schedule 9 substance in Australia under the Poisons Standard (February 2020). A schedule 9 substance is classified as "Substances with a high potential for causing harm at low exposure and which require special precautions during manufacture, handling or use. These poisons should be available only to specialised or authorised users who have the skills necessary to handle them safely. Special regulations restricting their availability, possession, storage or use may apply."
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
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.