Selank comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-06-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Such programs typically relate to youth, schools, public health, and social assistance. Second, Article 28(2) of the Basic Law guarantees the municipalities "the right to regulate on their own responsibility all the affairs of the local community within the limits set by law". Under this broad statement of competence, local governments can justify a wide range of activities. For instance, many municipalities develop and expand the economic infrastructure of their communities through the development of industrial trading estates. Local authorities foster cultural activities by supporting local artists, building arts centres, and by holding fairs. Local government also provides public utilities, such as gas and electricity, as well as public transportation. The majority of the funding for municipalities is provided by higher levels of government rather than from taxes raised and collected directly by themselves. In five of the German states, there are unincorporated areas, in many cases unpopulated forest and mountain areas, but also four Bavarian lakes that are not part of any municipality. As of 1 January 2005, there were 246 such areas, with a total area of 4167.66 km2 or 1.2% of the total area of Germany. Only four unincorporated areas are populated, with a total population of around 2,000. The table below provides an overview.
A honey bee that is away from the hive foraging for nectar or pollen will rarely sting, except when stepped on or roughly handled. Honey bees will actively seek out and sting when they perceive the hive to be threatened, often being alerted to this by the release of attack pheromones (below). Although it is widely believed that a worker honey bee can sting only once, this is only partially true: although the stinger is in fact barbed so that it lodges in the victim's skin, tearing loose from the bee's abdomen and leading to its death in minutes, this only happens if the skin of the victim is sufficiently thick, such as a mammal's. Honey bees are the only hymenoptera with a strongly barbed sting, though yellow jackets and some other wasps have small barbs. The venom of the honeybee contains histamine, mast cell degranulating peptide, melittin, phospholipase A2, hyaluronidase and acid phosphatase. The three proteins in honeybee venom that are important allergens are phospholipase A2, hyaluronidase and acid phosphatase. In addition, the polypeptide melittin is also antigenic. Bumblebee venom appears to be chemically and antigenically related to honeybee venom. Bees with barbed stingers can often sting other insects without harming themselves. Queen honeybees and bees of many other species, including bumblebees and many solitary bees, have smoother stingers with smaller barbs and can sting mammals repeatedly. The sting's injection of apitoxin into the victim is accompanied by the release of alarm pheromones, a process which is accelerated if the bee is fatally injured.
=== In-line check valve === An in-line check valve is a check valve similar to the lift check valve. However, this valve generally has a spring that will 'lift' when there is pressure on the upstream side of the valve. The pressure needed on the upstream side of the valve to overcome the spring tension is called the 'cracking pressure'. When the pressure going through the valve goes below the cracking pressure, the spring will close the valve to prevent back-flow in the process.
There appear to be at least three distinct receptor complexes that amylin binds to with high affinity. All three complexes contain the calcitonin receptor at the core, plus one of three receptor activity-modifying proteins, RAMP1, RAMP2, or RAMP3.
Swiss chemist Albert Hofmann first synthesized LSD in 1938 and discovered its potent psychedelic effects in 1943 after accidental ingestion. It became widely studied in the 1950s and 1960s. The drug was initially explored for psychiatric use due to its structural similarity to serotonin and safety profile. It was used experimentally in psychiatry for treating alcoholism and schizophrenia. By the mid-1960s, LSD became central to the youth counterculture in places like San Francisco and London, influencing art, music, and social movements through events like Acid Tests and figures such as Timothy Leary, Owsley Stanley and Michael Hollingshead. Its psychedelic effects inspired distinct visual art styles and musical innovations, and caused a lasting cultural impact. However, its association with the counterculture movement of the 1960s led to its classification as a Schedule I drug in the United States in 1970. It was also listed as a Schedule I controlled substance by the United Nations in 1971 and remains without approved medical uses. Despite its legal restrictions, LSD remains influential in scientific and cultural contexts. Research on LSD declined due to cultural controversies by the 1960s, but has resurged since 2009. In 2024, the United States Food and Drug Administration designated LSD (code name MM120 or DT120) as a breakthrough therapy for generalized anxiety disorder. As of 2017, about 10% of people in the United States had used LSD at some point, with 0.7% having used it in the past year.
Sources: en.wikipedia.org
Novel backbones and base pairs as discussed above; XNA artificial replication and transcription polymerases starting generally from T7 RNA polymerase; (16S ribosomal sequences with altered anti-Shine-Dalgarno sequences allowing the translation of only orthogonal mRNA with a matching altered Shine-Dalgarno sequence; and Novel tRNA encoding non-natural aminoacids for an expanded genetic code. In May 2014, researchers announced that they had successfully introduced two new artificial nucleotides into bacterial DNA, and by including individual artificial nucleotides in the culture media, were able to passage the bacteria 24 times; they did not create mRNA or proteins able to use the artificial nucleotides. The artificial nucleotides featured 2 fused aromatic rings.
=== Pharmacokinetics === Literature reviews have stated that fluvoxamine is metabolized primarily by CYP2D6 and to a minor extent by CYP1A2. However, CYP2D6 poor metabolizers do not have considerably higher fluvoxamine levels than extensive metabolizers. Fluvoxamine inhibits oxidative drug metabolising enzymes (particularly CYP1A2, and less potently CYP3A4 and CYP2D6) The mean plasma half-life of fluvoxamine after multiple oral doses of 100 mg/day in healthy, young volunteers was 13.6-15.6 hours. In the elderly, however the half life ranged from 17.4 to 25.9. Steady-state plasma fluvoxamine concentrations were 2-3 fold higher in children than in adolescents.
== External links == "Temozolomide (Temodal)". Cancer Research UK. Archived from the original on 29 August 2021. Retrieved 8 May 2020. "Temozolomide". NCI Dictionary of Cancer Terms. National Cancer Institute. "Temozolomide". National Cancer Institute. 5 October 2006.
==== Productivity and adoption rates ==== While experimental studies show substantial productivity improvements for workers assisted by AI, such as software developers completing tasks 26% faster and mid-level professionals spending 40% less time on routine writing, these gains have not yet translated into economy-wide productivity growth in the UK. McKinsey & Company describes this as the "new productivity paradox", noting that over the past year, the largest contributions to UK productivity growth came from sectors with relatively low AI exposure, such as retail and facilities management. This paradox is partly explained by adoption patterns. A March 2026 survey by the British Chambers of Commerce (BCC) found that while AI adoption among SMEs had accelerated to 54% (up from 25% in 2024), most firms were using generic tools (like chatbots) rather than deeply integrated, bespoke systems. Furthermore, a 2026 global study by PwC showed that nearly 74% of AI's economic value is being captured by just 20% of organisations, being those that use AI to reinvent business models and pursue growth, rather than merely seeking cost reductions.
Sources: en.wikipedia.org
July also saw the addition of two more names to the list of deaths, as Paulson's death became the 22nd linked to the drug, and a 17-year-old member of a high school drill team died at Parkland Memorial Hospital eleven days after being found unconscious on the morning her group was to take its yearbook photo.
== Use and effects == In his book PiHKAL (Phenethylamines I Have Known and Loved) and other publications, Alexander Shulgin and colleagues stated that doses of 1 to 3 mg orally produced clear threshold effects and that it was active at a dose of slightly more than twice that of DOM. It was stated that 10 mg DOBU was required to produce hallucinogenic effects. The drug's duration was listed as "very long". There was limited investigation of its qualitative effects. However, in PiHKAL, at the assessed doses of 2.2 mg and 2.8 mg, it was described as producing paresthesia and difficulty sleeping with few other effects. The effects of higher doses of DOBU have not been described beyond them producing hallucinogenic effects.
In particular, Maricopa County has been targeted by conspiracy theorists for alleged irregularities in how the county voted in the 2020 presidential election; the county's ballots were audited by Republicans in 2021, finding no such claims of voter fraud. Ahead of the 2023 Philadelphia mayoral election and the Pennsylvania primary election, the account for the Philadelphia City Commissioners was unverified, leading to several verified accounts impersonating the commissioners. On May 22, an account aligned with the QAnon conspiracy theory posted an image generated by artificial intelligence that seemingly depicted an explosion near the Pentagon. The fake image was amplified by the Russian propaganda television network RT and the far-right blog Zero Hedge. A verified account posing as Bloomberg News then posted the claim accompanied by several other verified accounts. The S&P 500 fell sharply as a result of the news before rebounding. Several Indian news outlets, including Zee News and Republic TV, aired false reports about the supposed explosion.
== Atrial fibrillation == Pulmonary vein isolation has been the mainstay of atrial fibrillation reduction, but in many cases there are other sources of arrhythmia, including the LoM. Use of ethanol through the VoM has been shown to be an effective way to reduce atrial fibrillation.
== History == The study of lichen acids related to protolichesterinic acid began in 1845, when Schnedermann and Wilhelm Knop isolated lichesterinic acid from Cetraria islandica var. vulgaris. They determined it had a melting point around 120 °C (248 °F) and established its composition as C19H32O4. Further research by H. Sinnhold in 1898 worked with pure lichesterinic acid (melting point 124.5–125 °C). In 1900, Oswald Hesse isolated three varieties (α-, β-, and γ-) of lichesterinic acid from Cetraria islandica, with specific rotations of +27.9°, +27.9°, and +16° respectively. Protolichesterinic acid was first isolated at the beginning of the 20th century by Friedrich Wilhelm Zopf from the lichen Cetraria cucullata (now known as Cladocetraria cucullata). Zopf initially found it alongside usnic acid and noticed that while it showed similarities to lichesterinic acid in some properties, it differed significantly in melting point and other characteristics. The compound was named "protolichesterinic acid" to reflect its close relationship to lichesterinic acid, and the discovery was published in Liebigs Annalen in 1902. After obtaining it in crystalline form through extraction with ether and recrystallization from warm benzol, Zopf determined that protolichesterinic acid formed thin, rhombic, pearly plates that melted at 103–104 °C (217–219 °F), lower than lichesterinic acid's melting point of 124–125 °C (255–257 °F).
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
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.