If you have been reading about anxiolytic 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.
Updated 2026-04-22. Numbers and descriptions here follow the published literature rather than marketing material.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
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.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
== Total synthesis == The total synthesis by E.J. Corey used this proposed biosynthesis to guide their synthetic strategy. The synthesis uses such reactions as the Mannich reaction, Pictet-Spengler reaction, the Curtius rearrangement, and chiral rhodium-based diphosphine-catalyzed enantioselective hydrogenation. A separate synthetic process also involved the Ugi reaction to assist in the formation of the pentacyclic core. This reaction was unprecedented for using such a one pot multicomponent reaction in the synthesis of such a complex molecule.
In July 2006, according to the New York Times, unpublished e-mails from FDA safety official David Graham argued telithromycin had not been proven safe, that safer drugs were available for the same indications, and that the approval was a mistake and should be immediately withdrawn. Between the start of telithromycin's marketing in mid-2004 and September 2006, there were 13 cases of liver failure, including at least four deaths, vision problems, blackouts, syncope, and potentially fatal cases of myasthenia gravis. The Times said that the FDA was embroiled in a "fierce battle" over the approval, fueled by exposure in the press. Senator Charles E. Grassley (R-Iowa, chairman, Senate Finance Committee), Representatives Edward J. Markey (D-Mass) and Henry A. Waxman (D-Calif) held hearings.
==== Atopic dermatitis ==== Light therapy is considered one of the best monotherapy treatments for atopic dermatitis (AD) when applied to patients who have not responded to traditional topical treatments. The therapy offers a wide range of options: UVA1 for acute AD, NB-UVB for chronic AD, and balneophototherapy have proven their efficacy. Patients tolerate the therapy safely but, as in any therapy, there are potential adverse effects and care must be taken in its application, particularly to children. According to a study involving 21 adults with severe atopic dermatitis, narrowband UVB phototherapy administered three times per week for 12 weeks reduced atopic dermatitis severity scores by 68%. In this open study, 15 patients still experienced long-term benefits six months later.
In May 2023, Tim Hortons announced plans to expand into South Korea. In September 2023, officials announced that Tim Hortons would open its first Korean location in Gangnam District, Seoul, within the year. As of October 2024, Tim Hortons has expanded to 13 stores in South Korea.
=== Research === Orally administered açaí has been tested as a contrast agent for magnetic resonance imaging (MRI) of the gastrointestinal system. Its anthocyanins have also been characterized for stability as a natural food coloring agent.
Sources: en.wikipedia.org
All medal achievements listed below are based only on the statistics up to the end of the 2018 Vietnam National Games. The three-code abbreviation for the names of participating sports delegations only began to be used on the system starting from the 2022 Vietnam National Games, so sports delegations that ceased to exist before that time will not have an abbreviation.
For example, an adolescent involved in sports, would likely surround themselves with like-minded active and competitive people. Personal expressiveness, as coined by psychologist A. S. Waterman, are the activities that we choose to express and connect with our "daimon" through subjective experiences. Finally, goal-directed behaviours, are developed through goal setting, where individuals work towards identity establishment. Adolescents recognize their passions, abilities and talents and aim to fulfill their goals and behave in a way that appeases their true self. The study on adolescents was conducted in Italy, Chile and the United States, which produced slightly varied outcomes. Outcomes were contingent on availability, access and choice of opportunities (activities). Socioeconomic context also affected the results, as not all individuals could access the activities that may be more in-line with their true selves. The Personally Expressive Activities Questionnaire (PEAQ) was used to conduct the study. Adolescence was the youngest age group that the PEAQ was used on. The PEAQ asked adolescents to self-report on activities they participate in and describe themselves with self-defining activities. It was reported that 80% of adolescents defined themselves with two to four self-defining activities signifying an understanding in adolescence of self-concept through the domains of leisure, work and academia.
== Personal life == A friend of his from high school introduced Watson to Judith Sjoberg. Not long after that, they were married and moved to Brooks Air Base in San Antonio, Texas. They had two children in Nashville, Jennifer, born in 1970, and Brent born in 1972.
== Further reading == Althouse BM, Hébert-Dufresne L (October 2014). "Epidemic cycles driven by host behaviour". Journal of the Royal Society, Interface. 11 (99) 20140575. doi:10.1098/rsif.2014.0575. PMC 4235258. PMID 25100316.
Sources: en.wikipedia.org
== Chemistry == Metformin hydrochloride (1,1-dimethylbiguanide hydrochloride) is freely soluble in water, slightly soluble in ethanol, but almost insoluble in acetone, ether, or chloroform. The pKa of metformin is 12.4. The usual synthesis of metformin, originally described in 1922, involves the one-pot reaction of a heated solution of dimethylamine hydrochloride and 2-cyanoguanidine.
Nicotine was originally isolated from the tobacco plant in 1828 by chemists Wilhelm Heinrich Posselt and Karl Ludwig Reimann from Germany, who believed it was a poison. Its chemical empirical formula was described by Melsens in 1843, its structure was discovered by Adolf Pinner and Richard Wolffenstein in 1893, and it was first synthesized by Amé Pictet and A. Rotschy in 1904. Nicotine is named after the tobacco plant Nicotiana tabacum, which in turn is named after the French ambassador in Portugal, Jean Nicot de Villemain, who sent tobacco and seeds to Paris in 1560, presented to the French King, and who promoted their medicinal use. Smoking was believed to protect against illness, particularly the plague. However, the "holy herb", tobacco, had first reached Europe by the early 1530s, brought by Spanish explorers. Following its introduction, tobacco rapidly gained popularity in Europe for its stimulating effects, fueled by nicotine's addictive and pharmacological properties and tobacco's widespread embrace as a cure-all. By the early 17th century, this allure fueled its mercilessly laborious cultivation as a cash crop in the Virginia colonies, where John Rolfe's introduction in 1612 rescued Jamestown from economic collapse and famine, transforming it into a prosperous export hub with over 20,000 pounds shipped by 1619 and laying the groundwork for transatlantic trade.
Platelet-rich plasma (PRP), also known as autologous conditioned plasma, is a concentrate of plasma protein derived from whole blood, centrifuged to remove red blood cells but retaining platelets. Though promoted for treating various medical conditions, evidence of its benefits was mixed as of 2020, showing effectiveness in certain conditions and ineffectiveness in others. As a concentrated source of blood plasma and autologous conditioned plasma, PRP contains multiple growth factors and other cytokines that can stimulate the healing of soft tissues and joints. Indications for its use include sports medicine and orthopaedics (such as acute muscle strains, tendinopathy, tendinosis, muscle-fascial injuries, and osteoarthritis) dermatology (for androgenic alopecia, wound healing, and skin rejuvenation), and even proctology (for fistula en ano). Various preparation protocols exist, with the underlying principle of concentrating platelets to 3–5 times physiological levels, then injecting this concentrate into the tissue where healing is desired. Beyond clinical practice, PRP has been utilized in various tissue engineering applications involving bone, cartilage, skin, and soft tissue repair. It serves as a source for the delivery of growth factors and/or cells within tissue-engineered constructs, often in combination with biomaterials.
In 2001, the Center for Science in the Public Interest petitioned the United States Department of Agriculture to require meat packers to remove spinal cords before processing cattle carcasses for human consumption, a measure designed to lessen the risk of infection by variant Creutzfeldt–Jakob disease. The petition was supported by the American Public Health Association, the Consumer Federation of America, the Government Accountability Project, the National Consumers League, and Safe Tables Our Priority. None of the US Department of Health and Human Services targets regarding incidence of foodborne infections were reached in 2007. A report issued in June 2018 by NBC's Minneapolis station using research by both the CDC and the Minnesota Department of Health concluded that foodborne illness is on the rise in the U.S.
CBS News said, "The moderates viewed the deal — after Republicans leaders refused Schumer's offer — as the best possible offer they could secure, arguing that continuing the shutdown would only inflict more pain without any hopes of a better deal." In addition, Senator Tim Kaine (D-Virginia) was won over by a new continuing resolution coming from the White House which reversed the October layoffs.
Sources: en.wikipedia.org
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.