Everything below concerns Intranasal route. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
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.
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.
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.
== Awards and honours == 2007 Donald F. Steiner Award for Outstanding Diabetes Research, University of Chicago 2008 Prix Galien Canada for Outstanding Pharmaceutical Research 2009 Clinical Investigator Award, Endocrine Society 2012 Claude Bernard Prize, European Association for the Study of Diabetes 2012 Fellow of the Royal Society of Canada 2013 Oon International Award for Preventative Medicine, University of Cambridge 2014 Banting Medal for Scientific Achievement, American Diabetes Association 2014 Manpei Suzuki Foundation International Prize for Diabetes, Japan 2015 Fellow of the Royal Society 2015 Officer of the Order of Canada 2017 Rolf Luft Award in Endocrinology and Diabetes Research, Karolinska Institute 2017 Harrington Prize for Innovation in Medicine, American Society for Clinical Investigation and the Harrington Institute (co-recipient with Joel Habener and Jens Juul Holst) 2019 Harold Hamm International Prize for Biomedical Research in Diabetes 2019 Novo Nordisk Foundation and European Association for the Study of Diabetes Prize for Excellence in Diabetes Research (watch the mini documentary about Drucker produced by the Novo Nordisk Foundation for the occasion) 2019 Lifetime Achievement Award, Helmholtz Diabetes Centre, Germany 2020 John Baxter Award for Entrepreneurship, Endocrine Society 2020 Transatlantic Medal, Society for Endocrinology 2020 Warren Alpert Foundation Prize for Biomedical Research (co-recipient with Joel Habener and Jens Juul Holst) 2021 International Member, National Academy of Sciences 2021 Canada Gairdner International Award (co-recipient with Joel Habener and Jens Juul Holst) 2022 Inductee of the Canadian Medical Hall of Fame 2023 Wolf Prize in Medicine 2023 International Member of the National Academy of Medicine 2023 VinFuture Prize for Innovators with Outstanding Achievements in Emerging Fields (co-recipient with Joel Habener, Jens Juul Holst and Svetlana Mojsov) 2024 Princess of Asturias Award for Technical and Scientific Research (co-recipient with Jeffrey M. Friedman, Joel Habener, Jens Juul Holst and Svetlana Mojsov) 2024 Time100 Most Influential People and Time100 Health 2024 Golden Plate Award, American Academy of Achievement 2024 Fred Conrad Koch Lifetime Achievement Award, Endocrine Society 2024 TOPS Research Achievement Award, The Obesity Society 2025 Warren Triennial Prize, Massachusetts General Hospital (co-recipient with Joel Habener and Svetlana Mojsov) 2025 BBVA Foundation Frontiers of Knowledge Award in Biology and Biomedicine (co-recipient with Joel Habener, Jens Juul Holst and Svetlana Mojsov) 2025 Solomon A. Berson Award, American Physiology Society 2025 Breakthrough Prize in Life Sciences (co-recipient with Joel Habener, Jens Juul Holst, Svetlana Mojsov and Lotte Bjerre Knudsen) 2026 Governor General's Innovation Award
lagging strand In DNA replication, the nascent strand for which DNA polymerase's direction of synthesis is away from the replication fork, which necessitates a complex and discontinuous process in contrast to the streamlined, continuous synthesis of the other nascent strand, known as the leading strand, which occurs simultaneously. Because DNA polymerase works only in the 5' to 3' direction, but the lagging strand's overall direction of chain elongation must ultimately be the opposite (i.e. 3' to 5', toward the replication fork), elongation must occur by an indirect mechanism in which a primase enzyme synthesizes short RNA primers complementary to the template DNA, and DNA polymerase then extends the primed segments into short chains of nucleotides known as Okazaki fragments. The RNA primers are then removed and replaced with DNA, and the Okazaki fragments are joined by DNA ligase.
== Nixon's visit to Moscow == At the time of the Easter Offensive, Kissinger was deeply involved in planning for Nixon's visit to Moscow in May 1972. The offensive brought to the fore the differences between Nixon and Kissinger. Nixon threatened to cancel his summit with Leonid Brezhnev in Moscow if the Soviet Union did not force North Vietnam to end the Easter Offensive at once, saying: "Whatever else happens, we cannot lose this war. The summit isn't worth a damn if the price for it is losing in Vietnam". Nixon, in his instructions to Kissinger, stated that he viewed the relations with the Soviet Union through the prism of the Vietnam War, and if the Soviets were not prepared to help, Kissinger "should just pack up and come home". Kissinger, for his part, believed that Nixon was massively exaggerating Soviet influence in North Vietnam and no longer believed, if he ever did, in Nixon's "linkage" concept. Kissinger feared that Nixon was obsessed with Vietnam, and damaging relations with the Soviet Union over Vietnam would destabilize the international power balance by increasing American-Soviet tensions. On 20 April 1972, Kissinger arrived in Moscow without informing the U.S. ambassador Jacob D. Beam, and then went to have tea with Brezhnev in the Kremlin. Nixon, as usual when under stress, departed for a marathon drinking session with Rebozo at Camp David, and via Haig kept sending messages to Kissinger urging him to be tough with Brezhnev.
Blood is composed of a fluid portion, called plasma, and a cellular portion that contains red blood cells, white blood cells and platelets. The complete blood count evaluates the three cellular components of blood. Some medical conditions, such as anemia or thrombocytopenia, are defined by marked increases or decreases in blood cell counts. Changes in many organ systems may affect the blood, so CBC results are useful for investigating a wide range of conditions. Because of the amount of information it provides, the complete blood count is one of the most commonly performed medical laboratory tests. The CBC is often used to screen for diseases as part of a medical assessment. It is also called for when a healthcare provider suspects a person has a disease that affects blood cells, such as an infection, a bleeding disorder, or some cancers. People who have been diagnosed with disorders that may cause abnormal CBC results or who are receiving treatments that can affect blood cell counts may have a regular CBC performed to monitor their health, and the test is often performed each day on people who are hospitalized. The results may indicate a need for a blood or platelet transfusion. The complete blood count has specific applications in many medical specialties. It is often performed before a person undergoes surgery to detect anemia, ensure that platelet levels are sufficient, and screen for infection, as well as after surgery, so that blood loss can be monitored.
=== Peptide synthesis === Continuing and expanding the tradition of the University of Athens within the subject, starting from Zervas of Bergmann-Zervas carbobenzoxy method fame, Photaki initially worked on further refinement of suitable protecting groups for oligopeptide synthesis. She investigated with Zervas new types of protection such as N-protection with benzyl phosphate esters (N-phosphamide derivatives), S-protection using trityl, benzhydryl or benzoyl groups (as part of the greater effort for the synthesis of asymmetric cysteine-containing peptides), N-protection using the o-nitrophenylsulfenyl (NPS) group discovered in their Athens laboratory, or S-protection using the p-methoxycarbobenzoxy group (a modification of the Z group). With the above methodologies she embarked on the synthesis of complex polypeptides, especially fragments of enzyme active sites and peptide hormones. Some notable achievements in papers Photaki co-authored include the first synthesis of the 20-membered insulin intra-chain ring or –following her research under du Vigneaud– several previously inaccessible oxytocin analogues (e.g. 4-deamido-oxytocin) and a novel oxytocin synthesis via a different route than the du Vigneaud synthesis. In later years she also examined the preparation of biologically active atypical peptides such as Nω-arginine or lanthionine-containing peptides.
Sources: en.wikipedia.org
== Medical uses == Naltrexone/bupropion is indicated, as an adjunct to a reduced-calorie diet and increased physical activity, as anti-obesity medication for the management of weight in adults with an initial body mass index (BMI) of:
κ-Bungarotoxin can be extracted from the Bungarus multicinctus venom glands. Upon extraction, the κ-bungarotoxin needs to be isolated and purified for further use. Another way to yield κ-bungarotoxin is by chemically synthesizing the gene which codes for the toxin. Transplanting this gene into Escherichia coli does not result in a stable product. However, after fusing the toxin with rat intestinal fatty acids, the fusion proteins differed only in cleavage sites. Hereafter, the κ-bungarotoxin could be isolated and purified. Further research discovered that an active form of yeast, Pichia pastoris, was able to make biologically active Kappa-Bungarotoxin. This process does not require additional manipulation of genes or proteins. Furthermore, the produced quantity is five times higher than that of E. coli produced κ-bungarotoxin.
=== Antisense pharmaceuticals === In the United States, the Food and Drug Administration (FDA) has approved the phosphorothioate antisense oligonucleotides fomivirsen (Vitravene) and mipomersen (Kynamro) for human therapeutic use in antisense therapy. To prevent degradation of the therapeutic oliogoneucleotides, chemical modification is usually required. The most common chemical modification on the oligonucleotides is adding a phosphorothioate linkage to the backbones. However, the phosphrothioate modification can be proinflammatory. Adverse effects including fever, chills or nausea have been observed after local injection of phosphrothioate modified oligonucleotides. Gapmers often utilize nucleotides modified with phosphorothioate (PS) groups. Miravirsen is an antisense phosphorothioate oligonucleotides that is additionally a locked nucleic acid gapmer. Other antisense oligonucleotides using phosphorothioates include afovirsen, aganirsen, alicaforsen, bepirovirsen, custirsen, drisapersen, eplontersen, evazarsen, gataparsen, inotersen, IONIS-GCCRRx, nusinersen, oblimersen, olezarsen, pelacarsen, sefaxersen, tofersen, and volanesorsen. First-generation anti-miRNA oligonucleotides utilized 2’-O-Methyl RNA nucleotides with phosphorothioate internucleotide linkages positioned at both ends to prevent exonuclease attack. This was also shown to have an effect on target affinity. Using the P-S mutation was shown to decrease the Tm of the oligonucleotide, which leads to a lower target affinity.
Storage refers to keeping the waste until it is treated on-site or transported off-site for treatment or disposal. There are many options and containers for storage. Regulatory agencies may limit the time for which waste can remain in storage. Handling is the act of moving biomedical waste between the point of generation, accumulation areas, storage locations and on-site treatment facilities. Workers who handle biomedical waste must observe standard precautions.
Non-volatile materials were discovered in 2015 to also exhibit a 'reactive Leidenfrost effect', whereby solid particles were observed to float above hot surfaces and skitter around erratically. Detailed characterization of the reactive Leidenfrost effect was completed for small particles of cellulose (~0.5 mm) on high temperature polished surfaces by high speed photography. Cellulose was shown to decompose to short-chain oligomers which melt and wet smooth surfaces with increasing heat transfer associated with increasing surface temperature. Above 675 °C (1,247 °F), cellulose was observed to exhibit transition boiling with violent bubbling and associated reduction in heat transfer. Liftoff of the cellulose droplet (depicted at the right) was observed to occur above about 750 °C (1,380 °F), associated with a dramatic reduction in heat transfer. High speed photography of the reactive Leidenfrost effect of cellulose on porous surfaces (macroporous alumina) was also shown to suppress the reactive Leidenfrost effect and enhance overall heat transfer rates to the particle from the surface. The new phenomenon of a 'reactive Leidenfrost (RL) effect' was characterized by a dimensionless quantity, (φRL= τconv/τrxn), which relates the time constant of solid particle heat transfer to the time constant of particle reaction, with the reactive Leidenfrost effect occurring for 10−1< φRL< 10+1.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.