If you have been reading about lyophilization 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 2026-03-21. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 |
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.
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.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
=== Army leadership resignations === In April 2026, Hegseth fired Army Chief of Staff Gen. Randy George which has left the longest break without a service chief in Army history and making him one of eight high ranking members of the military fired or forced out by the secretary of defense. On August 31, 2026 Secretary of the Army Dan Driscoll gave Hegseth his resignation after a face to face meeting Driscoll had with President Trump where he stated his concerns over the number of army generals fired under Hegseth.
==== School of Social Work ==== The School of Social Work offers undergraduate and graduate programs leading to the Doctor of Social Work (DSW). These programs are accredited by the Council on Social Work Education (CSWE).
First, increased dynorphin levels block the release of glutamate, a neurotransmitter involved in plasticity in the hippocampus, which would inhibit new learning. Blocking dynorphin effects would allow glutamate to be released and restore functional plasticity in the hippocampus, reversing the phenomenon of learned helplessness. In addition, blocking dynorphin would enhance dopamine signaling and thus reduce depressive symptoms associated with stress. The authors suggest that KOR antagonists might have potential in treating depression in humans.
Benzodiazepines developed in the former Soviet Union (e.g. phenazepam, gidazepam etc.) Benzodiazepines predominantly used only in Japan (e.g. nimetazepam, flutoprazepam etc.) 4,5-cyclised benzodiazepines (e.g. ketazolam, cloxazolam etc.), and other compounds not researched by Roche Benzodiazepines developed more recently (e.g. remimazolam, QH-ii-066, Ro48-6791 etc.) "Designer" benzodiazepines for which in vitro binding data are unavailable (e.g. flubromazolam, pyrazolam etc.) While binding or activity data are available for most of these compounds also, the assay conditions vary between sources, meaning that in many cases the values are not suitable for a direct comparison. Many older sources used animal measures of activity (i.e. sedation or anticonvulsant activity) but did not measure in vitro binding to benzodiazepine receptors. See for instance Table 2 vs Table 11 in the Chem Rev paper, Table 2 lists in vitro pIC50 values matching those below, while Table 11 has pEC50 values derived from in vivo assays in mice, which show the same activity trends but cannot be compared directly, and includes data for compounds such as diclazepam and flubromazepam which are not available in the main data set. Also note;
February 9 The second impeachment trial of Donald Trump begins. He is acquitted four days later, February 13 with a 57–43 vote in the Senate, ten votes short of the required two-thirds majority for conviction. COVID-19 drug development: The FDA issues an emergency use authorization (EUA) for bamlanivimab and etesevimab. February 11 President Biden terminates the national emergency declaration on the US-Mexico border which President Trump had used to pay for the wall. In Fort Worth, Texas, at least six people are killed in an accident involving 133 vehicles on Interstate 35W, affected by weather conditions left by a snowstorm system. February 12 The United States Senate votes by unanimous consent to award United States Capitol Police officer Eugene Goodman the Congressional Gold Medal for keeping rioters away from the Senate chamber during the storming of the United States Capitol. The U.S. Food and Drug Administration approves Cosela as the first therapy in its class to reduce the frequency of chemotherapy-induced bone marrow suppression. February 15 – House Speaker Nancy Pelosi announces that Congress will establish a 9/11-styled commission to investigate the January 6 riot at the United States Capitol. February 13–17 – A major winter storm kills 58 people in the United States (and 12 in Mexico) and causes over 9,724,000 power outages across 13 states in the Midwest and Southwest, with Southwest Power Pool declaring an "energy emergency". February 17 COVID-19 pandemic: North Dakota confirms their first case of the UK variant of SARS-CoV-2.
Sources: en.wikipedia.org
The chemical nature of the stationary phase. The stationary phase can be coated with some ligands at different bonding densities (how many ligands are bonded per surface area). The composition of the mobile phase. The mobile phase may be made of one solvent, or a mixture of several solvents. The solvents can be mixed at different ratios. Different mobile phases have different properties, such as polarity. When a mobile phase consists of mostly one solvent, with some other solvents added in small amounts, those other solvents are called "mobile phase modifiers". The pH of the mobile phase, which affect the ionization state of the solutes and their polarity. This can be changed with additives such as buffers. Usually, the stationary phase is made of a layer of hydrophobic substrate bonded to the surface of porous silica gel particles. The particles come in various shapes (spheric, irregular), at different diameters (sub-2, 3, 5, 7, 10 μm), with varying pore diameters (60, 100, 150, 300 Å). The particle diameters are often given as mesh numbers. For example, 2500-mesh corresponds to a particle diameter of 5 μm. The hydrophobic substrates are generally alkyl chains, such as C3, C4, C8, C18, or more. The longer the chain, the longer the sample components will be retained. It would make the resolution power higher, but also make the chromatography take longer to run. Most current methods of separation of biomedical materials use C18 columns, sometimes called by trade names, such as ODS (octadecylsilane) or RP-18 (reverse phase 18).
=== Reproductive === Androgens such as testosterone, androstenedione and dihydrotestosterone are required for the development of organs in the male reproductive system, including the seminal vesicles, epididymis, vas deferens, penis and prostate. AAS are testosterone derivatives designed to maximize the anabolic effects of testosterone. AAS are consumed by elite athletes competing in sports like weightlifting, bodybuilding, and track and field. Male recreational athletes take AAS to achieve an "enhanced" physical appearance. AAS consumption disrupts the hypothalamic–pituitary–gonadal axis (HPG axis) in males. In the HPG axis, gonadotropin-releasing hormone (GnRH) is secreted from the arcuate nucleus of the hypothalamus and stimulates the anterior pituitary to secrete the two gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH). In adult males, LH stimulates the Leydig cells in the testes to produce testosterone which is required to form new sperm through spermatogenesis. AAS consumption leads to dose-dependent suppression of gonadotropin release through suppression of GnRH from the hypothalamus (long-loop mechanism) or from direct negative feedback on the anterior pituitary to inhibit gonadotropin release (short-loop mechanism), leading to AAS-induced hypogonadism.
=== Linus Pauling Institute === Robinson was the president, director, and a research professor with tenure at the institute. In June 1978, Robinson was asked to consult with the Executive Committee of the Linus Pauling Institute regarding important decisions involving the Institute. The members of the Executive Committee included Robinson, Pauling, and Executive Vice President Richard Hicks. The same day Robinson was asked to consult, he (Robinson) dismissed Hicks by terminating the fund raising services agreement employing Hicks, claiming that Hicks had failed to generate the substantial donations expected of him. Disturbed by Robinson's swift actions against Hicks, Pauling declared that he no longer had "trust and confidence in Robinson", and asked him to resign immediately. Robinson requested thirty days to consider the resignation and ultimately refused. Pauling called a meeting of the board of trustees regarding Robinson's refusal to resign. The board granted Robinson a leave of absence, and passed all executive authority to Pauling, later electing him president and director of the institute.
=== Behavioral therapy === Paralleling the variety of medical treatments, there are many forms of psychotherapy and community support for treating OUD. The primary evidence-based psychotherapies include cognitive behavioral therapy (CBT), motivational enhancement therapy (MET), contingency management (CM), and twelve-step programs. Community-based support such as support groups (e.g., Narcotics Anonymous) and therapeutic housing for those with OUD is also an important aspect of healing.
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.
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.