If you have been reading about Selank 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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
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.
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.
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.
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.
== Function == Cytosolic and membrane-bound forms of glutathione S-transferase are encoded by two distinct supergene families. These enzymes are involved in cellular defense against toxic, carcinogenic, and pharmacologically active electrophilic compounds. At present, eight distinct classes of the soluble cytoplasmic mammalian glutathione S-transferases have been identified: alpha, kappa, mu, omega, pi, sigma, theta and zeta. This gene encodes a glutathione S-transferase belonging to the alpha class. The alpha class genes, which are located in a cluster on chromosome 6, are highly related and encode enzymes with glutathione peroxidase activity that function in the detoxification of lipid peroxidation products. GSTA4 shows very high activity with reactive carbonyl compounds such as alk-2-enals. GSTA4 is highly effective in catalyzing the conjugate addition of reduced glutathione to 4-hydroxynonenal, an important product of peroxidative degradation of arachidonic acid and a commonly used biomarker for oxidative damage in tissue.
An additional major contributor to chemotherapy resistance is inter and intra patient response variability. Inter, referring to differences between patients, and intra referring to differences within an individual patient. The oncology community recognizes inter-patient response variability as a wide-scale phenomenon of pressing concern as variability is even observed in tumors before exposure to targeted treatment. Inter and intra patient response variability further exacerbates the difficulties in ensuring long-term effectiveness of treatment where tumor growth does not progress and shrinkage is permanent. There are many factors at the cellular and genomic level that contribute to variability between patients and within the individual. In a more narrow scope of events, tumor heterogeneity and cellular heterogeneity are the two overarching contributors to this issue. Tumor heterogeneity refers to the diversity of cells within the same tumor microenvironment. Regional and environmental differences within a tumor actively shape its heterogeneity and promote the growth and survival of tumor cells. Variation in oxygen availability, acidity, and growth factors in different regions of the tumor place different selective pressures in each region of the environment, leading to tumor cells with varying sensitivity within the same microenvironment. Additionally, distance from vascular beds in the tumor microenvironment creates an uneven distribution of the targeted drug to all cells in the tumor, failing to effectively kill all of the tumor cells.
Decomposition and pressure buildup — The confinement or unintended heating of concentrated solutions can result in rapid gas evolution, leading to the risk of vessel rupture. Incompatibilities and catalysis by transition metals or organics — The presence of trace contaminants, metal ions, or organic reducing agents may accelerate decomposition or trigger radical pathways. Thermal runaway or self-accelerating decomposition — In the context of peroxide chemistry, it is crucial to consider the self-accelerating decomposition temperature (SADT) and to avoid scaling up reactions without conducting a thorough hazard assessment. Oxidizer hazards in the presence of organics — Hydrogen peroxide acts as an aggressive oxidizer. When in contact with organic substrates, solvents, or flammable materials, the risk of fire or explosion is heightened; therefore, it is essential to ensure that oxidizer storage is kept separate from reducing materials. High-concentration hydrogen peroxide streams, typically above 40%, should be considered hazardous due to concentrated hydrogen peroxide's meeting the definition of a DOT oxidizer according to U.S. regulations if released into the environment. The EPA Reportable Quantity (RQ) for D001 hazardous wastes is 100 pounds (45 kg), or approximately 10 US gallons (38 L), of concentrated hydrogen peroxide.
Sources: en.wikipedia.org
Other polypeptides and proteins such as amylin and the β amyloid peptide do not have a simple consensus sequence and are thought to aggregate through the sequence segments enriched with hydrophobic residues, or residues with high propensity to form β-sheet structure. Among the hydrophobic residues, aromatic amino-acids are found to have the highest amyloidogenic propensity. Cross-polymerization (fibrils of one polypeptide sequence causing other fibrils of another sequence to form) is observed in vitro and possibly in vivo. This phenomenon is important, since it would explain interspecies prion propagation and differential rates of prion propagation, as well as a statistical link between Alzheimer's and type 2 diabetes. In general, the more similar the peptide sequence the more efficient cross-polymerization is, though entirely dissimilar sequences can cross-polymerize and highly similar sequences can even be "blockers" that prevent polymerization.
=== Cognitive impairment and Alzheimer's disease === Two meta-analyses reported lower vitamin E blood levels in AD people compared to healthy, age-matched people. However, a review of vitamin E supplementation trials concluded that there was insufficient evidence to state that supplementation reduced the risk of developing AD or slowed the progression of AD.
Robert John Shiach, Cattleman. For services to the Cattle Industry in Banffshire. William Shiel. For services to Tourism in Northumbria. Trevor Royston Shore, Instructor/Examiner, Dorset County Council Cycle Training Scheme. For services to Road Safety. Joan Silcox. For charitable services in Newcastle-upon-Tyne. Annie Mary Simpson. For services to Education. Sylvia Yvonne Simpson. For services to the Police. Jean Skinner, School Crossing Patrol Warden, Kent County Council. For services to Road Safety. Robert Skinner. For services to the St Andrew's Ambulance Association. David Slater. For services to the community in Worksop Nottinghamshire. Eileen Lorraine Smart, Administrative Assistant, Department of Trade and Industry. Gwenneth Maude Muriel Smewin, lately Headteacher, Dunmore County Infants School, Abingdon, Oxfordshire. For services to Education. Barbara Antoinette Smith, Senior Nurse Manager, Leicester General Hospital. For services to Health Care. Brenda Smith. For charitable services. Carol Beverley Smith, Motor Transport Driver, Ministry of Defence. Graham Arthur Smith, Engineering Manager, Secure Products, Siemens Plessey Systems Ltd. For services to Defence Technology. John McCrindle Smith, . For services to the Magistracy and to the Police Committee in Essex. The Reverend Canon John Reginald Smith. For services to the community in Bury, Greater Manchester. Pauline Smith. For services to the Citizens' Advice Bureau in Sale, Cheshire. Thomas Robert Smith. For services to the community in High Wycombe, Buckinghamshire. Stuart Alan Spears.
Sources: en.wikipedia.org
There are few native natural predators of adult emus still extant. Early in its species history it may have faced numerous terrestrial predators now extinct, including the giant lizard Megalania, the thylacine, and possibly other carnivorous marsupials, which may explain their seemingly well-developed ability to defend themselves from terrestrial predators. The main predator of emus today is the dingo, which was originally introduced by Aboriginals thousands of years ago from a stock of semi-domesticated wolves. Dingoes try to kill the emu by attacking the head. The emu typically tries to repel the dingo by jumping into the air and kicking or stamping the dingo on its way down. The emu jumps as the dingo barely has the capacity to jump high enough to threaten its neck, so a correctly timed leap to coincide with the dingo's lunge can keep its head and neck out of danger. Despite the potential prey-predator relationship, the presence of predaceous dingoes does not appear to heavily influence emu numbers, with other natural conditions just as likely to cause mortality. Wedge-tailed eagles are the only avian predator capable of attacking fully-grown emus, though are perhaps most likely to take small or young specimens. The eagles attack emus by swooping downwards rapidly and at high speed and aiming for the head and neck. In this case, the emu's jumping technique as employed against the dingo is not useful. The birds try to target the emu in the open ground so that it cannot hide behind obstacles.
== Purpose == The primary objectives of PMKSY are to attract investments in irrigation system at field level, develop and expand cultivable land in the country, enhance ranch water use in order to minimize wastage of water, enhance crop per drop by implementing water-saving technologies and precision irrigation. The plan additionally calls for bringing ministries, offices, organizations, research and financial institutions occupied with creation and recycling of water under one platform so that an exhaustive and holistic outlook of the whole water cycle is considered. The goal is to open the doors for optimal water budgeting in all sectors. Tagline for PMKSY is "more crop per drop". The Integrated Watershed Management programme was subsumed into the current PMKSY on 26 October 2015. The core implementation activities of IWMP were unchanged and were as per the Common Guidelines 2008 (Revised 2011) of IWMP. Convergence with other Central and State Government schemes, remains the top of the agenda for the programme towards optimal and judicious utilization of financial resources. Action has also been taken to undertake Natural Resources Management activities by utilizing labour component of MGNREGS and to undertake some of the Entry Point Activities in convergence with Swachh Bharat Mission (Gramin).
Corporate crime refers to crimes committed either by a corporation (i.e., a business entity having a separate legal personality from the natural persons that manage its activities), or by individuals that may be identified with a corporation or other business entity (see vicarious liability and corporate liability). Corporate crimes are motivated by either the individuals desire or the corporations desire to increase profits. The cost of corporate crimes to United States taxpayers is about $500 billion. Note that some forms of corporate corruption may not actually be criminal if they are not specifically illegal under a given system of laws. For example, some jurisdictions allow insider trading. The different businesses that organized crime figures have been known to operate is vast, including but not limited to pharmacies, import-export companies, check-cashing stores, tattoo parlors, zoos, online dating sites, liquor stores, motorcycle shops, banks, hotels, ranches and plantations, electronic stores, beauty salons, real estate companies, daycares, framing stores, taxicab companies, phone companies, shopping malls, jewelry stores, modeling agencies, dry cleaners, pawn shops, pool halls, clothing stores, freight companies, charity foundations, youth centers, recording studios, sporting goods stores, furniture stores, gyms, insurance companies, security companies, law firms, and private military companies. One example of this is a tequila factory in Mexico collaborating with the organized crime group CJNG.
Sources: en.wikipedia.org
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.