Intranasal delivery raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-01-21. Anything still debated is marked as such rather than presented as settled.
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.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
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.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
Mutations alter an organism's genotype and occasionally this causes different phenotypes to appear. Most mutations have little effect on an organism's phenotype, health, or reproductive fitness. Mutations that do have an effect are usually detrimental, but occasionally some can be beneficial. Studies in the fly Drosophila melanogaster suggest that if a mutation changes a protein produced by a gene, about 70 percent of these mutations are harmful with the remainder being either neutral or weakly beneficial.
== Factors influencing inversion == Chiral drugs with stereo-labile configuration are likely to undergo interconversion of the enantiomers that may be enzymatic (biological) or non-enzymatic. Enzyme-mediated conversion is the process of chiral inversion that happens in a living organism. Non-enzymatic inversion of drugs is important and relevant in the pharmaceutical manufacturing process. This may have impact on the shelf-life of a drug and the economic feasibility of the resolution. Inversion can also happen without enzymes when precolumn derivatization is used in enantioselective chromatographic separation techniques. Racemization can also happen in the acidic environment of the stomach and other bodily fluids.
== Honors == Dr. Goldstein is the recipient of several awards, including the Career Scientist Award of the Health Research Council, City of New York; the Van Dyke Memorial Award in Pharmacology from the Columbia University College of Physicians and Surgeons; the Copernicus Medal from the University of Kraków; a citation from the U.S. Department of Health, Education and Welfare "in recognition and appreciation of outstanding work in helping to establish a national program on Biological Response Modifiers"; a Doctor of Science degree (honoris causa) from Wagner College; the Decoration of the Order of Vasco Núñez de Balboa, in the rank of Commander, Panama's highest honor, for "contributions directed to the preservation of human life in the world"; the Distinguished Researcher Award of the George Washington University School of Medicine, and the Chevalier des Palmes Académiques, the highest civilian award of France. He was elected to ΑΩΑ, the National Medical Honor Society in 2007.
Sources: en.wikipedia.org
== Firearms == In June 2018, the Small Arms Survey released a briefing paper entitled "Estimating Global Civilian-Held Firearms". The paper estimates that the total number of guns, both licit and illicit, held by Thai civilians in 2017 was 10,300,000, equating to 15.1 firearms per 100 inhabitants. Comparable figures for other ASEAN nations are: Cambodia, 4.5 per 100 inhabitants; the Philippines, 3.6; Laos, 3.0; Myanmar, 1.6; Vietnam, 1.6; Brunei, 1.4; Malaysia, 0.7; Singapore, 0.3; and Indonesia, zero.
DynoPlot in PyMOL wiki Link to Ramachandran Plot Map of alpha-helix and beta-sheet locations Archived 2006-10-11 at the Wayback Machine Link to Ramachandran plot calculated from protein structures determined by X-ray crystallography compared to the original Ramachan. Proteopedia Ramachandran Plot
== Cyber counterintelligence == Cyber counter-intelligence are measures to identify, penetrate, or neutralize foreign operations that use cyber means as the primary tradecraft methodology, as well as foreign intelligence service collection efforts that use traditional methods to gauge cyber capabilities and intentions.
Eric Stephen Schmitt (born June 20, 1975) is an American attorney and politician serving since 2023 as the junior United States senator from Missouri. A member of the Republican Party, Schmitt served as the 46th state treasurer of Missouri from 2017 to 2019 and as the 43rd Missouri attorney general from 2019 to 2023. Schmitt began his political career as an alderman for Glendale, Missouri. From 2009 to 2017, he represented the 15th district in the Missouri Senate, during which he sponsored major reductions in the state income tax and franchise tax, and expanded benefits and tax exemptions for disabled citizens. As a state senator, Schmitt also led a bipartisan effort in response to the Ferguson unrest to successfully eliminate traffic ticket quotas and limit local revenues from non-traffic fines. In 2016, Schmitt was elected State Treasurer of Missouri. In 2018, Governor Mike Parson appointed Schmitt Missouri Attorney General. He was elected to a full four-year term as attorney general in 2020. As attorney general, he filed or joined lawsuits seeking to invalidate the Affordable Care Act, challenge the results of the 2020 presidential election (in Texas v. Pennsylvania), and, on 25 occasions, oppose the policies of the Joe Biden administration. He also sued school districts and municipalities for implementing mask requirements during the COVID-19 pandemic and sued the government of China and Chinese Communist Party for their alleged role in the pandemic. In 2022, Schmitt was elected to the U.S. Senate, defeating Democratic nominee Trudy Busch Valentine.
Sources: en.wikipedia.org
deoxyadenosine Abbreviated in shorthand with dA. One of the four standard deoxyribonucleosides used in DNA molecules, consisting of an adenine base with its N9 nitrogen bonded to the C1 carbon of a deoxyribose sugar. Adenine bonded to ribose forms an alternate compound known simply as adenosine, which is used in RNA.
Also, the study by Poullain et al., which is often cited to demonstrate the superiority of whey protein hydrolysate by marketers, measured nitrogen balance in rats after three days of starvation, which corresponds to a longer period in humans. The study found that whey protein hydrolysate led to better nitrogen retention and growth than the other proteins studied. However the study's flaw is in the BV method used, as starvation affects how well the body will store incoming protein (as does a very high caloric intake), leading to falsely elevated BV measures. So, the BV of a protein is related to the amount of protein given. BV is measured at levels below the maintenance level. This means that as protein intake goes up, the BV of that protein goes down. For example, milk protein shows a BV near 100 at intakes of 0.2 g/kg. As protein intake increases to roughly maintenance levels, 0.5 g/kg, BV drops to around 70. Pellet et al., concluded that "biological measures of protein quality conducted at suboptimal levels in either experimental animals or human subjects may overestimate protein value at maintenance levels." As a result, while BV may be important for rating proteins where intake is below requirements, it has little bearing on individuals with protein intakes far above requirements.
Polonium is "distinctly metallic" in some ways. Both of its allotropic forms are metallic conductors. It is soluble in acids, forming the rose-coloured Po2+ cation and displacing hydrogen: Po + 2 H+ → Po2+ + H2. Many polonium salts are known. The oxide PoO2 is predominantly basic in nature. Polonium is a reluctant oxidizing agent, unlike its lightest congener oxygen: highly reducing conditions are required for the formation of the Po2− anion in aqueous solution. Whether polonium is ductile or brittle is unclear. It is predicted to be ductile based on its calculated elastic constants. It has a simple cubic crystalline structure. Such a structure has few slip systems and "leads to very low ductility and hence low fracture resistance". Polonium shows nonmetallic character in its halides, and by the existence of polonides. The halides have properties generally characteristic of nonmetal halides (being volatile, easily hydrolyzed, and soluble in organic solvents). Many metal polonides, obtained by heating the elements together at 500–1,000 °C, and containing the Po2− anion, are also known.
== Personal life == On 17 October 2009 McVeigh married his longtime girlfriend, Leanne Tucker. They have a daughter, Ariana, born in March 2011. Mark also had a niece, Luella (the daughter of Sydney's Jarrad McVeigh), born on 25 July 2011 but she died from heart complications barely a month later. Following Essendon's seven-point victory over Port Adelaide, its first over the side since 2004, Mark 'blew a kiss towards to the heavens' in her memory. Essendon's players wore black armbands in the match.
=== Drug delivery === The structure of aquasomes enables dual drug delivery, or the delivery of two drugs simultaneously. This practice aims to enhance the therapeutic efficiency and reduce the side effects of the drugs delivered. Such systems can be useful in treating patients suffering from multiple diseases. Challenges in dual drug delivery include independently controlling release rates of each of the drugs loaded in the system. In a 2019 study by Damera et al., aquasomes were used to deliver bovine serum albumin (BSA) in combination with one of three therapeutic drugs (Coumarin 153, Warfarin, and Ibuprofen), allowing release of a bioactive molecule and a hydrophobic drug simultaneously. Damera et al. suggested that dual drug delivery was enabled by the bioactive molecule layer of the aquasome being BSA. This BSA layer interacted with the hydrophobic therapeutic drugs, and the strength of the binding interactions was shown to affect the release behaviors of the drugs. Dual drug delivery with aquasomes thus shows promise for treatment of patients with coexisting diseases alongside hypoalbuminemia, as the albumin from BSA can treat the hypoalbuminemia while the additional drug treats the disease.
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.