The short version of Intranasal delivery fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-05-08. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
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.
=== Numbers of isotopes per element === Of the 80 elements with a stable isotope, the largest number of stable isotopes observed for any element is ten (for the element tin). No element has nine or eight stable isotopes. Five elements have seven stable isotopes, seven have six stable isotopes, eleven have five stable isotopes, nine have four stable isotopes, five have three stable isotopes, 16 have two stable isotopes (counting 180m73Ta as stable), and 26 elements have only a single stable isotope (of these, 19 are so-called mononuclidic elements, having a single primordial stable isotope that dominates and fixes the atomic weight of the natural element to high precision; two radioactive mononuclidic elements occur as well). In total, there are 251 nuclides that have not been observed to decay. For the 80 elements that have one or more stable isotopes, the average number of stable isotopes is 251/80 ≈ 3.14 isotopes per element.
== Wine == Different bottles, nominally of the same wine, can taste and smell different. One factor is found in the variable oxygen transmission rate (OTR) of cork stoppers, which translates to a degree of bottle variation. Before the advent of inexpensive stainless steel tanks, it was not customary to blend all the wine together and bottle it at once, a process called assemblage. Instead, the winemaker would take his or her siphon from barrel to barrel and fill the bottles from a single barrel at a time. Some traditional and/or idiosyncratic wineries still do this, including Château Musar. Also, buyers and sellers of bulk wine typically do not have access to a multi-million litre tank, and so often the wine will vary depending on which tank it came from. Bottle variation that increases over time typically comes from the packaging. Exposure to heat or light can cause a wine to mature more quickly or even make it taste "cooked". Bottles aged in the chilly cellars of Sweden's alcohol monopoly are famous for tasting younger than the same wine stored at a more typical 13 °C (55 °F). Finally, not all corks seal equally well, and a faulty cork will allow air into the bottle, oxidizing it prematurely. However, a corked wine would be described as a simple fault rather than bottle variation, even though the corked bottle would be clearly different from a non-corked example. Sometimes, it is not clear what causes the variation. Bottles stored together their entire lives, with no obvious faults, can taste completely different.
== History == The dish is named after one of the members of the Stroganov family, a Russian noble family. It has been debated whether it is named after the diplomat Pavel Stroganov or the politician Alexander Stroganov. According to legend, while stationed in Siberia, Pavel Stroganov's chef found the beef to be frozen so solid that it could only be cut into small strips. Another legend attributes its invention to French cooks working for the family, but several researchers point out that the recipe is a refined version of older Russian dishes. In Russian, the dish is called Бефстро́ганов, from the French bœuf Stroganoff.
Reported arrhythmias include bradycardia, atrial fibrillation/flutter, atrioventricular conduction defect, and atrial paralysis. Later in the disease, cardiomyopathy can occur. Sometimes, cardiac involvement is the predominant manifestation of EDMD, with minimal involvement of the skeletal muscles.
Sources: en.wikipedia.org
=== Dependency === Adrenal suppression will begin to occur if prednisone is taken for longer than seven days. Eventually, this may cause the body to temporarily lose the ability to manufacture natural corticosteroids (especially cortisol), which results in dependence on prednisone. For this reason, prednisone should not be abruptly stopped if taken for more than seven days; instead, the dosage should be gradually reduced. This weaning process may be over a few days if the course of prednisone is short but may take weeks or months if the patient had been on long-term treatment. Abrupt withdrawal may lead to an Addisonian crisis. For those on chronic therapy, alternate-day dosing may preserve adrenal function and thereby reduce side effects. Glucocorticoids act to inhibit feedback of both the hypothalamus, decreasing corticotropin-releasing hormone (CRH), and corticotrophs in the anterior pituitary gland, decreasing the amount of adrenocorticotropic hormone (ACTH). For this reason, glucocorticoid analogue drugs such as prednisone down-regulate the natural synthesis of glucocorticoids. This mechanism leads to dependence in a short time and can be dangerous if medications are withdrawn too quickly. The body must have time to begin synthesis of CRH and ACTH and for the adrenal glands to begin functioning normally again. Prednisone may start to result in the suppression of the hypothalamic–pituitary–adrenal (HPA) axis if used at doses 7–10 mg or higher for several weeks. This is approximately equal to the amount of endogenous cortisol produced by the body every day.
The Santuario della Consolata, a sanctuary much frequented by pilgrims, stands on the site of the 10th-century Monastery of St. Andrew, and is a work by Guarini. It was sumptuously restored in 1903. Outside the city are: the Basilica of Our Lady, Help of Christians built by St. John Bosco, the Gran Madre built in 1818 on occasion of the return of King Victor Emmanuel I of Sardinia and Santa Maria del Monte (1583) on Monte dei Cappuccini. In the hills overlooking the city, the Basilica of Superga provides a view of Turin against a backdrop of the snow-capped Alps. The basilica holds the tombs of many of the dukes of Savoy, as well as many of the kings of Sardinia. Superga can be reached by means of the Superga Rack Railway from Sassi suburb. The Basilica of Superga was built by Amadeus II of Savoy as an ex-voto for the liberation of Turin (1706), and served as a royal mausoleum since 1772.
=== Late onset === In milder (or partial) urea cycle enzyme deficiencies, ammonia accumulation may be triggered by illness or stress at almost any time of life, resulting in multiple mild elevations of plasma ammonia concentration [Bourrier et al. 1988]. Patients with partial enzyme deficiencies may have a delay of symptoms for months or years. Indicators that you maybe suffering from OTC deficiency or a urea cycle disorder include "episodes of delirium, erratic behavior, or reduced consciousness, headaches, vomiting, aversion to foods high in protein, and seizures."
== Pharmacology == Itopride acts as a selective dual D2 receptor antagonist and acetylcholinesterase inhibitor. There is evidence that itopride may have prokinetic effects throughout the gastrointestinal tract from the stomach to the end of the colon. The pharmacokinetics of itopride appear to differ between Asian and Caucasian populations, with Caucasians having 30-50 percent lower blood levels of itopride after oral administration. Itopride poorly penetrates across the blood brain barrier because of its high polarity and thus itopride does not tend to cause any central nervous system adverse effects. Itopride has no effect on potassium channels. Similarly to other D2 receptor antagonists, itopride has been found to dose-dependently increase prolactin levels.
Traditionally, homeless shelters ban alcohol. In 1997, as the result of an inquest into the deaths of two people experiencing homelessness who recreationally used alcohol two years earlier, Toronto's Seaton House became the first homeless shelter in Canada to operate a "wet shelter" on a "managed alcohol" principle in which clients are served a glass of wine once an hour unless staff determine that they are too inebriated to continue. Previously, people experiencing homelessness who consumed excessive amounts of alcohol opted to stay on the streets, often seeking alcohol from unsafe sources such as mouthwash, rubbing alcohol or industrial products which, in turn, resulted in frequent use of emergency medical facilities. The programme has been duplicated in other Canadian cities, and a study of Ottawa's "wet shelter" found that emergency room visit and police encounters by clients were cut by half. The study, published in the Canadian Medical Association Journal in 2006, found that serving people experiencing long-term homelessness and who consume excessive amounts of alcohol controlled doses of alcohol also reduced their overall alcohol consumption. Researchers found that programme participants cut their alcohol use from an average of 46 drinks a day when they entered the programme to an average of 8 drinks and that their visits to emergency rooms dropped from 13.5 to an average of 8 per month, while encounters with the police fall from 18.1 to an average of 8.8.
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.
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.