This is a working overview of Intranasal route, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-05 and is reviewed periodically as new material appears.
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
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.
Proteins that are destined for degradation by the 26S proteasome require two main elements: 1) the attachment of a small protein called ubiquitin and 2) an unstructured region of about 25 amino acids. Proteins that lack this unstructured region can have another motor, cdc48 in yeast or P97 in humans, generate this unstructured region by a unique mechanism where ubiquitin is unfolded by cdc48 and its cofactors Npl4/Ufd1. The tagging of a target protein by ubiquitin is catalyzed by cascade of enzymes consisting of the Ubiquitin-activating enzyme (E1), Ubiquitin-conjugating enzyme (E2), and ubiquitin ligases (E3). Once a protein is tagged with a single ubiquitin molecule, this is a signal to other ligases to attach additional ubiquitin molecules. The result is a polyubiquitin chain that is bound by the proteasome, allowing it to degrade the tagged protein in an ATP dependent manner. The degradation process by the proteasome yields peptides of about seven to eight amino acids long, which can then be further degraded into shorter amino acid sequences and used in synthesizing new proteins.
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Inhaling helium can be dangerous if done to excess, since helium is a simple asphyxiant and so displaces oxygen needed for normal respiration. Fatalities have been recorded, including a youth who suffocated in Vancouver in 2003 and two adults who suffocated in South Florida in 2006. In 1998, an Australian girl from Victoria fell unconscious and temporarily turned blue after inhaling the entire contents of a party balloon. Inhaling helium directly from pressurized cylinders or even balloon filling valves is extremely dangerous, as high flow rate and pressure can result in barotrauma, fatally rupturing lung tissue. Death caused by helium is rare. The first media-recorded case was that of a 15-year-old girl from Texas who died in 1998 from helium inhalation at a friend's party; the exact type of helium death is unidentified. In the United States, only two fatalities were reported between 2000 and 2004, including a man who died in North Carolina of barotrauma in 2002. A youth asphyxiated in Vancouver during 2003, and a 27-year-old man in Australia had an embolism after breathing from a cylinder in 2000. Since then, two adults asphyxiated in South Florida in 2006, and there were cases in 2009 and 2010, one of whom was a Californian youth who was found with a bag over his head, attached to a helium tank, and another teenager in Northern Ireland died of asphyxiation. At Eagle Point, Oregon a teenage girl died in 2012 from barotrauma at a party. A girl from Michigan died from hypoxia later in the year.
=== Neuroprotective and adjunctive therapies === The neuroprotective role of B12 supplements is not fully understood, although numerous animal studies support their role in recovery at both the molecular and structural levels. Current animal studies suggest B12 may have neuroprotective effects, specifically at maintaining nerve conduction through the process of saltatory conduction. Currently, 15 animal studies highlight B12 for its role in nerve cell survival and remyelination. In instances of post-acute injury, B12 supplementation may support nerve cell survival, potentially reducing degeneration that can lead to axonotmesis. In neurapraxia, B12 may serve to support the reconstruction site for myelin sheaths. Within the broader context of neuroscience, cobalamin (B12) has been established as an enzyme cofactor, a necessary precursor for myelin synthesis and neurotransmitter regulation. B12 deficiency is correlated to neurological complications and neuropathy; however, the latter and overall role of B12 is perhipheral nere recovery is still under investigation.
Sources: en.wikipedia.org
=== Bosnia and Herzegovina, Croatia, Montenegro, Serbia, Macedonia === "Pola pola" ("half and half") is a slang term for the drink spritzer, made out of equal parts of white wine or rosé wine and carbonated water. Different ratios of wine and carbonated water are named with various slang terms, depending on the region. "Pola pola" is also known as "litra i voda" (one bottle of wine and one bottle of carbonated water), as well as "Litar-litar" (as in 1 liter of wine, 1 liter of water) and "Gemišt".
Distinguishing features of Thomas's early poetry include its verbal density, use of alliteration, sprung rhythm and internal rhyme, with some critics detecting the influence of the English poet Gerard Manley Hopkins. Walford Davies suggests there is little else than "a coincidence of poetic temperament." Thomas himself wrote to Henry Treece, who had compared the two, denying any significant influence. Thomas also employed fixed verse form, such as in the villanelle "Do not go gentle into that good night". Thomas greatly admired Thomas Hardy, who is regarded as an influence. When Thomas travelled in America, he recited some of Hardy's work in his readings. Other poets from whom critics believe Thomas drew influence include James Joyce, Arthur Rimbaud and D. H. Lawrence. William York Tindall, in his 1962 study, A Reader's Guide to Dylan Thomas, finds comparison between Thomas's and Joyce's wordplay, while he notes the themes of rebirth and nature are common to the works of Lawrence and Thomas. Although Thomas described himself as the "Rimbaud of Cwmdonkin Drive", he stated that the phrase "Swansea's Rimbaud" was coined by poet Roy Campbell. Critics have explored the origins of Thomas's mythological pasts in his works such as "The Orchards", which Ann Elizabeth Mayer believes reflects the Welsh myths of the Mabinogion. Thomas's poetry is notable for its musicality, most clear in "Fern Hill", "In Country Sleep", "Ballad of the Long-legged Bait" and "In the White Giant's Thigh".
Kallingal married director Aashiq Abu on 1 November 2013, at the Kakkanad Registration Office, Kochi. Ahead of the ceremony, the couple donated ₹1 million towards the welfare of cancer patients at the General Hospital, Ernakulam, and ₹25,000 towards the dietary kitchen at the same hospital.
Sources: en.wikipedia.org
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.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.