This is a working overview of intranasal delivery, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-08 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| 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 |
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.
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.
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.
Scarborough is represented by six ridings for the provincial government and Federal government. Municipal riding boundaries were harmonized within the City of Toronto to match the provincial boundaries in 1999 through provincial legislation called The Fewer Municipal Politicians Act of 1999. This took effect on December 1, 2000. Ridings were represented by two councillors per riding until 2018 when the Government of Ontario reduced this to one councillor per riding. Scarborough now has six councillors.
March 4, 2002: Law concerning patients' rights and the quality of the healthcare system. March 4, 2002: Law concerning family names: the concept of patronymic name is replaced by that of family name; father and mother can give their family name to their child, according to different modalities (choice of one or the other, or combination of both in an order they have defined). March 4, 2002: Law concerning parental authority. July 1, 2002: Creation of the Ministry Delegate for Parity and Professional Equality. March 18, 2003: Law for internal security; it includes elements related to passive solicitation, and others creating the "aggravating circumstance of committing a crime or offense due to the victim's sexual orientation." April 11, 2003: Law concerning the election of regional councilors and representatives to the European Parliament, as well as public aid to political parties; rule of alternating candidates of each gender on electoral lists. June 18, 2003: Law concerning the transmission of family names. July 30, 2003: Law reforming the election of senators, which includes elements related to representation and parity. November 26, 2003: Law concerning the control of immigration, the residence of foreigners in France, and nationality. December 18, 2003: Social Security Financing Act for 2004. March 15, 2004: Law regulating, in application of the principle of secularism, the wearing of signs or outfits manifesting religious affiliation in public schools, colleges, and high schools.
Meat from sheep features prominently in the cuisines of several Mediterranean cultures including Greece, Croatia, Turkey, North Africa, Jordan, and the Middle East, as well as in the cuisines of Iran and Afghanistan. In Greece, for example, it is an integral component of many meals and of religious feasts such as Easter, like avgolemono and magiritsa. It is also popular in the Basque culture, both in the Basque country of Europe and in shepherding parts of the Western United States, where shepherds of Basque descent have been active since the 1850s. In the United States, the Navajo have incorporated mutton and lamb into their traditional cuisine since the introduction of sheep by Spanish explorers and settlers in the 17th century, replacing wild turkey and venison and creating a pastoral culture. In Northern Europe, mutton and lamb feature in many traditional dishes, including those of Iceland, Norway and the United Kingdom. Mutton is popular in Australia. Lamb and mutton are very popular in Central Asia and in certain parts of China, where other red meats may be eschewed for religious or economic reasons. Barbecued mutton is also a specialty in some areas of the United States, chiefly Owensboro, Kentucky, and Canada. Meat from sheep is generally consumed far less in the US than in many European, Central American and Asian cuisines. Average per-capita consumption of lamb in the United States is only 400 grams (14 oz) per year. In Australia, the leg of lamb roast is considered to be the national dish.
Sources: en.wikipedia.org
Her dissertation work focused on investigating molecular-level surface reactivity and kinetics of metal surfaces using electron spectroscopy, laser desorption, and Fourier transform mass spectrometry techniques. She also designed and built peripheral components for a variable temperature, ultra-high vacuum scanning tunneling microscopy system. In 1997, Caldwell Dyson received the Camille and Henry Dreyfus Postdoctoral Fellowship in Environmental Science to study atmospheric chemistry at the University of California, Irvine. There, she investigated reactivity and kinetics of atmospherically relevant systems using atmospheric pressure ionization mass spectrometry, Fourier transform infrared and ultraviolet absorption spectroscopies. In addition, she developed methods of chemical ionization for spectral interpretation of trace compounds. Caldwell Dyson has published and presented her work in numerous papers at technical conferences and in scientific journals.
==== Pharmacokinetics ==== Nabiximol is rapidly absorbed from the buccal mucosa (membranes inside the mouth). It is then widely distributed in different body tissues, especially fatty tissues due to its high lipophilicity. Thus, it may be stored in the fatty tissues for as long as four weeks, which then slowly release back into the blood stream. THC and CBD, the two components of nabiximol is mainly metabolised in the liver via CYP450 enzymes (2C9, 2C19, 2D6 and 3A4) to 11-hydroxy-tetrahydrocannabinol and 7-hydroxy-cannabidiol respectively. Excretion is primarily in faeces.
== Dysfunction == Impaired sudomotor function can occur in any disorder that directly and/or indirectly affects the autonomic nervous system, including diabetes mellitus, amyloidosis, infections, neurodegenerative diseases, multiple system atrophy, and pure autonomic failure. Sudomotor dysfunction can manifest as increased or decreased sweating patterns. Both patterns have the potential to affect an individual's quality of life. Excessive sweating can cause social embarrassment, while insufficient sweating can result in heat intolerance and dry skin. Depending on the severity of dyshidrosis, it may result in hyperkeratosis, rhagades, ulcerations, and poor wound healing due to altered epidermal moisturization. Sudomotor dysfunction is one of the most common and earliest neurophysiological manifestations of small fiber neuropathies. In some cases, it may be the only detectable neurologic manifestation. The gold standard for diagnosis of small fiber neuropathies is Intraepidermal Nerve Fiber Density (IENFD) measured from punch skin biopsies, but this procedure is invasive and inappropriate for long term follow-up. Sudomotor testing can be a valuable diagnostic tool for the early detection of small fiber neuropathies.
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.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.