This is a working overview of Intranasal delivery, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-19. Anything still debated is marked as such rather than presented as settled.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or below | For lyophilized powder, long term |
| Common analytical method | Reverse-phase HPLC | Usually paired with mass spectrometry |
| Typical reported purity | At or above 95 percent by area | Research-grade material |
| Aqueous solubility | High | Solutions used in laboratory assays |
| Moisture sensitivity | Hydrolyzes in solution | Aseptic handling reduces degradation |
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.
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.
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.
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.
== B == B-cell lymphoma – B cells – B lymphocytes (B cells) – bactericidal – bacteriostatic – bacterium – baculovirus – baseline – basophil – bDNA test – beta-2 microglobulin (β2M) – bilirubin – bioavailability – biological response modifiers (BRMs) – biopsy – biotechnology – blinded study – blips – blood–brain barrier – body fat redistribution (BFR) syndrome – body fluids – bone marrow – bone marrow suppression – booster – branched DNA assay – breakthrough infection – Broadway Cares/Equity Fights AIDS – bronchoscopy – budding – buffalo hump – bugchasing and giftgiving – Burkitt's lymphoma
This effect, called the quasispecies model, results in immense variation in any given sample of virus, and gives the opportunity for natural selection to favor viral strains with the highest fitness every time the virus is spread to a new host. Recombination, the joining of two different viral variants, and reassortment, the swapping of viral gene segments among viruses in the same cell, also play a role in resistance, especially in influenza. Antiviral resistance has been reported in antivirals for herpes, HIV, hepatitis B and C, and influenza, but antiviral resistance is a possibility for all viruses. Mechanisms of antiviral resistance vary between virus types.
=== Familial (ATTRm-CM) === This type is caused by mutations of genes encoding amino acids of the transthyretin protein (TTR) causing transthyretin misfolding. Due to the multiple number of potential genetic causes (approximately 130 gene variants are known) the incidence of this form is variable in different populations, depending on the genetic variant. The vast majority of familial cardiac amyloidosis still present after the age of 60. A common mutation is the TTR gene mutation Val122Ile. It is estimated that 3.5–4% of African Americans in the United States have the Val 122lle mutation. This type of amyloidosis can be identified by genetic testing for protein mutation. Histological evaluation involves special stains being utilized to visualize the amyloid deposits. One such stain is Congo Red, which binds specifically to the amyloid deposits and can be characterized by various lighting methods. Under polarized light, the amyloid deposits show characteristic apple green birefringence, and under plain light the deposits will appear a light salmon pink color. Familial amyloidosis usually causes a combination of heart failure and peripheral neuropathy or autonomic neuropathy. Whereas wild-type transthyretin amyloidosis usually causes heart failure, with neuropathy being more rare.
== Routine Schedule of Immunization == Every Wednesday is designated as immunization day and is adopted in all parts of the country. Immunization is done monthly in barangay health stations, quarterly in remote areas of the country.
Sources: en.wikipedia.org
The prevalence of MS shows a geographic gradient: it is more common in people who live farther from the equator (e.g., those who live in northern regions of the world). Exceptions include ethnic groups that are at low risk and that live far from the equator, such as the Sami, Amerindians, Canadian Hutterites, New Zealand Māori, and Canada's Inuit, as well as groups that have a relatively high risk and that live closer to the equator such as Sardinians, inland Sicilians, Palestinians, and Parsi. The geographical gradient can, at least in part, be explained by exposure to sunlight and resulting vitamin D levels. Vitamin D plays various roles in the immune system, including helping the body get rid of pathogens and regulating immune tolerance. Low vitamin D levels are a risk factor for developing MS and for disease progression beyond the first attack. Sunlight exposure may reduce risk independently from vitamin D. While there are dietary sources of vitamin D (e.g. fatty fish and some mushrooms), this usually is not enough to meet the body's need. The risk of MS tracks the sunlight exposure in childhood.
Using these techniques, a model of human metabolism has now been produced, which will guide future drug discovery and biochemical research. These models are now used in network analysis, to classify human diseases into groups that share common proteins or metabolites. Bacterial metabolic networks are a striking example of bow-tie organization, an architecture able to input a wide range of nutrients and produce a large variety of products and complex macromolecules using a relatively few intermediate common currencies. A major technological application of this information is metabolic engineering. Here, organisms such as yeast, plants or bacteria are genetically modified to make them more useful in red biotechnology and aid the production of drugs such as antibiotics or industrial chemicals such as 1,3-propanediol and shikimic acid. These genetic modifications usually aim to reduce the amount of energy used to produce the product, increase yields and reduce the production of wastes.
Owing to the rapid decline in the populations of the animals that produce it, the importation and sale of ivory in many countries is banned or severely restricted. In the ten years preceding a decision in 1989 by CITES to ban international trade in African elephant ivory, the population of African elephants declined from 1.3 million to around 600,000. It was found by investigators from the Environmental Investigation Agency (EIA) that CITES sales of stockpiles from Singapore and Burundi (270 tonnes and 89.5 tonnes respectively) had created a system that increased the value of ivory on the international market, thus rewarding international smugglers and giving them the ability to control the trade and continue smuggling new ivory. Since the ivory ban, some Southern African countries have claimed their elephant populations are stable or increasing, and argued that ivory sales would support their conservation efforts. Other African countries oppose this position, stating that renewed ivory trading puts their own elephant populations under greater threat from poachers reacting to demand. CITES allowed the sale of 49 tonnes of ivory from Zimbabwe, Namibia and Botswana in 1997 to Japan. In 2007, under pressure from the International Fund for Animal Welfare, eBay banned all international sales of elephant-ivory products. The decision came after several mass slaughters of African elephants, most notably the 2006 Zakouma elephant slaughter in Chad.
Sources: en.wikipedia.org
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.
Lyophilized powder is usually kept frozen and protected from moisture. Solutions are less stable and are often used promptly or divided into aliquots to avoid repeated freeze-thaw cycles. Exact shelf-life values depend on purity and handling.
No. A purity figure derived from chromatographic area does not prove the amino acid sequence. Identity requires an orthogonal method such as mass spectrometry or sequencing. Truncated or isomerized peptides can co-elute with the target compound.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.