Everything below concerns Selank. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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.
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 with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
Codeine became a prescription-only medication in the province of Manitoba on 1 February 2016. The number of low-dose codeine tablets sold in Manitoba decreased by 94 percent from 52.5 million tablets sold in the year prior to the policy change to 3.3 million in the year after. A pharmacist may issue a prescription, and all purchases are logged to a central database to prevent overprescribing. Saskatchewan's pharmacy college is considering enacting a similar ban to Manitoba's. On 9 May 2019, the Canadian Pharmacists Association wrote to Health Canada proposing regulations amending the NCR, the BOTSR, and the FDR - Part G, which included requiring that all products containing codeine be available by prescription only. New safety measures were issued by Health Canada on 28 July 2016; "codeine should no longer be used (contraindicated) in patients under 18 years of age to treat pain after surgery to remove tonsils or adenoids, as these patients are more susceptible to the risk of serious breathing problems. Codeine (prescription and non-prescription) is already not recommended for children under the age of 12, for any use."
== Chemistry == Selegiline is a substituted phenethylamine and amphetamine derivative. It is also known as (R)-(–)-N,α-dimethyl-N-(2-propynyl)phenethylamine, (R)-(–)-N-methyl-N-2-propynylamphetamine, or N-propargyl-L-methamphetamine. Selegiline (L-deprenyl) is the enantiopure levorotatory enantiomer of the racemic mixture deprenyl, whereas D-deprenyl is the dextrorotatory enantiomer. Selegiline is a derivative of levomethamphetamine (L-methamphetamine), the levorotatory enantiomer of the psychostimulant and sympathomimetic agent methamphetamine (N-methylamphetamine), with a propargyl group attached to the nitrogen atom of the molecule. Selegiline is a small-molecule compound, with the molecular formula C13H17N and a low molecular weight of 187.281 g/mol. It has high lipophilicity, with an experimental log P of 2.7 and predicted log P values of 2.9 to 3.1. Pharmaceutically, selegiline is used almost always as the hydrochloride salt, though the free base form has also been used. At room temperature, selegiline hydrochloride is a white to near white crystalline powder. Selegiline hydrochloride is freely soluble in water, chloroform, and methanol.
14 February – A study reviews educational content of 18,400 universities worldwide, finding higher education is not transitioning from fossil fuels to renewable energy curricula, failing to meet the growing demand for a clean energy workforce. On 26 February, a study analyzing funding sources and activities of two prominent academic centers delineates animal agriculture industry entrenchment in academia through support of industry-supported research and policy advocacy amid potential unfavorable policies.
berberine and oxyberberine caffeic acid ethyl ester isovanillin ferulic acid (+/-)-5,5'-dimethoxylariciresinol methyl beta-orsellinate obacunone limonin and 12alpha-hydroxylimonin nomilin γ-Fagarine canthin-6-one 4-methoxy-N-methyl-2-quinolone palmatine and oxypalmatine (+/-)-lyoniresinol β-sitosterol stigmasterine amurenlactone A amurenamide A phellodensins and phellodenols (2R)-sodium 3-phenyllactate jatrorrhizine an isocoumarin, 3-acetyl-3,4-dihydro-5,6-dimethoxy-1H-2-benzopyran-1-one Ala-Pro-Trp-Cys, a glutathione S-transferase activating peptide
Sources: en.wikipedia.org
== See also == Capillary electrophoresis–mass spectrometry Ion-mobility spectrometry–mass spectrometry Liquid chromatography–mass spectrometry Prolate trochoidal mass spectrometer Pyrolysis–gas chromatography–mass spectrometry
== Biography and education == Saladino earned a chemistry degree from the College of William and Mary, followed by 6 years spent traveling in North America and New Zealand. He later became a physician assistant and later did training in cardiology, gaining his MD from the University of Arizona in 2015, and completing his residency at the University of Washington in 2019. Saladino has board certification in psychiatry and is a certified "Functional Medicine" practitioner. As of 2022, his license to practice medicine in California was "delinquent" due to not paying fees.
A written description of a trial/study of any therapeutic, prophylactic, or diagnostic agent conducted in human subjects, in which the clinical and statistical description, presentations, and analyses are fully integrated into a single report. (ICH E6) Clinician
Cultivation is successful in climates with hot summers, with optimum growing conditions in mean temperatures of 20 to 30 °C (70 to 85 °F); temperatures of below 20 °C (70 °F) and over 40 °C (105 °F) stunt growth significantly. They can grow in a wide range of soils, with optimum growth in moist alluvial soils with good organic content. Soybeans, like most legumes, perform nitrogen fixation by establishing a symbiotic relationship with the bacterium Bradyrhizobium japonicum (syn. Rhizobium japonicum; Jordan 1982). This ability to fix nitrogen allows farmers to reduce nitrogen fertilizer use and increase yields when growing other crops in rotation with soy. There may be some trade-offs, however, in the long-term abundance of organic material in soils where soy and other crops (for example, corn) are grown in rotation. For best results, though, an inoculum of the correct strain of bacteria should be mixed with the soybean (or any legume) seed before planting. Modern crop cultivars generally reach a height of around 1 m (3 ft), and take 80–120 days from sowing to harvesting.
Headaches Enlargement of the hands, feet, nose, lips, and ears, and a general thickening of the skin Soft tissue swelling of internal organs, notably the heart with the attendant weakening of its muscularity, and the kidneys, also the vocal cords resulting in a characteristic thick, deep voice and slowing of speech Generalized expansion of the skull at the fontanelle Pronounced brow protrusion, often with ocular distension (frontal bossing) Pronounced lower jaw protrusion (prognathism) with attendant macroglossia (enlargement of the tongue) and teeth spacing Hypertrichosis, hyperpigmentation and hyperhidrosis Skin tags Carpal tunnel syndrome
Sources: en.wikipedia.org
A tetramer stain is a flow cytometry procedure that uses tetrameric proteins to detect and quantify T cells that are specific for a given antigen within a sample (e.g. blood, CSF). The tetramers used in the assay are made up of four major histocompatibility complex (MHC) molecules, which are found on the surface of most cells in the body. Cells produce MHC molecules containing peptides as a way to display the products those cells are making. One important function of MHC presentation is to communicate the presence of viruses, bacteria, cancerous mutations, or other antigens in a cell. If a T cell receptor recognises the peptide being presented by an MHC molecule, expansion of that T cell occurs. MHC tetramers are bioengineered to present a specific peptide that can be used to identify T cells with receptors that match that peptide. Tetramers are labeled with a fluorophore, allowing tetramer-bound T cells to be analyzed with flow cytometry. Quantification and sorting of T-cells by flow cytometry enables researchers to investigate immune response to e.g viral infection and vaccine administration as well as functionality of antigen-specific T cells. Generally, if a person's immune system has encountered a pathogen, the individual will possess T cells with specificity toward some peptide on that pathogen. If a tetramer stain specific for a pathogenic peptide (e.g. the Influenza virus A nucleoprotein (NP)) is positive, this indicates expansion of influenza A virus specific T cells in the subject.
=== Allergy diagnosis === Basophils are easily isolated from venous blood and present good "indicator cells" of an IgE-mediated allergic response based on the upregulation of activation markers such as CD63 and/or CD203c upon suspect allergen stimulation. Therefore, the BAT serves to confirm IgE-mediated allergy following uncertain results from classical testing based on anamnesis, skin testing or specific IgE results. More recently, BAT has also been used for the monitoring of successful allergen immunotherapy (desensitization) to differentiate short-term desensitization versus sustained unresponsiveness to the allergen.
==== Epigenetic factors ==== Methamphetamine addiction is persistent for many individuals, with 61% of individuals treated for addiction relapsing within one year. About half of those with methamphetamine addiction continue with use over a ten-year period, while the other half reduce use starting at about one to four years after initial use. The frequent persistence of addiction suggests that long-lasting changes in gene expression may occur in particular regions of the brain, and may contribute importantly to the addiction phenotype. In 2014, a crucial role was found for epigenetic mechanisms in driving lasting changes in gene expression in the brain. A review in 2015 summarized a number of studies involving chronic methamphetamine use in rodents. Epigenetic alterations were observed in the brain reward pathways, including areas like ventral tegmental area, nucleus accumbens, and dorsal striatum, the hippocampus, and the prefrontal cortex. Chronic methamphetamine use caused gene-specific histone acetylations, deacetylations and methylations. Gene-specific DNA methylations in particular regions of the brain were also observed. The various epigenetic alterations caused downregulations or upregulations of specific genes important in addiction. For instance, chronic methamphetamine use caused methylation of the lysine in position 4 of histone 3 located at the promoters of the c-fos and the C-C chemokine receptor 2 (ccr2) genes, activating those genes in the nucleus accumbens (NAc). c-fos is well known to be important in addiction.
13 October A grenade was thrown in the Vi Thanh District Chieu Hoi center, killing three civilians and wounding 46. The VC kidnapped a Catholic priest and a lay assistant, from the church at Phu Hoi, Biên Hòa Province.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.