tuftsin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
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.
| 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 |
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
=== Gm–Gu === Leopold Gmelin (1788–1853), German chemist who discovered potassium ferricyanide; author of Handbook of Chemistry, which is still used Theodore Nicolas Gobley (1811–1874), French chemist, pioneer in brain tissues analysis, discoverer of lecithin Sulamith Goldhaber (1923–1965), Austrian-American chemist, high-energy physicist, and molecular spectroscopist Victor Goldschmidt (1888–1947), Norwegian mineralogist considered to be one of the founders of modern geochemistry Moses Gomberg (1866–1947), Russian-American chemist, known for pioneering work in radical chemistry Mary L. Good (1931–2019), American inorganic chemist who studied catalysis by ruthenium David van Goorle also called Gorlaeus (1591–1612), Dutch chemist, one of the first modern atomists, who thought that all bodies are made up of atoms Loney Gordon (1915–1999), American chemist who assisted in creating the pertussis vaccine Carl Gräbe (1841–1927), German chemist who synthesized the dye alizarin Thomas Graham (1805–1869), Scottish chemist known for pioneering work on dialysis and diffusion of gases Harry B. Gray (born 1935), American chemist known for the kinetics of long-range electron-transfer reactions in metalloproteins; 2004 Wolf Prize in Chemistry Martha Greenblatt (born 1941), American solid state inorganic chemist, 2003 American Chemical Society's Garvan-Olin Medal Bettye Washington Greene (1935–1995), American industrial chemist who studied colloid and latex chemistry, including interactions between latex and paper Sandra C.
Brown fat or brown adipose tissue (BAT) is a specialized form of adipose tissue important for adaptive thermogenesis in humans and other mammals. BAT can generate heat by "uncoupling" the respiratory chain of oxidative phosphorylation within mitochondria through tissue-specific expression of uncoupling protein 1 (UCP1). BAT is primarily located around the neck and large blood vessels of the thorax, where it may effectively act in heat exchange. BAT is robustly activated upon cold exposure by the release of catecholamines from sympathetic nerves that results in UCP1 activation. Nearly half of the nerves present in adipose tissue are sensory neurons connected to the dorsal root ganglia. BAT activation may also occur in response to overfeeding. UCP1 activity is stimulated by long chain fatty acids that are produced subsequent to β-adrenergic receptor activation. UCP1 is proposed to function as a fatty acid proton symporter, although the exact mechanism has yet to be elucidated. In contrast, UCP1 is inhibited by ATP, ADP, and GTP. Attempts to simulate this process pharmacologically have so far been unsuccessful. Techniques to manipulate the differentiation of "brown fat" could become a mechanism for weight loss therapy in the future, encouraging the growth of tissue with this specialized metabolism without inducing it in other organs. A review on the eventual therapeutic targeting of brown fat to treat human obesity was published by Samuelson and Vidal-Puig in 2020.
=== Environmental Pollution === Other than medical and biological applications, microfluidics has been used for pollution detection and control. Although microfluidics is exclusively used for micron-sized particles, a novel lab-on-a-chip that integrates nano-sized particle aggregation with spiral inertial microfluidics for rapid detection of nanoplastics and very small microplastics from the environment.
Xi has formulated the new concept for development, stressing the importance of high-quality development rather than "inflated growth". He has stated China has abandoned a growth-at-all-costs strategy which Xi refers to as "GDP heroism". Instead, Xi said other social issues such as environmental protection are important. Xi has made eradicating extreme poverty through targeted poverty alleviation a key goal. In 2015, he launched the battle against poverty. The campaign concluded by 2021, when Xi declared a "complete victory" over extreme poverty, saying nearly 100 million have been lifted out of poverty under his tenure, though some experts said China's poverty threshold was lower than that of the World Bank. In 2020, premier Li Keqiang, citing the National Bureau of Statistics (NBS) said that China still had 600 million people living with less than 1000 yuan ($140) a month, although The Economist said the methodology NBS used was flawed. When Xi took office in 2012, 58% of people in China were living on less than $8.30 per day, in 2022 this had fallen to 21%. At the 19th Party Congress in 2017, Xi stated the primary contradiction of China's conditions in the new era as "the contradiction between the people's ever-growing need for a better life and unbalanced and inadequate development." In this context, "unbalanced" refers to rural-urban inequalities, regional inequalities, inequalities between the rich and poor, and structural imbalances in the economy. "Inadequate" refers to household income share.
Sources: en.wikipedia.org
== Pharmacokinetics == When comparing the pharmacokinetic properties of spironolactone and eplerenone, it is clear that the two drugs differ. Spironolactone has shorter half-life (t1/2 = 1.3-1.4 hours) than eplerenone (t1/2 = 4–6 hours). Eplerenone goes through rapid metabolism by the liver to inactive metabolites (t1/2 = 4–6 hours). However, spironolactone is metabolized to three active metabolites, which give it prolonged activity (13.8 – 16. 5 hours). Spironolactone has a long half-life and is excreted 47-51% through kidneys. Patients with chronic kidney disease therefore require close monitoring when taking the drug. Spironolactone is also eliminated through feces (35-41%). The excretion of eplerenone is 67% through kidneys and 32% through feces. The information about excretion plays a critical role when determining the appropriate doses for patients with renal and/or hepatic dysfunction. It is very important to adjust the doses for patients with renal dysfunction because if they fail to eliminate the drug through their kidneys it could accumulate in the body, causing high concentration of potassium in the blood.
== Books == Skeletal Muscle Research: Cellular Physiology & Biochemistry (ed. with M. J. Kankaanpää) (1993) Skeletal Muscle Research: Metabolism & Pathophysiology (ed. with L. Packer and O. Hänninen) (1994) Exercise and Oxygen Toxicity (ed. with M. Atalay) (1994) Oxidative Stress In Skeletal Muscles (ed. with Reznick, A et al.) (1998) Antioxidant and Redox Regulation of Genes. 2000. doi:10.1016/B978-0-12-636670-9.X5000-4. ISBN 978-0-12-636670-9. Handbook of Oxidants & Antioxidants in Exercise (ed. with L. Packer and O. Hänninen) (2000) Methods in Enzymology: Redox Cell Biology & Genetics - Parts A and B (ed. with L. Packer) (2002) Methods in Enzymology: Oxygen Sensing (ed. with G. L. Semenza) (2004) Advances in Wound Care - Volume 1 (2010) Advances in Wound Care - Volume 2 (2011) Nutrition and Enhanced Sports Performances (ed. with Bagchi D. and Nair S.) (2013) MicroRNA in Regenerative Medicine. 2015. doi:10.1016/C2012-0-02839-6. ISBN 978-0-12-405544-5.
== Excess == Elevated HbA2 levels that surpass 3.5%, indicate a potential mutation in the beta-globin genes. This potential mutation typically occurs in the -87 and -88 promoter region, which affects the proximal CACCC box. Another factor leading to increased HbA2 levels involves the deletion of bases that are placed adjacent to the beta-globin genes. This deletion results in a heightened HbA2 levels due to removing the locus control regions in the beta promoter. This specific promoter is crucial for gene interactions with both gamma and beta globin genes, which also enables both genes to be expressed.
Ethanol is most commonly ingested by mouth, but other routes of administration are possible, such as inhalation, enema, or by intravenous injection. With oral administration, the ethanol is absorbed into the portal venous blood through the mucosa of the gastrointestinal tract, such as in the oral cavity, stomach, duodenum, and jejunum. The oral bioavailability of ethanol is quite high, with estimates ranging from 80% at a minimum to 94–96%. The ethanol molecule is small and uncharged, and easily crosses biological membranes by passive diffusion. The absorption rate of ethanol is typically modeled as a first-order kinetic process depending on the concentration gradient and specific membrane. The rate of absorption is fastest in the duodenum and jejunum, owing to the larger absorption surface area provided by the villi and microvilli of the small intestines. Gastric emptying is therefore an important consideration when estimating the overall rate of absorption in most scenarios; the presence of a meal in the stomach delays gastric emptying, and absorption of ethanol into the blood is consequently slower. Due to irregular gastric emptying patterns, the rate of absorption of ethanol is unpredictable, varying significantly even between drinking occasions. In experiments, aqueous ethanol solutions have been given intravenously or rectally to avoid this variation. The delay in ethanol absorption caused by food is similar regardless of whether food is consumed just before, at the same time, or just after ingestion of ethanol.
=== 15 January === At least 120 people were killed in an RSF attack on a civilian convoy being escorted by the Sudan Liberation Movement (SLM) and the Gathering of Sudan Liberation Forces (GSLF) near Kabkabiya, North Darfur. Nine people were killed in attacks by the SAF and the RSF on members of the Kanabi community, who mostly originate from Darfur, in Abu Gouta, Gezira State. Fifteen people were killed in an RSF attack on the village of Al-Khizan in Abu Gouta. The Sultan Ali Dinar Palace Museum in El Fasher was shelled by the RSF, causing a fire that heavily damaged the structure and destroyed its contents and furniture.
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 seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.