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.
Last reviewed on 2026-05-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
β1-blockers have fewer metabolic side effects in diabetic patients; however, the fast heart rate that serves as a warning sign for insulin-induced low blood sugar may be masked, resulting in hypoglycemia unawareness. This is termed beta blocker-induced hypoglycemia unawareness. Therefore, beta blockers are to be used cautiously in diabetics. A 2007 study revealed diuretics and beta blockers used for hypertension increase a patient's risk of developing diabetes mellitus, while ACE inhibitors and angiotensin II receptor antagonists (angiotensin receptor blockers) actually decrease the risk of diabetes. Clinical guidelines in Great Britain, but not in the United States, call for avoiding diuretics and beta blockers as first-line treatment of hypertension due to the risk of diabetes. Beta blockers must not be used in the treatment of selective alpha-adrenergic agonist overdose. The blockade of only beta receptors increases blood pressure, reduces coronary blood flow, left ventricular function, and cardiac output and tissue perfusion by means of leaving the alpha-adrenergic system stimulation unopposed. Beta blockers with lipophilic properties and CNS penetration such as metoprolol and labetalol may be useful for treating CNS and cardiovascular toxicity from a methamphetamine overdose. The mixed alpha- and beta blocker labetalol is especially useful for treatment of concomitant tachycardia and hypertension induced by methamphetamine. The phenomenon of "unopposed alpha stimulation" has not been reported with the use of beta blockers for treatment of methamphetamine toxicity.
== Stereocenters == Taxifolin has two stereocenters on the C-ring, as opposed to quercetin which has none. For example, (+)-taxifolin has (2R,3R)-configuration, making it one out of four stereoisomers that comprise two pairs of enantiomers.
Obesity is a risk factor for certain conditions, including diabetes, cancer, cardiovascular disease, high blood pressure, and non-alcoholic fatty liver disease. Reduction of obesity lowers those risks. A 1 kilogram (2.2 lb) loss of body weight has been associated with an approximate 1 millimetre of mercury (0.13 kPa) drop in blood pressure. Intentional weight loss is associated with cognitive performance improvements in overweight and obese individuals.
== Research == Trazodone may be effective in the treatment of sexual dysfunction, for instance female sexual dysfunction and erectile dysfunction. A 2003 systematic review and meta-analysis found some indication that trazodone may be useful in the treatment of erectile dysfunction. Besides trazodone alone, a combination of trazodone and bupropion (developmental code names and tentative brand names S1P-104, S1P-205, Lorexys, and Orexa) is under development for the treatment of erectile dysfunction and female sexual dysfunction. As of September 2021, it is in phase 2 clinical trials for these indications. It has been in this stage of clinical development since at least February 2015. Trazodone may be useful in the treatment of certain symptoms like sleep disturbances in alcohol withdrawal and recovery. However, reviews have recommended against use of trazodone for alcohol withdrawal due to inadequate evidence. Very limited evidence suggests that trazodone might be useful in the treatment of certain symptoms in cocaine use disorder. Trazodone has been reported to be effective in the treatment of sleep apnea. Cochrane reviews found that trazodone was not effective in the treatment of agitation in dementia. Another Cochrane review found that trazodone might be useful in the treatment of sleep disturbances in dementia. Further systematic reviews have found that trazodone may be effective for behavioral and psychological symptoms in dementias such as frontotemporal dementia and Alzheimer's disease.
=== Latin America and Caribbean === Gustavo Petro, President of Colombia, initially suggested that any attack on Venezuela would equate to an attack on Latin America and the Caribbean, and thus Colombia's armed forces could support Venezuela; he later moderated his position. On 23 September, he addressed the UN General Assembly to call for a "criminal process" to be opened against Donald Trump for US strikes in the Caribbean. Colombia convened an extraordinary virtual meeting of the Community of Latin American and Caribbean States in September 2025, which concluded with an expression of "deep concern" over foreign intervention in the region. Over Guatemala's objection that procedures were not followed, the group issued a statement saying the region must remain a "Zone of Peace" based on "... the prohibition of the threat or use of force, the peaceful settlement of disputes, the promotion of dialogue and multilateralism, unrestricted respect for sovereignty and territorial integrity, non-interference in the internal affairs of States, and the inalienable right of peoples to self-determination." Guatemala's president Bernardo Arévalo said Guatemala was included in the list of 21 countries (of the 33 members) approving the text, although it did not sign, nor did Ecuador, Peru, Costa Rica, and El Salvador. In August, when the initial three ships were deployed, Prime Minister of Trinidad and Tobago Kamla Persad-Bissessar offered the US military access to her nation for the US to protect Guyana amid the Guyana–Venezuela crisis.
Sources: en.wikipedia.org
== Military == MASS (decoy system), a naval defence system M26 Modular Accessory Shotgun System (or MASS), a developmental shotgun for the M16 rifle/M4 carbine family of guns MASS, Marine Air Support Squadrons within the United States Marine Corps
=== 20th century === The oldest United States–based think tank, the Carnegie Endowment for International Peace, was founded in Washington, D.C., in 1910 by philanthropist Andrew Carnegie. Carnegie charged trustees to use the fund to "hasten the abolition of international war, the foulest blot upon our civilization." The Brookings Institution was founded shortly thereafter in 1916 by Robert S. Brookings and was conceived as a bipartisan "research center modeled on academic institutions and focused on addressing the questions of the federal government." After 1945, the number of policy institutes increased, with many small new ones forming to address Cold War geopolitics and post-war reconstruction, aiming to express various issues and policy agendas. Until the 1940s, most think tanks were known only by the name of the institution. During the Second World War, think tanks were often referred to as "brain boxes". Before the 1950s, the phrase "think tank" did not refer to organizations. From its first appearances in the 1890s up to the 1950s, the phrase was most commonly used in American English to colloquially refer to the braincase or especially in a pejorative context to the human brain itself when commenting on an individual's failings (in the sense that something was wrong with that person's "think tank"). Around 1958, the first organization to be regularly described in published writings as "the Think Tank" (note the title case and the use of the definite article) was the Center for Advanced Study in the Behavioral Sciences.
In addition, a Black Hawk helicopter leased to the National Police by the U.S. was shot down, reportedly in the Bajo Cauca region, with some reports claiming it occurred in the Amalfi municipality. Later, in 2026, the U.S Department of State issued a $5,000,000USD Reward for Justice notice for information leading to the capture and arrest of individuals associated with the shootdown of the Black Hawk that occurred August 21, 2025. The notice also implied that Alexander Diaz Mendoza, a leader of a FARC-EP front the EMBF, was implicated in the attack due to his claim of responsibility published by El Espectador. Alexander Diaz was later reported to be killed in an armed clash with the Colombian Army in San Andrés de Cuerquia, on September 13, 2026. On 25 April, 2026, a bomb exploded on the Pan-American Highway in the municipality of Cajibío, killing 20 people and injuring 36. On April 28, police arrested José Vitonco, an alleged guerrilla leader, with connections to FARC leader Iván Mordisco.
==== Overall genital system structure ==== The genital system of an adult male P. phalangioides is located in the ventral portion of the opisthosoma and can be characterized by a large pair of testes and thin, twisted vasa deferentia which become thicker upon nearing the genital opening of the male pedipalp. These vasa deferentia distally fuse creating the ductus ejaculatorius of the spider. The ductus ejaculatorius is composed of lumen which contains large quantities of spermatozoa and other secretions. This variety of secretions is not seen in subadult males whose lumen only contains dense secretion matrix. Ventrally surrounding specific portions of the genital tract are apullate silk glands, and overall, the genital system is bordered by parts of the midgut gland. All stages of spermatogenesis are apparent in the adult testes, and the spermatozoa are coiled. In order to reach this stage with a fully formed male genital system, P. phalangioides must first go through two subadult phases.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.