Everything below concerns nootropic. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
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 |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
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.
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.
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.
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.
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.
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.
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.
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.
There were no reports of cross-border operations from either of the ethnic militant groups, although Iran had engaged in attacks against both of them, reportedly killing both Kurdish fighters of the Coalition of Political Forces of Iranian Kurdistan and Baloch fighters of the People's Fighters Front originating from outside Iran. Analysis of satellite images by The Washington Post revealed damage to at least 228 structures or pieces of equipment at US bases across the Persian Gulf, far more than the Trump administration has admitted to. On 1 March, six US soldiers were killed amid more than 30 injured in an Iranian drone attack near Camp Arifjan in Port Shuaiba, Kuwait. Those killed were soldiers of the United States Army Reserve assigned to the 103rd Expeditionary Sustainment Command, headquartered in Des Moines, Iowa. On 8 March, CENTCOM reported that a National Guard soldier died during a medical emergency. A soldier of the 1st Space Brigade was wounded in an attack against Prince Sultan Air Base on 1 March and died from his injuries on 9 March. According to a May report by the Congressional Research Service, 42 U.S. military aircraft were destroyed or damaged during the Iran-U.S. conflict. Data from the Center for Strategic and International Studies (CSIS) indicates that about 65 percent of the 2,330 US Patriot interceptor missiles available at the beginning of the conflict with Iran were used between February and July, leaving less than 850 missiles remaining.
Vegetable-tanned leather is tanned using tannins extracted from vegetable matter, such as tree bark prepared in bark mills. It is the oldest known method. It is supple and light brown in color, with the exact shade depending on the mix of materials and the color of the skin. The color tan derives its name from the appearance of undyed vegetable-tanned leather. Vegetable-tanned leather is not stable in water; it tends to discolor, and if left to soak and then dry, it shrinks and becomes harder, a feature of vegetable-tanned leather that is exploited in traditional shoemaking. In hot water, it shrinks drastically and partly congeals, becoming rigid and eventually brittle. Boiled leather is an example of this, where the leather has been hardened by being immersed in boiling water, or in wax or similar substances. Historically, it was occasionally used as armor after hardening, and it has also been used for book binding. Chrome-tanned leather is tanned using chromium sulfate and other chromium salts. It is also known as "wet blue" for the pale blue color of the undyed leather. The chrome tanning method usually takes approximately one day to complete, making it best suited for large-scale industrial use. This is the most common method in modern use. It is more supple and pliable than vegetable-tanned leather and does not discolor or lose shape as drastically in water as vegetable-tanned.
He presented the mechanism of the β-lactam development with proton sponge as the stoichiometric base, and also discussed the kinetic analysis of the catalyzed reaction of alkenes with α-imino esters. Lectka has studied the transition-metal catalyzed amide isomerization and peptide folding. He presented the first spectroscopic and crystallographic proof of copper(II)-sodium coordination in tertiary amides and discussed the role of side chain in substituted prolines as a binding site for copper. Lectka's research during his term at Johns Hopkins University also focused on enantioselective halogenation, cooperative asymmetric catalysis, the medicinal chemistry of fluorinated molecules, and studies on asymmetric catalysis on sequentially-linked columns leading to synthesis machines. He conducted research on the chemistry of [C-F-C] fluoronium ions and later reported first spectroscopic evidence for fluoronium ions in a solution. Lectka has also worked on metal-catalyzed aliphatic fluorination and site-selective aliphatic fluorination. Lectka has also established the use of fluorine as a through-space activating substituent for aromatic substitution.
The affinity, given as the dissociation constant (Kd), between a TCR and a pMHC was determined by surface plasmon resonance (SPR) to be in the range of 1–100 μM, with an association rate (kon) of 1000 -10000 M−1 s−1 and a dissociation rate (koff) of 0.01 -0.1 s−1. In comparison, cytokines have an affinity of KD = 10–600 pM to their receptor. It has been shown that even a single amino acid change in the presented peptide that affects the affinity of the pMHC to the TCR reduces the T-cell response and cannot be compensated by a higher pMHC concentration. A negative correlation between the dissociation rate of the pMHC-TCR complex and the strength of the T-cell response has been observed. That means, pMHC that bind the TCR for a longer time initiate a stronger activation of the T cell. Furthermore, T cells are highly sensitive; interaction with a single pMHC is enough to trigger activation. T cells move on quickly from antigens that do not trigger responses, rapidly scanning pMHC on an antigen-presenting cell (APC) to increase the chance of finding a specific pMHC. On average, a T cell encounters 20 APCs per hour. Different models for the molecular mechanisms that underlie this highly specific and highly sensitive process of antigen discrimination have been proposed. The occupational model simply suggests that the TCR response is proportional to the number of pMHC bound to the receptor. Given this model, a shorter lifetime of a peptide can be compensated by higher concentration such that the maximum response of the T cell stays the same.
The human brain contains multiple regions, as does the spinal cord. There are multiple ways to divide the brain, including by the embryological development of the brain; into three parts: the cerebellum, brainstem, and cerebrum; the evolution of the brain; and cytoarchitecture, as in the case of Brodmann areas. A popular model of the 'triune brain' — comprising the reptilian complex (basal ganglia), the paleomammalian complex (limbic system), and the neomammalian complex (neocortex) — was formerly popular during the 1960s, though is now regarded as a myth. 'Limbic system' and associated terms, however, remain in neuroanatomical use, although some neuroscientists have argued against such use.
Sources: en.wikipedia.org
==== Music ==== MDMA and ecstasy have featured in a number of songs, including Miley Cyrus's "We Can't Stop", Jay-Z and Alicia Keys' "Empire State of Mind", Fujiya & Miyagi's "Seratonin Rushes", Soulwax's "E Talking", Nonpoint's "Double Stacked", Green Velvet's "La La Land", Primal Scream's "Don't Fight It, Feel It", The Streets' "Blinded by the Lights", The Shamen's "Ebeneezer Goode", Missy Elliott's "4 My People", Pulp's "Sorted for E's & Wizz" and Hot Chip's "Over and Over".
Olivia Thirlby as Cassandra Anderson:A rookie Judge and genetic mutant with powerful psychic abilities. Anderson can sense the thoughts and emotions of others. Thirlby contrasted her character with Dredd's "black and white" perspective, describing Anderson as existing "in a grey area where everything is enhanced or clouded by the fact [that] she knows what is going on in the very interior of a person". She undertook weapons and combat training, learning to perform a roundhouse kick to make her believably physically commanding. The character was partially inspired by singer Debbie Harry. Lena Headey as Madeline "Ma-Ma" Madrigal: A former prostitute turned drug lord and criminal kingpin who is the sole supplier of "Slo-Mo", a new and addictive drug. Headey's performance was inspired by punk-rock singer Patti Smith. Reich described the character as someone who does "not care at all about what anybody thinks or feels and she will do, and behave, as she wants". Headey said: "I think of [Ma-Ma] like an old great white shark who is just waiting for someone bigger and stronger to show up and kill her ... she's ready for it. In fact, she can't wait for it to happen ... She's an addict, so she's dead in that way, but that last knock just hasn't come." Before Headey's casting, the character was envisioned as a heavily made-up, scarred and obese older woman. Wood Harris as Kay: Ma-Ma's clansman. Harris described the character as a villain, but one that sees himself as no worse than the Judges. Harris said: " ...
== External links == Comparison of difference versions of GLP (Comparison OECD, FDA and EPA GLP) Code of Federal Regulations Title 21 (Food and Drugs) Part 58 (Good Laboratory Practice for Nonclinical Laboratory Studies) (USA) Good Laboratory Practice (Organisation for Economic Co-operation and Development) OECD Series on Principles of Good Laboratory Practice and Compliance Monitoring Belgian Monitoring Authority for GLP Archived 2019-09-10 at the Wayback Machine TECHNOXMART Archived 2019-12-23 at the Wayback Machine
== Gene expression == The proglucagon gene is expressed in several organs, including the pancreas (α-cells of the islets of Langerhans), gut (intestinal enteroendocrine L-cells) and brain (caudal brainstem and hypothalamus). Pancreatic proglucagon gene expression is promoted upon fasting and hypoglycaemia induction and inhibited by insulin. Conversely, intestinal proglucagon gene expression is reduced during fasting and stimulated upon food consumption. In mammals, the transcription gives rise to identical mRNA in all three cell types, which is further translated to the 180 amino acid precursor called proglucagon. However, as a result of tissue-specific posttranslational processing mechanisms, different peptides are produced in the different cells. In the pancreas (α-cells of the islets of Langerhans), proglucagon is cleaved by prohormone convertase (PC) 2 producing glicentin-related pancreatic peptide (GRPP), glucagon, intervening peptide-1 (IP-1) and major proglucagon fragment (MPGF). In the gut and brain, proglucagon is catalysed by PC 1/3 giving rise to glicentin, which may be further processed to GRPP and oxyntomodulin, GLP-1, intervening peptide-2 (IP-2) and glucagon-like peptide-2 (GLP-2). Initially, GLP-1 was thought to correspond to proglucagon (72–108) suitable with the N-terminal of the MPGF, but sequencing experiments of endogenous GLP-1 revealed a structure corresponding to proglucagon (78–107) from which two discoveries were found. Firstly, the full-length GLP-1 (1–37) was found to be catalysed by endopeptidase to the biologically active GLP-1 (7–37).
The study concluded that Tyrannosaurus had the relatively largest brain of all adult non-avian dinosaurs with the exception of certain small maniraptoriforms (Bambiraptor, Troodon and Ornithomimus). The study found that Tyrannosaurus's relative brain size was still within the range of modern reptiles, being at most 2 standard deviations above the mean of non-avian reptile EQs. The estimates for the ratio of cerebrum mass to brain mass would range from 47.5 to 49.53 percent. According to the study, this is more than the lowest estimates for extant birds (44.6 percent), but still close to the typical ratios of the smallest sexually mature alligators which range from 45.9 to 47.9 percent. Other studies, such as those by Steve Brusatte, indicate the encephalization quotient of Tyrannosaurus was similar in range (2.0–2.4) to a chimpanzee (2.2–2.5), though this may be debatable as reptilian and mammalian encephalization quotients are not equivalent.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.