A practical reference on Tuftsin analogue: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-06 and is reviewed periodically as new material appears.
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.
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.
| 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 |
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
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.
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.
== Synthesis == The synthesis (in this case, of carbon-14-labelled material) can be seen in figure 1. In the first step, o-nitroaniline (compound 1) is purified through dissolution in hot water-ethanol mixture in relation 2:1. [Activated carbon] is added and the result is filtrated for clarifying. The filtrate is chilled while kept in movement to generate crystals, usually at 4 °C, but if needed it can also be cooled to −10 °C. The crystals are then collected, washed and dried. If it is pure enough it is used for the following steps, which take place at 0 till 5 °C. To produce o-Nitrobenzonitrile-14C (compound 2), the first component o-nitroaniline and (concentrated reagent grade) hydrochloric acid are put together with ice and water. Sodium nitrite, dissolved in water, is added to this thin slurry. After the formation of a pale-yellow solution, which indicates the completion of the diazotization reaction, the pH should be adjusted to 6. After this, the solution is introduced to a mixture of cuprous cyanide and toluene. At room temperature the toluene layer is removed. The aqueous layer is washed and dried and the purified product is isolated by crystallization. The third product is Anthranilamide-14C (compound 3). It is formed out of o-Nitrobenzonitrile-14C, which is first solved in ethanol and hydrazine hydrate. The solvent is heated subsequently, treated in a well-ventilated hood with small periodic charges, smaller than 10 mg, of Raney nickel. Under nitrogen atmosphere the ethanolic solution is clarified and dried.
When endothelial damage exposes the underlying extracellular matrix, adhesion begins in which von Willebrand factor binds to collagen, causing the recruitment of platelets through interactions with glycoprotein Ib receptors. This initial attachment allows platelets to stick to the damaged vessel wall. Upon adhesion, platelets undergo morphological changes and release bioactive molecules from their granules—signifying activation. Molecules like ADP and thromboxane A₂ increase the activation signal, which calls more circulating platelets to the injury site. Activation also leads to the expression of phosphatidylserine on the membrane surface. This acts as a catalytic platform for the coagulation cascade. Lastly, aggregation is performed as activated platelets express glycoprotein IIb/IIIa receptors, which bind fibrinogen and facilitate platelet-platelet interactions. This, in turn, leads to clot formation and stabilization and reinforces the platelet plug by converting fibrinogen into an insoluble fibrin mesh. Platelets also have a key role in immune responses, inflammation, and tissue repair through their interactions with leukocytes and endothelial cells. To recruit immune cells to injury sites, activated platelets can release cytokines and chemokines such as platelet factor 4 (PF4) and transforming growth factor-beta (TGF-β). They also form platelet-leukocyte aggregates, which further enhance neutrophil and monocyte activation, in turn supporting pathogen clearance and inflammatory signaling.
This included Meskigal, as governor of the city-state of Adab and Karsum governor of the unlocated Niqqum (suggested to be modern Khanaqin). Another was Lugal-ushumgal of Lagash. Several inscriptions of Lugal-ushumgal, who went on to serve the successor of Naram-Sin, Shar-Kali-Sharri, are known, particularly seal impressions, which refer to him as governor of Lagash and at the time a vassal (𒀵, arad, "servant" or "slave") of Naram-Sin.
=== Regional === The West Yorkshire Combined Authority is a strategic authority established in 2014. It allows the five metropolitan borough councils to collaborate. The authority was restructured in 2021 to be led by a directly elected mayor, the Mayor of West Yorkshire, and at the same time gained additional powers over areas including education, housing, and planning. The current mayor is Tracy Brabin, who was first elected in 2021 and successfully defended her seat in 2024. As part of the establishment of the combined authority, the West Yorkshire Passenger Transport Executive was abolished and its functions transferred to the new authority.
Sources: en.wikipedia.org
==== Injection ==== Subjective effects not commonly shared with other methods of administration include a ringing in the ears moments after injection (usually when over 120 milligrams) lasting 2 to 5 minutes including tinnitus and audio distortion. This is colloquially referred to as a "bell ringer". In a study of cocaine users, the average time taken to reach peak subjective effects was 3.1 minutes. The euphoria passes quickly. Aside from the toxic effects of cocaine, there is also the danger of circulatory emboli from the insoluble substances that may be used to cut the drug. As with all injected illicit substances, there is a risk of the user contracting blood-borne infections if sterile injecting equipment is not available or used.
Humans and also carry many interferon pseudogenes, including the entire nu family (IFNNΨ), an ortholog of IFNW1 (IFNWXΨ), a singular delta pseudogene (IFNDΨ), and a few members of the alpha and omega families. Many of these loci are also pseudogenes in other mammals. Consult the HGNC website for a full list of officially named genes and pseudogenes.
In contrast to pregabalin, food does not significantly affect the Tmax of gabapentin and increases the Cmax of gabapentin by approximately 10%. The Tmax of the instant-release (IR) formulation of gabapentin enacarbil (as active gabapentin) is about 2.1 to 2.6 hours across all doses (350–2,800 mg) with single administration and 1.6 to 1.9 hours across all doses (350–2,100 mg) with repeated administration. Conversely, the Tmax of the extended-release (XR) formulation of gabapentin enacarbil is about 5.1 hours at a single dose of 1,200 mg in a fasted state and 8.4 hours at a single dose of 1,200 mg in a fed state. The Tmax of phenibut has not been reported, but the onset of action and peak effects have been described as occurring at 2 to 4 hours and 5 to 6 hours, respectively, after oral ingestion in recreational users taking high doses (1–3 g).
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.
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.