The short version of Tuftsin fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-09 and is reviewed periodically as new material appears.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical 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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
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.
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.
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.
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.
The mostly studied system is yttrium (Y) fractionation between the phosphate monazite and the silicates garnet and xenotime. All three minerals preferentially fractionate Y, yet they form and break down at different stages of metamorphism. Xenotime has the highest fractionating power, then garnet and then monazite. In a simplified case of a clockwise P-T path involving garnet and monazite, garnet grows along a prograde path with Y continuously being incorporated, thus the Y content in monazite formed at this stage (prograde) should decrease progressively with higher grade. However, as temperature increases to a certain point, partial melting (anatectic) of monazite occurs around its rim, releasing Y into the melts. As the system later cools and melt crystallizes, regrown monazite will have higher Y content. Partial melting usually happens during peak metamorphism (the highest temperature in a P-T path), but age and chemical information during this stage are not recorded since the monazite is melting. However, the ages of last prograde growth rim (lowest Y) and the first post-anatectic growth rim (highest Y) usually bracket the time of partial melting. Another scenario involves the formation or breakdown of garnet, influencing the Y and HREE (heavy rare earth elements) content in the environment, thus the content of growing monazite. Basically, monazites grown before garnet formation have a higher Y and HREE content than those formed during or after garnet formation.
== Contraindications == Pentoxyverine is contraindicated in persons with bronchial asthma or other kinds of respiratory insufficiency (breathing difficulties), as well as angle-closure glaucoma. No data are available for the use of pentoxyverine during pregnancy, lactation, or children under two years of age, wherefore the drug must not be used under these circumstances. Antitussive drugs are not useful in patients with extensive phlegm production because they prevent coughing up the phlegm.
However, enobosarm did not successfully increase muscle strength in these phase 3 trials. In any case, it has been suggested that the study designs and physical function outcomes in such trials may have been flawed. The increases in lean body mass that have been seen with employed doses of enobosarm in clinical trials are very modest compared to those produced with supraphysiological doses of testosterone over similar timeframes (e.g., 0.5–1.5 kg with enobosarm versus 5–8 kg with 300–600 mg/week intramuscular testosterone enanthate in healthy young men). The effects of higher doses of enobosarm (9–18 mg/day) on lean body mass and muscle strength are also being evaluated in women with breast cancer. There is some evidence that women may be more sensitive to lean body mass increases with SARMs, specifically GSK-2881078 but potentially also others like enobosarm, than men. In addition to its mixed agonist–antagonist activity at the AR, enobosarm is likely to also differ from steroidal androgens in its effects due to differences in within-tissue ligand metabolism. The virilizing and androgenic effects of the traditional steroidal androgens like testosterone in skin, hair follicles, and the prostate gland are attributed to high expression of 5α-reductase in these tissues and consequent local conversion and potentiation into more potent androgens. In the case of testosterone, this is via conversion into the 10-fold more potent androgen DHT.
==== Iron import ==== Most cell types take up iron primarily through receptor-mediated endocytosis via transferrin receptor 1 (TFR1), transferrin receptor 2 (TFR2) and GAPDH. TFR1 has a 30-fold higher affinity for transferrin-bound iron than TFR2 and thus is the main player in this process. The higher order multifunctional glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) also acts as a transferrin receptor. Transferrin-bound ferric iron is recognized by these transferrin receptors, triggering a conformational change that causes endocytosis. Iron then enters the cytoplasm from the endosome via importer DMT1 after being reduced to its ferrous state by a STEAP family reductase. Alternatively, iron can enter the cell directly via plasma membrane divalent cation importers such as DMT1 and ZIP14 (Zrt-Irt-like protein 14). Again, iron enters the cytoplasm in the ferrous state after being reduced in the extracellular space by a reductase such as STEAP2, STEAP3 (in red blood cells), Dcytb (in enterocytes) and SDR2.
Sources: en.wikipedia.org
=== Skin === The rheumatoid nodule, which is sometimes in the skin, is the most common non-joint feature and occurs in 30% of people who have RA. It is a type of inflammatory reaction known as a "necrotizing granuloma". The initial pathologic process in nodule formation is unknown but may be essentially the same as the synovitis, since similar structural features occur in both. The nodule has a central area of fibrinoid necrosis that may be fissured and which corresponds to the fibrin-rich necrotic material found in and around an affected synovial space. Surrounding the necrosis is a layer of palisading macrophages and fibroblasts, corresponding to the intimal layer in synovium and a cuff of connective tissue containing clusters of lymphocytes and plasma cells, corresponding to the subintimal zone in synovitis. The typical rheumatoid nodule may be a few millimetres to a few centimetres in diameter and is usually found over bony prominences, such as the elbow, the heel, the knuckles, or other areas that sustain repeated mechanical stress. Nodules are associated with a positive RF (rheumatoid factor) titer, ACPA, and severe erosive arthritis. Rarely, these can occur in internal organs or at diverse sites on the body. Several forms of vasculitis occur in RA, but are mostly seen with long-standing and untreated disease. The most common presentation is due to involvement of small- and medium-sized vessels. Rheumatoid vasculitis can thus commonly present with skin ulceration and vasculitic nerve infarction known as mononeuritis multiplex.
=== Dog domestication === Since the domestication of dogs, they have evolved alongside humans due to pressure from humans and the environment. This began by humans and wolves sharing the same area, with a pressure to coexist eventually leading to their domestication. Evolutionary pressure from humans led to many different breeds that paralleled the needs of the time, whether it was a need for protecting livestock or assisting in the hunt. Hunting and herding were a couple of the first reasons for humans artificially selecting for traits they deemed beneficial. This selective breeding does not stop there, but extends to humans selecting for certain traits deemed desirable in their domesticated dogs, such as size and color, even if they are not necessarily beneficial to the human in a tangible way. An unintended consequence of this selection is that domesticated dogs also tend to have heritable diseases depending on what specific breed they encompass.
== Function == The primary function of muscle is contraction. Following contraction, skeletal muscle functions as an endocrine organ by secreting myokines – a wide range of cytokines and other peptides that act as signalling molecules. Myokines in turn are believed to mediate the health benefits of exercise. Myokines are secreted into the bloodstream after muscle contraction. Interleukin 6 (IL-6) is the most studied myokine, other muscle contraction-induced myokines include BDNF, FGF21, and SPARC. Muscle also functions to produce body heat. Muscle contraction is responsible for producing 85% of the body's heat. This heat produced is as a by-product of muscular activity, and is mostly wasted. As a homeostatic response to extreme cold, muscles are signaled to trigger contractions of shivering in order to generate heat.
==== APCI MS ==== The source for APCI is similar to ESI except that ions are formed by the interaction of the heated analyte solvent with a corona discharge needle set at a high electrical potential. Primary ions are formed immediately surrounding the needle, and these interact with the solvent to form secondary ions that ultimately ionize the sample. APCI is particularly useful for the analysis of nonpolar lipids such as triacylglycerols, sterols, and fatty acid esters.
The Austrian public radio station Ö1 Kulturmagazin drew parallels to Kermani's earlier works, noting that its comparative religious metaphysics were also influenced by the question of theodicy. Kermani received the Joseph Breitbach Prize in 2014 for his book Dein Name [Your Name]. and the Thomas Mann Prize in 2024 for his novel Das Alphabet bis S [The Alphabet up to S], which in form and content is a sequel to Dein Name. Advocating for the ideological neutrality of the state Kermani nevertheless criticizes "religious illiteracy" associated with the "complete suppression of religion", which he says leads to a "fundamental spiritual impoverishment of society". Identifying religious tolerance and freedom of religion as important European values, Kermani emphatically calls for the consideration of the beliefs and worldviews of others in the spirit of the Enlightenment. No human being can uncover the ultimate mysteries such as why something exists rather than nothing. According to Kermani, that is why religion came into being in the first place: in it, humans find ways of dealing with what they cannot explain. Religion, then, does not run contrary to the Enlightenment; rather, religion gives expression to what transcends human reason. Kermani notes that precisely to ignore the limits of human reason is what actually constitutes a more anti-Enlightenment stance.
Sources: en.wikipedia.org
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.