If you have been reading about Research chemical and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-11-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The king brown snake (Pseudechis australis) or mulga snake is the largest species of venomous snake in Australia. The venom of this snake is relatively weak compared to many other Australian species. The LD50 is 2.38 mg/kg subcutaneous. However, these snakes can deliver large amounts of venom when they bite, compensating for the lower venom potency. Average venom yield is 180 mg and they have a maximum yield of 600 mg. The venom of this species contains potent myotoxins and anticoagulants, that can inhibit blood clotting. The neurotoxic components are weak. This snake can cause severe envenomation of humans. They are a moderately common cause of snakebites and uncommonly to rarely cause snakebite deaths in Australia at present. Envenomation can cause anticoagulation coagulopathy, kidney damage or kidney failure. They do not cause significant neurotoxic paralysis (muscle weakness, respiratory failure), though rarely they may cause ptosis (drooping of the upper eyelids). Bites can also cause myolysis (rhabdomyolysis, muscle damage) which can be very severe and is the major effect of bites. Rate of envenomation is 40–60%, while untreated mortality rate is 30–40%.
=== Early life === Major Force is a product of the same U.S. Federal project which created Captain Atom during the Vietnam War. The government, in a project headed by Wade Eiling and the scientist Megala, experiments with the effects of atomic energy on an alien metal to determine its full protective abilities such as protecting a human being from a nuclear blast. After Nathaniel Adam's disappearance and the perceived failure of the Captain Atom Project, the government restarts the project with a new test subject named Clifford Zmeck and increased the amount of metal used. While in the Air Force, Zmeck is imprisoned on charges of rape and murder and sentenced to life in prison. However, he is offered a pardon in exchange for participation in the high-risk governmental experiment. Zmeck disappears into the Quantum Field, emerging one year after the return of Nathaniel Adam with abilities similar to his.
Outside the cell, LTC4 can be converted by ubiquitous enzymes to form successively LTD4 and LTE4, which retain biological activity. The cysteinyl-leukotrienes act at their cell-surface receptors CysLT1 and CysLT2 on target cells to contract bronchial and vascular smooth muscle, to increase permeability of small blood vessels, to enhance secretion of mucus in the airway and gut, and to recruit leukocytes to sites of inflammation. Both LTB4 and the cysteinyl-leukotrienes (LTC4, LTD4, LTE4) are partly degraded in local tissues, and ultimately become inactive metabolites in the liver.
Also, this tail movement can increase the number interactions between the histone tail and the DNA, increasing likelihood of nucleosome formation and potentially leading to the creation of higher-order chromatin structure. In trans, P38 leads to the opposite effects: allowing for Set2 to methylate K36. Set2 is only affected by isomerization of P38 when creating a trimethylated K36 (commonly written as K36me3), however, and not K36me2. Fpr4 also binds to P32 in H4, though its effects are minimal. In mammalian cells, the isomerization of H3P30 interacts with the phosphorylation of H3S28 (serine in the 28 position of histone H3) and the methylation of H3K27. hFKBP25 is a PPIase that is a homolog for Fpr4 in mammalian cells and is found to commonly be associated with the presence of HDACs. Cyp33 is a cyclophilin that has the ability to isomerize H3 proline residues at P16 and P30 positions. Histones H2A and H2B also have multiple proline residues near amino acids that when modified affect the activity surrounding the histone.
Sources: en.wikipedia.org
== Pharmacodynamics == After being hydrolysed to epinine, ibopamine is able to stimulate the alpha-adrenergic and D1 dopaminergic receptors, thereby exhibiting mydriatic effects. In some randomized clinical trials, the D1 dopaminergic activity of ibopamine led to an increased production of aqueous humour and intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients.
In infants and adults, the excess β chains form unstable tetramers called hemoglobin H or HbH comprising 4 beta chains. In the fetus, the excess γ chains combine hemoglobin Bart's comprising 4 gamma chains Both HbH and Hb Bart's have a strong affinity for oxygen but do not release it, causing oxygen starvation in the tissues. They can also precipitate within the RBC damaging its membrane and shortening the life of the cell. The severity of the α-thalassemias is correlated with the number of affected α-globin alleles: the greater, the more severe will be the manifestations of the disease.
The first nonsteroidal androgens, the arylpropionamides, were discovered via structural modification of bicalutamide. Unlike bicalutamide (which is purely antiandrogenic), these compounds show tissue-selective androgenic effects and were classified as selective androgen receptor modulators (SARMs). Lead SARMs of this series included acetothiolutamide, enobosarm (ostarine; S-22), and andarine (acetamidoxolutamide or androxolutamide; S-4). They are very close to bicalutamide structurally, with the key differences being that the linker sulfone of bicalutamide has been replaced with an ether or thioether group to confer agonism of the AR and the 4-fluoro atom of the pertinent phenyl ring has been substituted with an acetamido or cyano group to eliminate reactivity at the position.
Trading with the Enemy Act of 1917 Foreign Assistance Act of 1961 International Emergency Economic Powers Act of 1977 Export Administration Act of 1979 Several laws specifically prohibit trade with certain countries:
=== Animal === Microchimerism occurs in most pairs of twins in cattle. In cattle (and other bovines), the placentas of fraternal twins usually fuse and the twins share blood circulation, resulting in exchange of cell lines. If the twins are a male–female pair, then XX/XY microchimerism results, and male hormones partially masculinize the heifer (female), creating a martin heifer or freemartin. Freemartins appear female, but are infertile and so cannot be used for breeding or dairy production. Microchimerism provides a method of diagnosing the condition, because male genetic material can be detected in a blood sample.
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.
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.