If you have been reading about anxiolytic 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 |
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.
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.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
n C4H4NH + 2n FeCl3 → (C4H2NH)n + 2n FeCl2 + 2n HCl The process is thought to occur via the formation of the pi-radical cation C4H4NH+. This electrophile attacks the C-2 carbon of an unoxidized molecule of pyrrole to give a dimeric cation [(C4H4NH)2]2+. The process repeats itself many times. Conductive forms of PPy are prepared by oxidation ("p-doping") of the polymer:
The talks concluded on 12 April 2026. The negotiations lasted about 21 hours and ended with the United States and Iranian delegations leaving Islamabad without reaching a deal. The main unresolved issues reportedly included Iran's nuclear program and the status of the Strait of Hormuz. Other issues included sanctions relief and frozen assets. While the US side insisted on a phased relief linked to compliance, Iran demanded comprehensive lifting of sanctions and release of assets, including $6 billion in frozen assets, as a precondition to a meaningful deal. Iranian officials said they had not expected an agreement to be reached in a single round of talks and that contacts were expected to continue. Pakistani officials described the talks as part of an effort to preserve the ceasefire and encourage further diplomacy between the parties. Iran's minister of foreign affairs Abbas Araghchi claimed that they were "inches away from an MoU" and accused the US delegation of moving the goalposts and maximalizing. More broadly, the Iranian delegation believed that Washington had to do more to earn their trust. According to an analysis in Iran International, Iran's diplomacy following the failure of the talks has been to express defiance towards American pressure while leaving the possibility of future diplomacy still open. Trump claimed that Iran had "knowingly failed" to reopen the Strait of Hormuz, and Vance said that Iran had refused the possibility of not developing nuclear weapons.
=== Limitations === The wound must be of a type that can benefit from the application of maggot therapy. A moist, exudating wound with sufficient oxygen supply is a prerequisite. Not all wound-types are suitable: wounds which are dry, or open wounds of body cavities do not provide a good environment for maggots to feed. In some cases it may be possible to make a dry wound suitable for larval therapy by moistening it with saline soaks. Patients and doctors may find maggots distasteful, although studies have shown that this does not cause patients to refuse the offer of maggot therapy. Maggots can be enclosed in opaque polymer bags to hide them from sight. Dressings must be designed to prevent any maggots from escaping, while allowing air to get to the maggots. Dressings are also designed to minimize the uncomfortable tickling sensation that the maggots often cause.
Sources: en.wikipedia.org
As ETD is increasingly popular for protein and peptide structure analysis, implementation on easily available ion-trap mass spectrometers coupled with high resolution mass analyzers continues to evolve.
Mary Osborn and Klaus Weber wrote a classic paper in biochemistry on determination of the molecular weight of a protein via SDS polyacrylamide gel electrophoresis, published in 1969 in Journal of Biological Chemistry. They knew that in 1967 Shapiro, Vinuela, and Maisel had shown that electrophoresis of proteins along with Sodium Dodecyl Sulfate (SDS) in polyacrylamide gels (PAGE) could separate the tested polypeptide chains by molecular weight. To see if this method applied to proteins of various sizes and shapes, Osborn and Weber took 40 known proteins, including globular and filamentous proteins, analyzed them via SDS PAGE, and plotted the logarithms of their molecular weights against their electrophoretic mobilities. The results showed convincingly that "the good resolution and the fact that an estimate of the molecular weight can be obtained within a day, together with the small amount of protein needed, makes the method strongly competitive with others commonly employed." This method has been used extensively by biochemists in all kinds of studies involving protein purification and identification as part of the process.
=== Psychological profile === Prior to the trial, the court ordered further psychological assessment for Agüero. The evaluating professionals determined that Agüero has a "self-centered personality", and that she seeks "recognition, power, and admiration", plus "lack of empathy and affection, with expressions of satisfaction from close contact with another person's suffering". The mental health professionals also found that Agüero has traits of a dissociative personality disorder, with one side of her personality being completely aware of reality, while the other side denies said reality and compensates for it with the production of her wishes. The same professionals stated that these traits are "typical mechanisms of a psychopathic personality". During the trial, further testimony was presented by mental health professionals. Psychologist Martínez Goyena said that Agüero does not suffer from any active mental health disorder, and that she is capable of understanding reality. Further analysis showed narcissistic, self-referential, and psychopathic traits. Defense psychiatrist Quiroga said, in contrast, that there are no previous indicators that Agüero could have psychopathic features in her personality. Multiple mental health professionals testified on 18 February that Agüero seeks "visibility" for her crimes, as well as repeating pre-trial examination findings that she lacks empathy, citing the total reluctance by Agüero to acknowledge the suffering of the families of the murdered babies.
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.
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.