Everything below concerns peptide purity. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
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.
== Software Packages == Many chromatography software packages are provided by manufacturers, and many of them only provide a simple interface to acquire data. They also provide different tools to analyze this data. The following is a list of software and the (unexplained) tools that each provides. Please note that some of them were discontinued with the years.
=== Australia === The conservative Liberal–National Coalition issued a statement welcoming the news, with leader Sussan Ley remarking that "We should live in a world where dictators and despots face justice for their crimes." The Greens defense spokesman David Shoebridge condemned the operation as a breach of international law that "continues the world on a dangerous path of lawless aggression." Labor Against War, a political group within the ruling Labor Party, called on the government to condemn the strikes and to "immediately distance itself from the Trump administration, whose conduct is marked by [...] lawlessness at home and violent, reckless coercion abroad".
The Ba'athist government of Syria ruled by the Al-Assad family was known for its extensive involvement in drug trade since the 1970s. As of 2022, the Syrian government financed the biggest multi-billion dollar drug trade in the world, mostly focused on an illegal drug known as Captagon, making it the world's largest narco-state. Its revenues from Captagon smuggling alone were estimated at $57 billion annually in 2022, which is approximately thrice the total trade of all Mexican cartels. General Maher al-Assad, younger brother of Syrian dictator Bashar al-Assad and commander of the Fourth Armoured Division, directly supervised the production, smuggling and profiteering of the drug business. Already suffering from severe financial problems as a result of corruption and civil war, profits from Captagon were said to be the "lifeline" of the Assad regime, through which it earned more than 90% of its total revenue. The smugglers receive direct training from the Syrian military to successfully conduct trafficking operations. Republican Guard, commanded by Maher al-Assad was one of the main Ba'athist military divisions that was engaged in perpetrating brutal crackdowns and mass violence against protestors across the country. In 2018, Bashar al-Assad assigned Maher as the commander of the 4th Armoured Division, a military unit that supervised the Assad regime's criminal enterprises like smuggling, drug trafficking, narcotics production and plunder of goods and resources.
Sources: en.wikipedia.org
The therapeutic properties of alprazolam are similar to other benzodiazepines and include anxiolytic, anticonvulsant, muscle relaxant, hypnotic, and amnesic; however, it is used mainly as an anxiolytic. Giving alprazolam, as compared to lorazepam, has been demonstrated to elicit a statistically significant increase in extracellular dopamine D1 and D2 concentrations in the striatum.
The US National Academy of Medicine updated the Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for thiamine in 1998. The EARs for thiamine for women and men aged 14 and over are 0.9 mg/day and 1.1 mg/day, respectively; the RDAs are 1.1 and 1.2 mg/day, respectively. RDAs are higher than EARs to provide adequate intake levels for individuals with higher than average requirements. The RDA during pregnancy and for lactating females is 1.4 mg/day; a typical daily prenatal vitamin product contains around 1.5 mg of thiamine. For infants up to the age of 12 months, the Adequate Intake (AI) is 0.2–0.3 mg/day and for children aged 1–13 years the RDA increases with age from 0.5 to 0.9 mg/day. The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intakes (PRIs) instead of RDAs, and Average Requirements instead of EARs. For women (including those pregnant or lactating), men and children the PRI is 0.1 mg thiamine per megajoule (MJ) of energy in their diet. As the conversion is 1 MJ = 239 kcal, an adult consuming 2390 kilocalories ought to be consuming 1.0 mg thiamine. This is slightly lower than the US RDA. Neither the National Academy of Medicine nor EFSA have set an upper intake level for thiamine, as there is no human data for adverse effects from high doses.
Mutations in the OTC gene can cause Ornithine transcarbamylase deficiency. It is classified as a urea cycle disorder due to the fact that without proper OTC function ammonia starts to accumulate in the blood. Accumulation of ammonia in the blood is known as hyperammonemia. Although toxic in excess, ammonia is a nitrogen source for the body. Therefore increased ammonia will also increase levels of the nitrogen-containing non-essential amino acids glutamate, glutamine, and alanine. Levels of carbamoyl phosphate (CP) will begin to drop as urea nitrogen levels in the blood decrease. This will cause CP to be diverted to the uridine monophosphate synthetic pathway. Orotic acid is a product of this pathway. Increased levels of orotic acid in urine can be an indicator that a patient is suffering from a disorder linked to hyperammonemia. OTC deficiency manifests in both early and late onset forms.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.