Everything below concerns Peptide mapping. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-06. Numbers and descriptions here follow the published literature rather than marketing material.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
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.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
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.
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.
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.
== Use and effects == (R)-MDMA has a dose of 125 to 300 mg orally and a duration of 3.5 to 5.2 hours. It has been estimated that doses of 125 mg MDMA, 100 mg (S)-MDMA, and 300 mg (R)-MDMA are equivalent. The first modern clinical study of the comparative effects of MDMA, (R)-MDMA, and (S)-MDMA was published in August 2024. It compared 125 mg MDMA, 125 mg (S)-MDMA, 125 and 250 mg (R)-MDMA, and placebo. (R)-MDMA increased any drug effect, good drug effect, drug liking, stimulation, drug high, alteration of vision, and alteration of sense of time ratings similarly to MDMA and (S)-MDMA. However, (S)-MDMA 125 mg was more potent in increasing subjective effects, including stimulation, drug high, happy, and open, among others, than (R)-MDMA 125 or 250 mg or MDMA 125 mg. Ratings of bad drug effect and fear were minimal with MDMA, (R)-MDMA, and (S)-MDMA. In contrast to expectations, (R)-MDMA did not produce more psychedelic-like effects than (S)-MDMA. Besides subjective effects, (R)-MDMA increased heart rate, blood pressure, and body temperature similarly to MDMA and (S)-MDMA, though it was less potent in producing these effects. Body temperature was notably increased to the same extent with (R)-MDMA 250 mg as with MDMA 125 mg and (S)-MDMA 125 mg. The differences in effects between (R)-MDMA and (S)-MDMA may reflect the higher potency of (S)-MDMA rather than actual qualitative differences between the effects of (S)-MDMA and (R)-MDMA. It was estimated that equivalent effects would be expected with (S)-MDMA 100 mg, MDMA 125 mg, and (R)-MDMA 300 mg.
=== Non-IgG-like === There are other BsAbs that lack an Fc region entirely, and thus leads to relatively simple design strategies. These include chemically linked Fabs, consisting of only the Fab regions, and various types of bivalent and trivalent single-chain variable fragments (ScFvs). There are also fusion proteins mimicking the variable domains of two antibodies. The furthest developed of these newer formats are the bi-specific T-cell engagers (BiTEs), which uses the G4S linker to connect two ScFvs-one CD3 antibody ScFv and one tumor-associated antigen (TAA) or tumor-specific ScFv-to redirect T cells to cancer cells for target killing. Other platforms include tetravalent antiparallel structure (TandAbs) and VH only (Bi-Nanobody). The TandAb platform is formed by a tetravalent antibody molecule containing two binding sites for each of two antigens. In this platform, the reverse pairing of two peptide chains forms a homodimer molecule. As an example, AFM11 is based on the TandAbs platform and targets both CD3 and CD19 to achieve therapeutic effects. AFM11 showed dose-dependent inhibition of Raji tumors in vivo. The Bi-Nanobody platform forms multi-specific binding through the connection between the VH regions of two or more antibody molecules. The products that are designed based on this platform are small molecules and these small molecules have high stability and better tissue permeability in vivo. Even though non-IgG-like BsAbs have low molecular weight and thus high tumor tissue permeability, their half-life is relatively short and they require multiple doses.
=== Single-cell approach === There are attempts to provide partition coefficients for drugs at a single-cell level. This strategy requires methods for the determination of concentrations in individual cells, i.e., with Fluorescence correlation spectroscopy or quantitative Image analysis. Partition coefficient at a single-cell level provides information on cellular uptake mechanism.
Most children with progeria appear normal at birth and during early infancy. Children with progeria usually develop the first symptoms during their first few months of life. The earliest symptoms may include a failure to thrive and a localized scleroderma-like skin condition. As a child ages past infancy, additional conditions become apparent, usually around 18–24 months. Limited growth, full-body alopecia (hair loss), and a distinctive appearance (a small face with a shallow, recessed jaw and a pinched nose) are all characteristics of progeria. Signs and symptoms of this progressive disease tend to become more marked as the child ages. Later, the condition causes wrinkled skin, kidney failure, loss of eyesight, and atherosclerosis and other cardiovascular problems. Scleroderma, a hardening and tightening of the skin on trunk and extremities of the body, is prevalent. People diagnosed with this disorder usually have small, fragile bodies, like those of older adults. The head is usually large relative to the body, with a narrow, wrinkled face and a beak nose. Prominent scalp veins are noticeable (made more obvious by alopecia), as well as prominent eyes. Musculoskeletal degeneration causes loss of body fat and muscle, stiff joints, hip dislocations, and other symptoms generally absent in the non-elderly population. Individuals usually retain typical mental and motor function.
== Liquid chromatography == Back pressure is the term used for the hydraulic pressure required to create a flow through a chromatography column in high-performance liquid chromatography, the term deriving from the fact that it is generated by the resistance of the column, and exerts its influence backwards on the pump that must supply the flow. Back-pressure is a useful diagnostic feature of problems with the chromatography column. Rapid chromatography is favoured by columns packed with very small particles, which create high back-pressures. Column designers use "kinetic plots" to show the performance of a column at a constant back-pressure, usually selected as the maximum that a system's pump can reliably produce.
Sources: en.wikipedia.org
I am myself a Christian, a member of a community that preserves an ancient heritage of great literature and great music, provides help and counsel to young and old when they are in trouble, educates children in moral responsibility, and worships God in its own fashion. But I find Polkinghorne's theology altogether too narrow for my taste. I have no use for a theology that claims to know the answers to deep questions but bases its arguments on the beliefs of a single tribe. I am a practicing Christian but not a believing Christian. To me, to worship God means to recognize that mind and intelligence are woven into the fabric of our universe in a way that altogether surpasses our comprehension. Accepting the Templeton Prize, he said that
=== Investigations === Diabetic ketoacidosis may be diagnosed when the combination of hyperglycemia (high blood sugars), ketones in the blood or on urinalysis and acidosis are demonstrated. In about 10% of cases the blood sugar is not significantly elevated ("euglycemic diabetic ketoacidosis"). A pH measurement is performed to detect acidosis. Blood from a vein is adequate, as there is little difference between the arterial and the venous pH; arterial samples are only required if there are concerns about oxygen levels. Ketones can be measured in the urine (acetoacetate) and blood (β-hydroxybutyrate). When compared with urine acetoacetate testing, capillary blood β-hydroxybutyrate determination can reduce the need for admission, shorten the duration of hospital admission and potentially reduce the costs of hospital care. At very high levels, capillary blood ketone measurement becomes imprecise. In addition to the above, blood samples are usually taken to measure urea and creatinine (measures of kidney function, which may be impaired in DKA as a result of dehydration) and electrolytes. Furthermore, markers of infection (complete blood count, C-reactive protein) and acute pancreatitis (amylase and lipase) may be measured. Given the need to exclude infection, chest radiography and urinalysis are usually performed. If cerebral edema is suspected because of confusion, recurrent vomiting or other symptoms, computed tomography may be performed to assess its severity and to exclude other causes such as stroke.
The hormone vasopressin also stimulates the activity of NKCC2. Vasopressin stimulates sodium chloride reabsorption in the thick ascending limb of the nephron by activating signaling pathways. Vasopressin increases the traffic of NKCC2 to the membrane and phosphorylates some serine and threonine sites on the cytoplasmic N-terminal of the NKCC2 located in the membrane, increasing its activity. Increased NKCC2 activity aids in water reabsorption in the collecting duct through aquaporin 2 channels by creating a hypo-osmotic filtrate.
=== Other === During a G7 foreign ministers' meeting in Canada on 11 November 2025, the French foreign minister, Jean-Noël Barrot, criticized US military operations in the Caribbean, saying they violated international law and could contribute to regional instability. He was quoted as saying, "We have observed with concern the military operations in the Caribbean region, because they violate international law and because France has a presence in this region through its overseas territories, where more than a million of our compatriots reside," without citing specific US actions, and said that it was crucial to avoid "instability caused by potential escalations". Canadian officials distanced the Canadian military and intelligence personnel from the strikes. Sources speaking to CNN said that Canada did not want its intelligence used for the strikes but that it intended to continue its partnership with the Coast Guard under Operation Caribbe. A Department of National Defence spokesperson stated that "Canadian Armed Forces activities under Operation Caribbe, conducted in co-ordination with the United States Coast Guard, are separate and distinct", referencing the strikes on suspected drug boats. On 12 November, when foreign affairs minister, Anita Anand, was asked whether Canada was withholding intelligence from Washington on narcotics trafficking in Latin America, she responded: "The US has made it clear it is using its own intelligence.
==== Selected reaction monitoring ==== When employing selected reaction monitoring (SRM) or multiple reaction monitoring (MRM) modes, both Q1 and Q3 are set at a specific mass, allowing only a distinct fragment ion from a certain precursor ion to be detected. This method results in increased sensitivity. If Q1 and/or Q3 is set to more than a single mass, this configuration is called multiple reaction monitoring.
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
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.