This is a working overview of nootropic, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-15 and is reviewed periodically as new material appears.
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.
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.
| 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 |
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
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.
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.
305200: type 5 130080: type 8 – unspecified gene, locus 12p13 225310: type 10 – unspecified gene, locus 2q34 608763: Beasley–Cohen type 130070: progeroid form – B4GALT7 130090: type unspecified 601776: D4ST1-deficient Ehlers–Danlos syndrome (adducted thumb-clubfoot syndrome) CHST14
== Plot summary == Willie Somerset Chandran is the son of a Brahmin father and a Dalit mother. His father gave him his middle name as a homage to the English writer Somerset Maugham who had visited the father in the temple where the father was living under a vow of silence. Having come to despise his father for giving him a split identity, Willie leaves India to go to 1950s London to study. There he leads a life as a different man with an interesting background 'oriental' and fakes the facts of his life. Later in London he writes a book of short stories and manages to publish it. Willie receives a letter from Ana, a mixed Portuguese and black African girl, who admires his book, and they arrange to meet. They fall in love and Willie follows her to her country (an unnamed Portuguese colony in Africa, presumably Mozambique). Meanwhile, Willie's sister Sarojini marries a German and moves to Berlin. The novel ends with Willie having moved to his sister's place in Berlin after his 18-year stay in Africa. Having discovered that he's been living other people's lives and mimicking their behaviours to hide his past, it is implied at the end that he drops the mask and comes to peace with his background. Half a Life is a prequel to Naipaul's 2004 novel Magic Seeds which starts with Willie in Berlin.
== Adverse effects == Ziprasidone (and all other second generation antipsychotics (SGAs)) received a boxed warning in the US due to increased mortality in elderly people with dementia-related psychosis. Sleepiness and headache are very common adverse effects (>10%). Common adverse effects (1–10%), include producing too much saliva or having dry mouth, runny nose, respiratory disorders or coughing, nausea and vomiting, stomach aches, constipation or diarrhea, loss of appetite, weight gain (but the smallest risk for weight gain compared to other antipsychotics), rashes, fast heart beats, blood pressure falling when standing up quickly, muscle pain, weakness, twitches, dizziness, and anxiety. Extrapyramidal symptoms are also common and include tremor, dystonia (sustained or repetitive muscle contractions), akathisia (the feeling of a need to be in motion), parkinsonism, and muscle rigidity; in a 2013 meta-analysis of 15 antipsychotic drugs, ziprasidone ranked 8th for such side effects. Ziprasidone is known to trigger mania in some bipolar patients. This medication can cause birth defects, according to animal studies, although this side effect has not been confirmed in humans. Recently, the FDA required the manufacturers of some atypical antipsychotics to include a warning about the risk of hyperglycemia and Type II diabetes with atypical antipsychotics. Some evidence suggests that ziprasidone does not cause insulin resistance to the degree of other atypical antipsychotics, such as olanzapine.
== Further reading == Noman, Ahmed; Shamsan, Mahmoud (23 August 2022). "Analysis: Origins of the Houthi supremacist ideology". commonspace.eu. Retrieved 3 July 2024. Sarhan, Mugahed; Saidin, Mohd Irwan Syazli (2022). "The Religious-Political Ideology of Houthis' Rebellion in Yemen: Theoretical Perspective of the Divine Right to Rule" (PDF). Archived from the original on 8 June 2025.
=== Adaptation strategies === Potato production is expected to decline in many areas due to hotter temperatures and decreased water availability. Conversely, production is predicted to become possible in high altitude and latitude areas where it has been limited by frost damage, such as in Canada and Russia. This will shift potato production to cooler areas, mitigating much of the projected decline in yield. However, this may trigger competition for land between potato crops and other land uses, mostly due to changes in water and temperature regimes. The other approach is through the development of varieties or cultivars which would be more adapted to altered conditions. This can be done through 'traditional' plant breeding techniques and genetic modification. These techniques allow for the selection of specific traits as a new cultivar is developed. Certain traits, such as heat stress tolerance, drought tolerance, fast growth/early maturation and disease resistance, may play an important role in creating new cultivars able to maintain yields under stressors induced by climate change. For instance, developing cultivars with greater heat stress tolerance would be critical for maintaining yields in countries with potato production areas near current cultivars' maximum temperature limits (e.g. Sub-Saharan Africa, India). Superior drought resistance can be achieved through improved water use efficiency (amount of food produced per amount of water used) or the ability to recover from short drought periods and still produce acceptable yields.
Sources: en.wikipedia.org
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP+, is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require it as a reducing agent ('hydrogen source'). NADPH is the reduced form, whereas NADP+ is the oxidized form. The reduced form, NADPH is used by all forms of cellular life as an electron donor as part of many biosynthetic reactions. NADP+ differs from NAD+ by the presence of an additional phosphate group on the 2' position of the ribose ring that carries the adenine moiety. This extra phosphate is added by NAD+ kinase and removed by NADP+ phosphatase. As cofactors for enzyme reactions in mammals, NAD+ and NADPH are typically the active forms (outside of oxidative phosphorylation). NAD+ participates in oxidative (and usually catabolic) reactions, while NADPH participates in reductive (and usually anabolic) reactions.
== Function == Endogenous production of these peptides stimulates cells in the skin such as fibroblasts to synthesise more of the connective tissue proteins, and is claimed that administering the synthetic equivalent peptides can facilitate skin repair and wound healing and may have an anti-wrinkle and anti-aging effect. These peptides are administered topically as skin creams, or sometimes by subcutaneous injection or microneedling. Due to the poor absorption of even small peptides when administered topically to the skin, it is common for them to be conjugated with lipophilic chains such as palmitate or myristate to help them penetrate more deeply, though modern skin cream formulations often use more advanced techniques such as encapsulating them within liposomes which can achieve a similar effect. Matrikines are a diverse class of signalling peptides which do not all have the same spectrum of activity; certain members of the family such as hexapeptide-12 actually have a primarily pro-aging effect and are used in research into the aging process rather than as ingredients of anti-aging skin creams. Other matrikines can have anti-aging effects at low concentrations but promote carcinogenesis and tumor growth at higher levels, so appropriate dosage control is critical.
== Software == Optimizing the application is more complex compared to 1D separations, as there are more parameters involved. Column flow and oven temperature program are both important when using either flow or thermal modulation. However, with thermal modulation, cold jet and hot jet pulse duration, length of the second dimension column and modulation time also affect the final results. In the case of flow modulation, the modulation time, split flow (for MS), loading flow, unloading flow, valve timings are crucial. The output is also different: the GC×GC technique produces a three-dimensional plot rather than a traditional chromatogram, facilitated by specially designed software packages. For example, GC Image was the first software developed for two dimensional gas chromatography. Some software packages are used in addition to the normal GC (or GC-MS) packages while others are built as a complete platform, controlling all aspects of the analysis. The new and different way of presenting and evaluating data offers additional information. For example, modern software can perform group-type separation as well as automated peak identification (with mass spectrometry).
The United States accused Maduro of electoral fraud and presiding over a "narco-state". In March 2020, during Trump's first term, the United States Justice Department indicted Maduro on cocaine-trafficking conspiracy charges, which Maduro denied. Trump designated two Venezuelan drug gangs, the Tren de Aragua and the Cartel of the Suns, as Foreign Terrorist Organizations (FTOs) in January and July 2025 respectively, and alleged that the latter was led by Maduro. Maduro denied being involved in cartel leadership and characterized the designations as an attempt to use the war on drugs for regime change. Some Latin American crime experts have described the Cartel of the Suns as more of a general network of Venezuelan government and military corruption than as an organized group. Also in July 2025, a secret order instructed the US military to use force against cartels listed as terrorist organizations. In August 2025, the reward for Maduro's arrest increased to $50 million with US attorney general Pam Bondi calling Maduro "one of the largest narco-traffickers in the world and a threat to our national security." However, the Associated Press reported in January 2026 that while the US government has never publicly accused Delcy Rodríguez of criminal wrongdoing related to the drug trade, the Drug Enforcement Administration has nonetheless gathered an extensive intelligence file on Rodríguez since 2018 and designated her as a "priority target" in 2022—which the agency does for individuals suspected of having "significant impact" on the drug trade.
Omics is the collective characterization and quantification of entire sets of biological molecules and the investigation of how they translate into the structure, function, and dynamics of an organism or group of organisms. The branches of science known informally as omics are various disciplines in biology whose names end in the suffix -omics, such as genomics, proteomics, metabolomics, metagenomics, phenomics and transcriptomics. The related suffix -ome is used to address the objects of study of such fields, such as the genome, proteome or metabolome respectively. The suffix -ome as used in molecular biology refers to a totality of some sort; it is an example of a "neo-suffix" formed by abstraction from various Greek terms in -ωμα, a sequence that does not form an identifiable suffix in Greek. Functional genomics aims at identifying the functions of as many genes as possible of a given organism. It combines different -omics techniques such as transcriptomics and proteomics with saturated mutant collections.
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.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.