If you have been reading about heptapeptide 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 2026-06-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
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.
These kinases consist of extracellular domains, a transmembrane spanning alpha helix, and an intracellular tyrosine kinase domain protruding into the cytoplasm. They play important roles in regulating cell division, cellular differentiation, and morphogenesis. More than 50 receptor tyrosine kinases are known in mammals.
Lawsone (2-hydroxy-1,4-naphthoquinone), also known as hennotannic acid, is a red-orange dye present in the leaves of the henna plant (Lawsonia inermis), for which it is named, as well as in the common walnut (Juglans regia) and water hyacinth (Pontederia crassipes). Humans have used henna extracts containing lawsone as hair and skin dyes for more than 5,000 years. Lawsone reacts chemically with the protein keratin in skin and hair via a Michael addition reaction, resulting in a strong permanent stain that lasts until the skin or hair is shed. Darker colored staining is due to more lawsone–keratin interactions occurring, which evidently break down as the concentration of lawsone decreases and the tattoo fades. Lawsone strongly absorbs UV light, and aqueous extracts can be effective sunless tanning agents and sunscreens. Lawsone is a 1,4-naphthoquinone derivative, an analog of hydroxyquinone containing one additional ring. Lawsone isolation from Lawsonia inermis can be difficult due to its easily biodegradable nature. Isolation involves four steps:
Michael Bailey, who found that homosexuality had a genetic possibility; Laura Allen and Roger Gorski of UCLA had conducted research on the anterior commissure; molecular geneticist Cassandra Smith; the editor of The Arizona Republic. Directed by Jeremy Taylor, produced by Oliver Morse, made by Windfall Films 18 October Antichaos, about order out of chaos, with Ian Stewart of the University of Warwick; Canadian mathematician Brian Goodwin of the Open University, and emergence; the American biologist Stuart Kauffman of the Santa Fe Institute, and Boolean networks; the Danish theoretical physicist Per Bak of Brookhaven National Laboratory; Christopher Langton of the Santa Fe Institute; the American ecologist Tom Ray of the University of Delaware; the economist W. Brian Arthur of Stanford University; J. Doyne Farmer of the Prediction Company; and the American physicist Thomas Valone (a writer on bioelectromagnetics) of the University of New Mexico. Narrated by Alun Lewis, directed by Yavar Abbas, produced by Geoff Deehan, made by Union Pictures 25 October The Strange Case of Crop Circles 2, showing what had changed from the previous documentary broadcast on 27 October 1991. Directed by Jill Freeman, produced by Michael Wills, made by Juniper Productions 1 November Zen on Wheels, about how Japanese car manufacturers moved a team to Newport Beach, California at the Toyota Calty Design Research, to find out what appealed to buyers of BMW and Mercedes cars, which resulted in the Lexus LS, which outsold Mercedes-Benz and BMW.
Chem. Int. Ed. 2017, 56, 16018-16022. https://doi.org/10.1002/anie.201709463. M, Hifsudheen.; R, K, Mishra.; B, Vedhanarayanan.; V, K, Praveen.; and Ajayaghosh, Ayyappanpillai (2017). “Helix to Super-Helix Transition in p-Systems Self-assembly: Superseding of Molecular Chirality at Hierarchical Level”. Angew. Chem., Int. Ed. 2017, 56, 12634-12638. https://doi.org/10.1002/anie.201707392. S, Ghosh.; S, Cherumukkil.; C, H, Suresh.; and Ajayaghosh, Ayyappanpillai (2017). “A Supramolecular Nanocomposite as Near Infrared Transmitting Optical Filter for Security and Forensic Applications”. Adv. Mater. 2017, 29, 1703783.doi:10.1002/adma.201703783 A, Mal.; R, K, Mishra.; V, K, Praveen.; M, A, Khayum.; R, Banerjee.; and Ajayaghosh, Ayyappanpillai (2018). “Supramolecular Reassembly of Self-Exfoliated Ionic Covalent Organic Nanosheets for Label-Free Detection of dsDNA”. Angew. Chem., Int. Ed. 2018, 57, 8443. https://doi.org/10.1002/anie.201801352. R, D, Mukhopadhyay.; G, Das.; and Ajayaghosh, Ayyappanpillai (2018). “Stepwise Control of Host-Guest Interaction Using a Coordination Polymer Gel”. Nat. Commun. 2018, 9, 1987. https://doi.org/10.1038/s41467-018-04303-8. V, K, Praveen.; B, Vedhanarayanan.; A, Mal.; R, K, Mishra.; and Ajayaghosh Ayyappanpillai (2020). “Self-Assembled Extended p‑Systems for Sensing and Security Applications”. Acc. Chem. Res. 2020, 53, 2, 496-507. https://doi.org/10.1021/acs.accounts.9b00580 S, Chakraborty.; M, M, Joseph.; S, Varughese.; S, Ghosh.; K, K, Maiti.; A, Samanta.; and Ajayaghosh, Ayyappanpillai (2020).
=== Type 2 diabetes === There are contradictory reviews. From one, vitamin C supplementation cannot be recommended for management of type 2 diabetes. However, another reported that supplementation with high doses of vitamin C can decrease blood glucose, insulin and hemoglobin A1c.
Sources: en.wikipedia.org
In 2013 for the population aged 40-80 years, the global prevalence of glaucoma was estimated at 3.54%, thus affecting 64.3 million worldwide. The same year, 2.97 million people in North America had open-angle glaucoma. By 2040, the prevalence of all types of glaucoma was projected to increase to 111.82 million worldwide and to 4.72 million in North America. Globally, glaucoma is the second-leading cause of blindness, while cataracts are a more common cause. In the United States, glaucoma is a leading cause of blindness for African Americans, who have higher rates of primary open-angle glaucoma, and Hispanic Americans. Bilateral vision loss can negatively affect mobility and interfere with driving. A meta-analysis published in 2009 found that people with primary open-angle glaucoma do not have increased mortality rates or increased risk of cardiovascular death. A 2024 JAMA Ophthalmology article reports that in 2022, an estimated 4.22 million people in the U.S. had glaucoma, with 1.49 million experiencing vision impairment due to the condition, according to a meta-analysis. The study found that Black adults were about twice as likely to be affected by glaucoma as White adults. Glaucoma prevalence was 1.62% among individuals aged 18 and older and 2.56% among those aged 40 and older, while vision-affecting glaucoma occurred in 0.57% and 0.91% of these age groups, respectively.
{\displaystyle {\begin{cases}{\ce {^{244}_{96}Cm ->[{\ce {(\alpha,n)}}] ^{247}_{98}Cf ->[\epsilon][3.11 \ {\ce {h}}] ^{247}_{97}Bk}}\\{\ce {^{244}_{96}Cm ->[{\ce {(\alpha,p)}}] ^{247}_{97}Bk}}\end{cases}}}
==== Dangers ==== If taken undiluted by mouth, GBL can cause esophageal and gastro-intestinal irritation. It is possible for oral ingestion of GBL to cause nausea and other similar problems, possibly more so than with GHB. GHB has biphasic effects, a euphoric effect at low doses (the reason for the term liquid ecstasy), and a sedative effect at higher doses. As a result of this sedation it can cause unconsciousness. When combined with alcohol the increased sedation and risk of vomiting results in a high risk of fatality. As a result, many harm reduction organizations suggest never mixing the two drugs. There have been several news reports of deaths associated with GBL, usually in combination with alcohol or other depressants.
==== Pilosan research ==== Casali et al. (2026) identify a poorly developed dental alveolus in a specimen of Nothrotherium maquinense from the Pleistocene strata from Brazil, occupying the position of caniniform alveolus in Neogene nothrotheriids, and interpreted as a possible case of partial re-expression of a lost ancestral dental condition in the studied individual. Revision of nematheriine scelidotheriid sloths from the Miocene Santa Cruz Formation (Argentina) is published by Boscaini et al. (2026), who assign all studied fossils to the genus Nematherium, with the majority of them assigned to the species N. angulatum New fossil material of Ocnotherium giganteum, including a nearly complete skull and two partial skeletons, is described from the Pleistocene strata from Brazil by Pujos et al. (2026), who recover O. giganteum as a mylodontine mylodontid. Evidence from the study of a mylodontid coprolite from the Pleistocene strata from the Cueva Cacao 1.A site (Argentina) indicative of a grazing-browsing dietary niche of the producer is presented by Velázquez et al. (2026). Zicos et al. (2026) compare the utility of three ancient DNA extraction methods for recovery of DNA from coprolites of Mylodon darwinii and soil samples from Cueva del Milodón (Chile), and report recovery of both sloth mitochondrial genomes and signatures of local flora. Harper et al.
Sources: en.wikipedia.org
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
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.