If you have been reading about GABA-A receptor 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 2026-07-16. 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.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
| 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 |
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.
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.
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.
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.
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.
=== Disadvantages === Reduced immunogenicity compared to attenuated vaccines Require adjuvants to improve immunogenicity Often require multiple doses ("booster" doses) to provide long-term immunity Can be difficult to isolate the specific antigen(s) which will invoke the necessary immune response It is not easy to supervise conjugation chemistry which leads to noncontinuous variation
The party's nominee in 2012 and 2016, Stein is a physician and a former member of the Lexington Town Meeting. On August 16, Stein selected academic Butch Ware as her running mate. Stein achieved ballot access in 38 states, and was eligible to receive write-in votes in seven states. She was not eligible to receive write-in votes in the remaining states or the District of Columbia.
The two substrates of this enzyme are 3-hydroxyisobutyric acid and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are methylmalonic acid semialdehyde, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 3-hydroxy-2-methylpropanoate:NAD+ oxidoreductase. This enzyme participates in valine, leucine and isoleucine degradation.
The pericardial cavity (surrounding the heart), pleural cavity (surrounding the lungs) and peritoneal cavity (surrounding most organs of the abdomen) are the three serous cavities within the human body. While serous membranes have a lubricative role to play in all three cavities, in the pleural cavity it has a greater role to play in the function of breathing. The serous cavities are formed from the intraembryonic coelom and are basically an empty space within the body surrounded by serous membrane. Early in embryonic life visceral organs develop adjacent to a cavity and invaginate into the bag-like coelom. Therefore, each organ becomes surrounded by serous membrane - they do not lie within the serous cavity. The layer in contact with the organ is known as the visceral layer, while the parietal layer is in contact with the body wall.
=== Substrate binding === Creatine binds inside the β-half-barrel trough of the large C-terminal domain, forming hydrogen bonds between its amidino and carboxyl groups and the enzyme's amino-acid residues. A metal ion, either Zn2+ or Mn2+, is used to stabilize the substrate and polarize the amidino group.
Sources: en.wikipedia.org
As a mere graduate student, in 1972 Candace Pert discovered the brain’s opiate receptor – the cellular site where the body’s painkillers and "bliss-makers", the endorphins – bond with cells to weave their magic. Pert's discovery led to a revolution in neuroscience, helping open the door to the "information-based" model of the brain which is now replacing the old "structuralist" model... Molecules of Emotion begins as an eye-opener into the intellectual warfare of modern scientific discovery – the gamesmanship, the sly purloining of others' results – but also into the round-the-clock work, the exhilaration of a shared breakthrough, and the slow, painful rise of women in the scientific professions. The book concludes with the author integrating the science she pioneered with the holistic "energy medicines" which work on the same principles – till now without scientific rationales.
== Early life and education == Born in Dublin, the youngest son of Henry Horatio Dixon, he was interested in science from a young age; his discovery of an optical illusion arising from binocular vision was described by his father in Nature Magazine when he was only nine years old. After education at Shrewsbury School he was awarded a scholarship in 1946 to study Natural Sciences at King's College, Cambridge where his elder brother Kendal was a fellow, achieving firsts in Part I and Part II and specialising in biochemistry. He remained at King's for his graduate studies on peptide hormones, supervised by Frank Young, and was awarded a Ph.D. in 1954.
== Interactions == Concomitant or recent (previous 14 days) monoamine oxidase inhibitor (MAOI) use can lead to hypertensive reactions, including hypertensive crisis, and should be avoided. Clinical studies have found minimal or no influence of certain MAOIs like the weak non-selective MAOI linezolid and the potent selective MAO-B inhibitor selegiline (as a transdermal patch) on the pharmacokinetics of pseudoephedrine. This is in accordance with the fact that pseudoephedrine is not metabolized by monoamine oxidase (MAO). However, pseudoephedrine induces the release of norepinephrine, which MAOIs inhibit the metabolism of, and as such, MAOIs can still potentiate the effects of pseudoephedrine. No significant pharmacodynamic interactions have been found with selegiline, but linezolid potentiated blood pressure increases with pseudoephedrine. However, this was deemed to be without clinical significance in the case of linezolid, though it was noted that some individuals may be more sensitive to the sympathomimetic effects of pseudoephedrine and related agents. Pseudoephedrine is contraindicated with MAOIs like phenelzine, tranylcypromine, isocarboxazid, and moclobemide due to the potential for synergistic sympathomimetic effects and hypertensive crisis. It is also considered to be contraindicated with linezolid and selegiline as some individuals may react more sensitively to coadministration.
Dietary supplement companies aggressively promote NMN products claiming these benefits. NMN is a precursor to NAD+ biosynthesis, and dietary NMN supplementation has been shown to increase NAD+ concentrations and thus has the potential to mitigate aging-related disorders such as oxidative stress, DNA damage, neurodegeneration, and inflammatory responses. The potential benefits and risks of NMN supplementation as of 2023 are currently under study. Life extension Anti-aging movement
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.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.