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 2026-06-02. 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.
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.
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.
| 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 |
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
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.
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.
Both faiths give a prominent place to Jesus: Jesus is the central figure of Christianity, and in the Druze faith, Jesus is considered an important prophet of God, being among the seven prophets who appeared in different periods of history.
Jung identified two primary 'attitudinal types'—introvert and extrovert. While the terms 'introversion' and 'extraversion' had prior use in European thought, Jung was the first to integrate them into a comprehensive structural theory of personality. He redefined these concepts not merely as social traits, but as fundamental directions of psychic energy (libido), establishing the first systematic model of psychological types based on the movement of psychic energy libido toward the subject or the object. In Psychological Types, Jung defined the primary attitudinal types (introvert and extrovert), comparing them to the ancient archetypes: Apollo and Dionysus. The introvert is likened to Apollo, who shines a light on understanding. The introvert is focused on the internal world of reflection, dreaming, and vision. Thoughtful and insightful, the introvert can sometimes be uninterested in joining the activities of others. The introvert's libido flows inwards towards subjective factors and is influenced by 'inner necessity'. By contrast, the extravert is associated with Dionysus, interested in joining the activities of the world. The extravert is focused on the outside world of objects, sensory perception, and action. Energetic and lively, the extravert may lose their sense of self in the intoxication of Dionysian pursuits. For the extravert, the libido flows outwards, and the person has an interest, relationship and dependence on events, people and things. Jung's concepts of introversion and extraversion differ fundamentally from their common usage in modern trait psychology.
== Career == In 1898, she founded the Philadelphia Clinical Laboratory and conducted bacteriological analyses. She educated farmers on the handling of raw milk in order to improve the safety of ice cream sold at local schools. In the same year, she accepted a position with the Women's Medical College of Pennsylvania as director of their clinical laboratory. She also served as a research worker in the department of hygiene at the University of Pennsylvania from 1898 to 1901, and was a bacteriologist with the Philadelphia Bureau of Health. In her position with the Bureau of Health, she was instrumental in improving sanitation standards for the handling of milk and milk products.
==== Germany ==== DET is controlled in Germany under Anlage I BtMG (Narcotics Act, Schedule I). as of January 24, 1974. It is illegal to manufacture, possess, import, export, buy, sell, procure or dispense it without a license.
Sources: en.wikipedia.org
==== Belief propagation ==== In belief propagation for protein design, the algorithm exchanges messages that describe the belief that each residue has about the probability of each rotamer in neighboring residues. The algorithm updates messages on every iteration and iterates until convergence or until a fixed number of iterations. Convergence is not guaranteed in protein design. The message mi→ j(rj that a residue i sends to every rotamer (rj at neighboring residue j is defined as:
Another possibility is that the central opioid system may have low endogenous functionality in most individuals, becoming active only in the presence of exogenously administered opioid receptor agonists or with stimulation by endogenous opioids induced by pain or stress. A third possibility is that normal individuals may experience different side effects with naltrexone than people with addictive disease such as alcohol or opioid dependence, who may have altered opioid tone or responsiveness. It is notable in this regard that most studies of naltrexone have been in people with substance dependence. Naltrexone may also initially produce opioid withdrawal-like symptoms in a small subset of people not dependent on opioids:
=== Pharmacodynamics === Aticaprant is a potent, selective, short-acting (i.e., non-"inactivating") antagonist of the KOR (Ki = 0.81 nM vs. 24.0 nM and 155 nM for the μ-opioid receptor (MOR) and δ-opioid receptor (DOR), respectively; approximately 30-fold selectivity for the KOR). The drug has been found to dose-dependently block fentanyl-induced miosis at 25 mg and 60 mg in humans (with minimal to no blockade at doses of 4 to 10 mg), suggesting that the drug significantly occupies and antagonizes the MOR at a dose of at least 25 mg but not of 10 mg or less. However, a more recent study assessing neuroendocrine effects of the drug in normal volunteers and subjects with a history of cocaine dependence reported observations consistent with modest MOR antagonism at the 10 mg dose. In animal models of depression, aticaprant has been found to have potent synergistic efficacy in combination with other antidepressants such as citalopram and imipramine. Positron emission tomography imaging revealed that brain KORs were almost completely saturated by the drug 2.5 hours following a single dose of 10 mg, which supported the 4 mg to 25 mg dosages that aticaprant is being explored at in clinical trials. Occupancy was 35% for a 0.5 mg dose and 94% for a 10 mg dose. At 24 hours post-dose, receptor occupancy was 19% for 0.5 mg and 82% for 25 mg. No serious side effects were observed, and all side effects seen were mild to moderate and were not thought to be due to aticaprant.
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.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.