Everything below concerns Enkephalinase. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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 |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
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.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
==== Housekeeping and waste disposal ==== When performing cleaning and decontaminating the work area where antineoplastic drugs are used, one should make sure that there is sufficient ventilation to prevent the buildup of airborne drug concentrations. When cleaning the work surface, hospital workers should use deactivation and cleaning agents before and after each activity as well as at the end of their shifts. Cleaning should always be done using double protective gloves and disposable gowns. After employees finish up cleaning, they should dispose of the items used in the activity in a yellow chemotherapy waste container while still wearing protective gloves. After removing the gloves, they should thoroughly wash their hands with soap and water. Anything that comes into contact or has a trace of the antineoplastic drugs, such as needles, empty vials, syringes, gowns, and gloves, should be put in the chemotherapy waste container.
Monoisotopic mass (Mmi) is one of several types of molecular masses used in mass spectrometry.The theoretical monoisotopic mass of a molecule is computed by taking the sum of the accurate masses (including mass defect) of the most abundant naturally occurring stable isotope of each atom in the molecule. It is also called the (theoretical) exact mass. This differs from the nominal molecular mass, which is the sum of the mass number of the primary isotope of each atom in the molecule and is an integer. It also is different from the molar mass or the average molecular weight, which uses the (abundance-weighted) average atomic masses. For small molecules made up of low-atomic-number elements, the monoisotopic mass is observable as a peak in a mass spectrum. For some atoms like carbon, oxygen, hydrogen, nitrogen, and sulfur, the Mmi of these elements is exactly the same as the mass of its lightest isotope. However, this does not hold true for all atoms. Iron's most common isotope has a mass number of 56, while the stable isotopes of iron vary in mass number from 54 to 58. Monoisotopic mass is typically expressed in daltons (Da).
=== Pharmacokinetics === Metabolism of myristicin yields 3-methoxycatechol and enzymatically forms 5-allyl-1-methoxy-2,3-dihydroxybenzene (oxidation of the methylenedioxy group). Myristicin is also transformed into demethylenylmyristicin, dihydroxymyristicin, and elemicin is transformed into O-demethylelemicin, O-demethyldihydroxyelemicin, and safrole. There has been speculation that myristicin might be converted into the psychedelic MMDA, but this has not been demonstrated in humans. However, two nitrogen-containing metabolites of myristicin have been identified in the urine of rats and guinea pigs following oral or intraperitoneal administration. The major basic ninhydrin-positive urinary metabolite of myristicin in the rat is 3-piperidyl-1-(3′methoxy-4′,5′-methylenedioxyphenyl)-1-propanone, while the major basic ninhydrin-positive urinary metabolite of the guinea pig is 3-pyrrolidinyl-1-(3′methoxy-4′,5′-methylenedioxyphenyl)-1-propanone. Equivalent nitrogen-containing metabolites have also been identified for safrole and elemicin, including the dimethylamine, piperidine and pyrrolidine forms. Whether these aminated metabolites are involved in the reported psychoactive and hallucinogenic effects of botanical sources of these allylbenzenes like nutmeg is not known.
=== Genetics === The amount of body fat a person retains, and the speed with which his or her body converts food into energy are all influenced by genetics. But how much influence genetics has as a whole had been debated. The involvement of the central nervous system in body weight management is supported by recent advances in obesity genetics. This happens through the control of long-term energy use and other systems (such as the food reward mechanism), demonstrating that the cause of obesity cannot be limited only to peripherally mediated pathways. The environment, the five senses, stress, emotions, reward, sleep, eating disorders, and information gaps all have an impact on how we eat. McGill University conducted a study on obesity is genetically intertwined with brain structure and mental performance. Through their research, we believe that there is a link between obesity, the brain, and genetics.
Sources: en.wikipedia.org
The news website Tortoise Media reports that the Conservatives have received a further £5m in donations from Frank Hester that are yet to be declared. 16 March Vaughan Gething is elected to lead Welsh Labour, and will become First Minister of Wales. He will be Wales's first black leader, and the first black person to lead a country in Europe. Sainsbury's apologises to its online customers after a technical error meant that orders could not be fulfilled. 18 March – At Manchester Crown Court, Jacob Graham is sentenced to 13 years in prison together with a further five year extended period on licence for creating a "freedom encyclopaedia" containing details on how to build weapons for the purposes of terrorism. 19 March At Southend Crown Court, 39-year-old Nicholas Hawkes, the first person in England and Wales to be convicted of cyberflashing, is sentenced to 66 weeks in prison. This new offence follows passage of the Online Safety Act, which came into effect on 31 January. HMRC announces that its self-assessment helpline will be closed for six months of the year, with the line scheduled to close from 8 April to 30 September. Customers seeking help during that period will be forced to use an online chatbot. The British Board of Film Classification updates its guidelines, meaning films containing scenes of sex or nudity are more likely to receive a 15 rather than a 12A rating going forward. 20 March Inflation falls from 4% to 3.4%, its lowest rate since September 2021.
The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis provides tensile strength and elasticity to the skin through an extracellular matrix composed of collagen fibrils, microfibrils, and elastic fibers, embedded in hyaluronan and proteoglycans. Skin proteoglycans are varied and have very specific locations. For example, hyaluronan, versican and decorin are present throughout the dermis and epidermis extracellular matrix, whereas biglycan and perlecan are only found in the epidermis. It harbors many mechanoreceptors (nerve endings) that provide the sense of touch and heat through nociceptors and thermoreceptors. It also contains the hair follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels and blood vessels. The blood vessels in the dermis provide nourishment and waste removal from its own cells as well as for the epidermis. Dermis and subcutaneous tissues are thought to contain germinative cells involved in formation of horns, osteoderm, and other extra-skeletal apparatus in mammals. The dermis is tightly connected to the epidermis through a basement membrane and is structurally divided into two areas: a superficial area adjacent to the epidermis, called the papillary region, and a deep thicker area known as the reticular region.
At the turn of the twentieth century the theoretical underpinnings of chemistry were finally understood due to a series of remarkable discoveries that succeeded in probing and discovering the very nature of the internal structure of atoms. In 1897, J.J. Thomson of the University of Cambridge discovered the electron and soon after the French scientist Becquerel as well as the couple Pierre and Marie Curie investigated the phenomenon of radioactivity. In a series of pioneering scattering experiments Ernest Rutherford at the University of Manchester discovered the internal structure of the atom and the existence of the proton, classified and explained the different types of radioactivity and successfully transmuted the first element by bombarding nitrogen with alpha particles. His work on atomic structure was improved on by his students, the Danish physicist Niels Bohr, the Englishman Henry Moseley and the German Otto Hahn, who went on to father the emerging nuclear chemistry and discovered nuclear fission. The electronic theory of chemical bonds and molecular orbitals was developed by the American scientists Linus Pauling and Gilbert N. Lewis. The year 2011 was declared by the United Nations as the International Year of Chemistry. As one of the United Nations' many International Year designations, it was an initiative to broaden outreach and public understanding in chemistry. The year was chosen as the 100th anniversary of Marie Curie's receipt of the Nobel Prize in Chemistry. Several years later, in 2019, the UN declared the International Year of the Periodic Table.
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.