A practical reference on anxiolytic: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-16 and is reviewed periodically as new material appears.
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.
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.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
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.
| 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 |
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
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.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
For the elimination of hazardous chemicals from the water, many treatment procedures have been applied. The processes involved in removing the contaminants include physical processes such as settling and filtration, chemical processes such as disinfection and coagulation, and biological processes such as slow sand filtration. A combination selected from the following processes (depending on the season and contaminants and chemicals present in the raw water) is used for municipal drinking water treatment worldwide.
A variety of other skeletal features are shared by dinosaurs. However, because they either are common to other groups of archosaurs or were not present in all early dinosaurs, these features are not synapomorphies. For example, as diapsids, dinosaurs ancestrally had two pairs of Infratemporal fenestrae (openings in the skull behind the eyes), and as members of the diapsid group Archosauria, had additional openings in the snout and lower jaw. Additionally, several characteristics once thought to be synapomorphies are now known to have appeared before dinosaurs, or were absent in the earliest dinosaurs and independently evolved by different dinosaur groups. These include an elongated scapula, or shoulder blade; a sacrum composed of three or more fused vertebrae (three are found in some other archosaurs, but only two are found in Herrerasaurus); and a perforate acetabulum, or hip socket, with a hole at the center of its inside surface (closed in Saturnalia tupiniquim, for example). Another difficulty of determining distinctly dinosaurian features is that early dinosaurs and other archosaurs from the Late Triassic epoch are often poorly known and were similar in many ways; these animals have sometimes been misidentified in the literature. Dinosaurs stand with their hind limbs erect in a manner similar to most modern mammals, but distinct from most other reptiles, whose limbs sprawl out to either side. This posture is due to the development of a laterally facing recess in the pelvis (usually an open socket) and a corresponding inwardly facing distinct head on the femur.
=== 1.2 === DisplayPort version 1.2 was introduced on 7 January 2010. The most significant improvement of this version is the doubling of the data rate to 17.28 Gbit/s in High Bit Rate 2 (HBR2) mode, which allows increased resolutions, higher refresh rates, and greater color depth, such as 3840 × 2160 at 60 Hz 10 bpc RGB. Other improvements include multiple independent video streams (daisy-chain connection with multiple monitors) called Multi-Stream Transport (MST), facilities for stereoscopic 3D, increased AUX channel bandwidth (from 1 Mbit/s to 720 Mbit/s), more color spaces including xvYCC, scRGB, and Adobe RGB 1998, and Global Time Code (GTC) for sub 1 μs audio/video synchronisation. Also Apple Inc.'s Mini DisplayPort connector, which is much smaller and designed for laptop computers and other small devices, is compatible with the new standard.
=== Names === Methenamine is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, and USPTooltip United States Pharmacopeia, while hexamine is its BANTooltip British Approved Name and JANTooltip Japanese Accepted Name. Brand names of methenamine include Aminoform, Antihydral, Dehydral, Formamine, Formin, Hexamine, Hiprex, Hyophen, Mandelamine, Metenamine, Phosphasal, Urelle, Urex, Uribel, Urimar, Urin DS, Urogesic Blue, Urotropin, and Ustell, among numerous others.
The protective effect of breastfeeding against obesity is consistent, though small, across many studies. A 2013 longitudinal study reported less obesity at ages two and four years among infants who were breastfed for at least four months.
Sources: en.wikipedia.org
GABAB receptor ligands. Agonists: baclofen, propofol, GHB, phenibut. Antagonists: phaclofen, saclofen. GABA reuptake inhibitors: deramciclane, hyperforin, tiagabine. GABA transaminase inhibitors: gabaculine, phenelzine, valproate, vigabatrin, lemon balm (Melissa officinalis). GABA analogues: pregabalin, gabapentin, picamilon, progabide 4-Amino-1-butanol is a biochemical precursor of GABA and can be converted into GABA by the actions of aldehyde reductase (ALR) and aldehyde dehydrogenase (ALDH) with γ-aminobutyraldehyde (GABAL) as a metabolic intermediate.
=== Humanitarian concerns === Critics have raised humanitarian concerns about the impact of U.S. sanctions on civilian populations. Daniel T. Griswold, writing from a conservative Christian perspective, argues that sanctions limit a sanctioned country's people from exercising political liberties and market freedom. In 1997, the American Association for World Health stated the US embargo against Cuba contributed to malnutrition, poor water access, and lack of access to medicine and other medical supplies. The impact of sanctions on mortality has been the subject of several studies. Economist Helen Yaffe estimates U.S. sanctions on Venezuela caused the deaths of 100,000 people between 2014 and 2020 due to difficulty importing medicine and health care equipment. A study by Mark Weisbrot and Jeffrey Sachs estimated sanctions contributed to approximately 40,000 excess deaths in Venezuela between 2017 and 2018, though critics argued the impact of sanctions could not be adequately separated from pre-existing negative trends. Comprehensive sanctions on Iraq by the United Nations Security Council during the 1990s were linked to widespread malnutrition, shortages of medicine, and deterioration of water and electricity infrastructure. A 1999 UNICEF study estimated between 400,000 and 500,000 excess deaths among children under 5 since 1991; however, surveys conducted after 2003 found no evidence of a large sustained rise in under-5 mortality beginning in 1991.
Administratively headquartered in 29 floors of the U.S. Steel Tower in Pittsburgh's Central Business District, UPMC operates as a complete and integrated health provider system that, although legally separate from the University of Pittsburgh, identifies it as a supported organization in its articles of incorporation and remains closely affiliated with the university and its Schools of the Health Sciences including via the existence of mutual board memberships and subsidization of the university's academic programs. Under a collaborative and coordinated decision-making model, UPMC oversees all clinical activity, including a consolidated physicians' practice plan consisting of university faculty, while the University of Pittsburgh remains the guardian of all academic priorities, particularly faculty-based research. UPMC's 24-member Board of Directors equally splits representation between three groups: the University of Pittsburgh, the community at-large, and individuals historically involved in the governance of its system's hospitals. UPMC is composed of three major operating components: Provider Services, Insurance Services, and International and Commercial Services. The latter two divisions include the for-profit health insurance company (UPMC Health Plan) and a for-profit International and Commercial Services Division that seeks to bring health care, management, and technologies to market throughout the world. UPMC is the largest employer in the state of Pennsylvania.
==== Elsewhere ==== Phenazepam was classified as a narcotic in Finland in July 2014. Phenazepam is considered a narcotic in Norway, as per a March 23, 2010 Health Department addition to the Regular Narcotic List. In Russia, phenazepam is a controlled substance since March 22, 2021. In Estonia, phenazepam is a Schedule IV substance under the Narcotic Drugs and Psychotropic Substances Act. Schedule IV is the lowest classification of psychoactive substances in Estonia. It includes prescribable drugs, including other benzodiazepines.
Sources: en.wikipedia.org
Darren Keith McGuire, MD, MHSc is an American cardiologist and clinical trialist specializing in cardiovascular disease prevention and cardiometabolic medicine, particularly the relationship between diabetes and heart disease. He is a Distinguished Teaching Professor of Internal Medicine in the Division of Cardiology at the University of Texas Southwestern Medical Center. He also serves as lead physician of the Parkland Health cardiology clinics and holds the Jere H. Mitchell Distinguished Chair in Cardiovascular Science.
=== Viscosity === If the evolent has high viscosity, it would produce a high backpressure. Consequently, low-viscosity evolents are preferred. IPA is strongly eluting, but also very viscuous, which results in high backpressures. ACN and MeOH are less viscous than IPA, although a mixture of 50:50 percent of MeOH:water is also very viscous. In general, as the ratio of organic solvent:water increases from 0:1 to 1:0, the viscosity increases, then decreases again. In general, backpressure increased when the flow rate is increased, the mobile phase temperature is lowered, or the stationary phase particle size is increased.
Release of a C-terminal basic amino acid (lysine or arginine), preferentially lysine. This is a zinc-activated enzyme found in plasma. It inactivates proteins such as bradykinin and anaphylatoxins in the blood in order to prevent toxic buildup.
=== Electron ionization === By far the most common and perhaps standard form of ionization is electron ionization (EI). The molecules enter into the MS (the source is a quadrupole or the ion trap itself in an ion trap MS) where they are bombarded with free electrons emitted from a filament, not unlike the filament one would find in a standard light bulb. The electrons bombard the molecules, causing the molecule to fragment in a characteristic and reproducible way. This "hard ionization" technique results in the creation of more fragments of low mass-to-charge ratio (m/z) and few, if any, molecules approaching the molecular mass unit. Hard ionization is considered by mass spectrometrists as the employ of molecular electron bombardment, whereas "soft ionization" is charge by molecular collision with an introduced gas. The molecular fragmentation pattern is dependent upon the electron energy applied to the system, typically 70 eV (electronvolts). The use of 70 eV facilitates comparison of generated spectra with library spectra using manufacturer-supplied software or software developed by the National Institute of Standards (NIST-USA). Spectral library searches employ matching algorithms such as Probability Based Matching and dot-product matching that are used with methods of analysis written by many method standardization agencies. Sources of libraries include NIST, Wiley, the AAFS, and instrument manufacturers.
== Overdose == There has been no clinical experience with overdose of EMP. Overdose of EMP may result in pronounced manifestations of the known adverse effects of the medication. There is no specific antidote for overdose of EMP. In the event of overdose, gastric lavage should be used to evacuate gastric contents as necessary and treatment should be symptom-based and supportive. In the case of dangerously low counts of red blood cells, white blood cells, or platelets, whole blood may be given as needed. Liver function should be monitored with EMP overdose. After an overdose of EMP, hematological and hepatic parameters should continue to be monitored for at least 6 weeks. EMP has been used at high doses of as much as 1,260 mg/day by the oral route and 240 to 450 mg/day by intravenous injection.
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.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.