A practical reference on Research chemical: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-25. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
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.
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.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
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.
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.
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.
=== Propagation === Seeds of A. chilensis germinate without cold stratification. In zones with the possibility of frost, it is recommended to sow in spring in a greenhouse. If they have grown enough, by autumn, the new plants can be planted into individual pots. The potted plants should stay in the greenhouse for the first winter. The following year, after the last expected frost in spring, the plants can be planted out into their final positions. In their first winter outdoors, some type of frost protection is required. For further propagation, vegetative propagation is possible: cuttings of wood with a length of 15 to 30 centimetres (5.9 to 11.8 in) can be planted into pots. These cuttings normally root, and can be planted out in the following spring.
Mechanical properties of cellulose in primary plant cell wall are correlated with growth and expansion of plant cells. Live fluorescence microscopy techniques are promising in investigation of the role of cellulose in growing plant cells.
=== Stille–Kelly coupling === Using the seminal publication by Eaborn in 1976, which forms arylstannanes from arylhalides and distannanes, T. Ross Kelly applied this process to the intramolecular coupling of arylhalides. This tandem stannylation/aryl halide coupling was used for the syntheses of a variety of dihydrophenanthrenes. Most of the internal rings formed are limited to 5 or 6 members, however some cases of macrocyclization have been reported. Unlike a normal Stille coupling, chlorine does not work as a halogen, possibly due to its lower reactivity in the halogen sequence (its shorter bond length and stronger bond dissociation energy makes it more difficult to break via oxidative addition). Starting in the middle of the scheme below and going clockwise, the palladium catalyst (1) oxidatively adds to the most reactive C-X bond (13) to form 14, followed by transmetalation with distannane (15) to yield 16 and reductive elimination to yield an arylstannane (18). The regenerated palladium catalyst (1) can oxidative add to the second C-X bond of 18 to form 19, followed by intramolecular transmetalation to yield 20, followed by reductive elimination to yield the coupled product (22).
The following classification system for transmembrane solute transporters has been constructed in the TCDB. Three families of ABC exporters are defined by their evolutionary origins. ABC1 exporters evolved by intragenic triplication of a 2 TMS precursor (TMS = transmembrane segment. A "2 TMS" protein has 2 transmembrane segments) to give 6 TMS proteins. ABC2 exporters evolved by intragenic duplication of a 3 TMS precursor, and ABC3 exporters evolved from a 4 TMS precursor which duplicated either extragenicly to give two 4 TMS proteins, both required for transport function, or intragenicly to give 8 or 10 TMS proteins. The 10 TMS proteins appear to have two extra TMSs between the two 4 TMS repeat units. Most uptake systems (all except 3.A.1.21) are of the ABC2 type, divided into type I and type II by the way they handle nucleotides. A special subfamily of ABC2 importers called ECF use a separate subunit for substrate recognition. ABC1 (InterPro: IPR036640): ABC2 (InterPro: IPR000412 [partial]): ABC3 (InterPro: IPR003838):
NETA metabolizes into ethinylestradiol at a rate of 0.20 to 0.33% across a dose range of 10 to 40 mg. Peak levels of ethinylestradiol with a 10, 20, or 40 mg dose of NETA were 58, 178, and 231 pg/mL, respectively. For comparison, a 30 to 40 μg dose of oral ethinylestradiol typically results in a peak ethinylestradiol level of 100 to 135 pg/mL. As such, in terms of ethinylestradiol exposure, 10 to 20 mg NETA may be equivalent to 20 to 30 μg ethinylestradiol and 40 mg NETA may be similar to 50 μg ethinylestradiol. In another study however, 5 mg NETA produced an equivalent of 28 μg ethinylestradiol (0.7% conversion rate) and 10 mg NETA produced an equivalent of 62 μg ethinylestradiol (1.0% conversion rate). Due to its estrogenic activity via ethinylestradiol, high doses of NETA have been proposed for add-back in the treatment of endometriosis without estrogen supplementation. Generation of ethinylestradiol with high doses of NETA may increase the risk of venous thromboembolism but may also decrease menstrual bleeding relative to progestogen exposure alone.
Sources: en.wikipedia.org
The US Food and Drug Administration has issued warning letters to firms including colloidal silver marketers for selling products with false and misleading claims to prevent, treat, mitigate, diagnose or cure coronavirus disease 2019 (COVID-19). In 2020, televangelist felon Jim Bakker was sued by the Missouri Attorney General (AG) for marketing colloidal silver products and making false claims about their effectiveness against COVID-19. The Attorney General of New York sent a cease and desist order to Bakker and others about peddling the unproven products that were compared to selling "snake oil", and the Food and Drug Administration also warned Bakker about his actions. Controversial web show host, podcaster and conspiracy theorist Alex Jones was also warned by the New York Attorney General's office to stop marketing his colloidal silver infused products (toothpaste, mouthwash, dietary supplements, etc.) because he made unproven claims of its ability to fend off COVID-19.
Seizures are characterized by high levels of synchronized neuronal activity. One important regulator of neuronal activity is the hyperpolarizing A-type current mediated by potassium channel KV4.2. miR-324-5p downregulates KV4.2, exacerbating conditions that lead to seizure onset, and downregulation of miR-324-5p in mouse models of epilepsy is seizure-suppressive. Changes in miRNA expression are seen in epileptogenesis and in other disease pathologies. In epilepsy, miR-324-5p expression has been shown to increase and decrease at different timepoints and loci. Importantly, miR-324-5p has increased association with the RISC complex following seizure in mice, indicating more suppressive activity. Overall, this suggests that miR-324-5p plays a role in epileptogenesis via targeting of potassium channel KV4.2. miR-324-5p contributes to cardiac disease pathophysiology and cardiomyocite death through translational inhibition of Mtfr1, leading to reduced mitochondrial fission, apoptosis, and myocardial infarction.
CAVE systems included multiple flat screen displays, typically at least three walls to surround the human player, and incorporated some type of tracking sensor system to match the images on the walls to what direction the player was looking. Early applications of CAVE system were game-based demonstrations, but the cost remained prohibitive for commercial deployment even through the 2010s. Around this same time in the 1990s, major innovations in real-time 3D graphics had been made across computer, console, and arcade video games, and with further improvements in affordable consumer technologies, arcade games began to decline as they could not compete with these innovations. Arcade game manufacturers instead focused on offering games that could not easily be replicated at home, which included the introduction of VR-based arcade games. For example, the Virtuality Group produced its Virtuality line of arcade games starting in the early 1990s that typically included a VR headset with head-tracking and other features. However, the cost and upkeep of these machines made it difficult to continue support for them. There remained strong interest from academics to explore what VR, along with augmented reality and other mixed reality systems, could bring to video games, through the 2000s, but these games were mostly prepared for research proof-of-concepts to demonstrate the interaction of VR hardware, software, and human motion rather than for commercial release, since hardware costs were still high.
=== Mechanism of action === Dasiglucagon operates through the same mechanism as endogenous glucagon, acting as an agonist at glucagon receptors expressed throughout the body, which are G-coupled receptors. Binding to liver glucagon receptors, dasiglucagon activates Gsα and Gq, resulting in the activation of adenylate cyclase. This, in turn, increases intracellular cyclic AMP levels, stimulating glycogenolysis and gluconeogenesis in the liver. As glucose is primarily released from liver glycogen stores, the presence of glycogen stores in the liver is essential for dasiglucagon to exert its antihypoglycemic effects
Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P, scientitifically known as 4-formyl-5-hydroxy-6-methylpyridin-3-yl)methyl dihydrogen phosphate, the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates.
Sources: en.wikipedia.org
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
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.