Everything below concerns GABA-A receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-10-30. Numbers and descriptions here follow the published literature rather than marketing material.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Reversed-phase HPLC retention time versus reference standard | Retention depends on column, gradient, and ion-pairing agent |
| Mass confirmation | Electrospray or MALDI mass spectrometry | Doubly protonated ion near m/z 377 is consistent with about 752 Da |
| Typical purity specification | 95 percent or higher by chromatographic peak area | Lower values suggest truncated or modified peptide species |
| Storage of lyophilized powder | -20 °C, desiccated, protected from light | Powder tolerates long storage better than solution |
| Storage of solution | 2-8 °C for short periods | Freeze-thaw cycling promotes aggregation and surface adsorption |
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.
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.
==== Adverse effects on public health ==== Public health and policy researchers at Yale University and the University of Pennsylvania sent a letter to Senate leaders warning that cuts to health programs in the bill would lead to over 51,000 preventable deaths annually.
Proposed mitigation strategies include factoring potential environmental costs prior to model development or data collection, increasing efficiency of data centers to reduce electricity/energy usage, building more efficient machine learning models, minimizing the number of times that models need to be retrained, developing a government-directed framework for auditing the environmental impact of these models, regulating for transparency of these models, regulating their energy and water usage, encouraging researchers to publish data on their models' carbon footprint, and increasing the number of subject matter experts who understand both machine learning and climate science.
=== Obstetric use === Methylergometrine is a smooth muscle constrictor that mostly acts on the uterus. It is most commonly used to prevent or control excessive bleeding following childbirth and spontaneous or elective abortion, and also to aid in expulsion of retained products of conception after a missed abortion (miscarriage in which all or part of the fetus remains in the uterus) and to help deliver the placenta after childbirth. It is available as tablets or injection (IM or IV) or in liquid form to be taken orally.
Sources: en.wikipedia.org
Profilin allergy is significantly associated with respiratory allergy to grass pollen ( hay fever). After a person first becomes allergic to profilin through inhalation of grass or tree pollen, allergy to profilin-containing food and development of pollen-food syndrome occurs How often pollen-allergic people across Europe become profilin allergic varies widely; As of 1997, from about 5% of Swedish birch pollen–allergic people to 51% in Spanish people allergic to Mercurialis annua were profilin allergic. Profilin is the major allergen of certain food plants, for example, melon, orange, and soybean and thus allergy to melon, citrus fruits, tomato, and banana is a clinical marker of profilin hypersensitivity. As of 2018 there was no "solid therapeutic approach" to treat profilin allergy. As of 2018, the list of members of the profilin family identified as allergens contained:
== Active Ingredients: Weight Loss Efficacy & Potential Side Effects Caffeine === The caffeine content in the daily recommended dose of Dexatrim products ranges from 50–400 mg per day. There are a number of studies showing that caffeine has a short-term stimulatory effect on basal metabolic rate. However, in 1992, in a double-blind placebo controlled study, caffeine (at a dose of 200 mg daily) was found to be no more effective in promoting weight loss than a placebo. Potential side effects of caffeine may include insomnia, anxiety, gastrointestinal discomfort, diarrhea, headaches and abnormal heart beat. Green tea extract is currently used for a variety of conditions including improving mental alertness and aiding in weight loss. There is currently insufficient data to determine the efficacy of green tea extract in aiding weight loss. In addition to the potential side effects from the caffeine content in green tea extract, there is some risk of liver problems associated with green tea extract consumption. Liver problems have not been observed with the use of green tea in beverages.
=== Unstable isotopes === The suitable half-life and decay mode made lutetium-176 used as a pure beta emitter, using lutetium which has been exposed to neutron activation, and in lutetium–hafnium dating to date meteorites. The isotope 177Lu emits low-energy beta particles and gamma rays and has a half-life around 7 days, positive characteristics for commercial applications, especially in therapeutic nuclear medicine. The synthetic isotope lutetium-177 bound to octreotate (a somatostatin analogue), is used experimentally in targeted radionuclide therapy for neuroendocrine tumors. Lutetium-177 is used as a radionuclide in neuroendocrine tumor therapy and bone pain palliation. Lutetium (177Lu) vipivotide tetraxetan is a therapy for prostate cancer, FDA approved in 2022.
Sources: en.wikipedia.org
=== Medicinal === Like G. lucidum, G. tsugae is purported to have medicinal properties including use for dressing a skin wound. Though phylogenetic analysis has begun to better differentiate between many closely related species of Ganoderma; there is still disagreement as to which have the most medicinal properties. Natural and artificial variations (e.g. growing conditions and preparation) may also affect any medicinal value. Studies in mice have shown that G. tsugae shows several potential medicinal benefits including anti-tumor activity through some of the active polysaccharides found in G. tsugae. G. tsugae has also been shown to significantly promote wound healing in mice as well as markedly increase the proliferation and migration of fibroblast cells in culture.
== Drinking water hazards == Untreated water may contain potentially pathogenic agents, including protozoa, bacteria, viruses, and some larvae of higher-order parasites such as liver flukes and roundworms. Chemical pollutants such as pesticides, heavy metals and synthetic organics may be present. Other components may affect taste, odour and general aesthetic qualities, including turbidity from soil or clay, colour from humic acid or microscopic algae, odours from certain type of bacteria, particularly Actinomycetes which produce geosmin, and saltiness from brackish or sea water. Common metallic contaminants such as copper and lead can be treated by increasing the pH using soda ash or lime, which precipitates such metals. Careful decanting of the clear water after settlement or the use of filtration provides acceptably low levels of metals. Water contaminated by aluminium or zinc cannot be treated in this way using a strong alkali as higher pHs re-dissolve the metal salts. Salt is difficult to remove except by reverse osmosis or distillation. Most portable treatment processes focus on mitigating human pathogens for safety and removing particulates matter, tastes and odours. Significant pathogens commonly present in the developed world include Giardia, Cryptosporidium, Shigella, hepatitis A virus, Escherichia coli, and enterovirus. In less developed countries there may be risks from cholera and dysentery organisms and a range of tropical enteroparasites.
Rearing a relatively small number of grazing animals can be beneficial, as the Food Climate Research Network at Surrey University reports: "A little bit of livestock production is probably a good thing for the environment". In May 2009, Ghent, Belgium, was reported to be "the first [city] in the world to go vegetarian at least once a week" for environmental reasons, when local authorities decided to implement a "weekly meatless day". Civil servants would eat vegetarian meals one day per week, in recognition of the United Nations' report. Posters were put up by local authorities to encourage the population to take part on vegetarian days, and "veggie street maps" were printed to highlight vegetarian restaurants. In September 2009, schools in Ghent are due to have a weekly veggiedag ("vegetarian day") too. Public opinion and acceptance of meat-free food is expected to be more successful if its descriptive words focus less on the health aspects and more on the flavor.
=== Function === Nelson DL; Cox MM (2004). Lehninger Principles of Biochemistry (4th ed.). W. H. Freeman. ISBN 978-0-7167-4339-2. Bugg T (2004). Introduction to Enzyme and Coenzyme Chemistry (2nd ed.). Blackwell Publishing Limited. ISBN 978-1-4051-1452-3. Lee HC (2002). Cyclic ADP-Ribose and NAADP: Structure, Metabolism and Functions. Kluwer Academic Publishers. ISBN 978-1-4020-7281-9. Levine OS, Schuchat A, Schwartz B, Wenger JD, Elliott J (1997). "Generic protocol for population-based surveillance of Haemophilus influenzae type B" (PDF). World Health Organization. Centers for Disease Control. p. 13. WHO/VRD/GEN/95.05. Archived from the original (PDF) on 1 July 2004. Kim, Jinhyun; Lee, Sahng Ha; Tieves, Florian; Paul, Caroline E.; Hollmann, Frank; Park, Chan Beum (5 July 2019). "Nicotinamide adenine dinucleotide as a photocatalyst". Science Advances. 5 (7) eaax0501. Bibcode:2019SciA....5..501K. doi:10.1126/sciadv.aax0501. PMC 6641943. PMID 31334353.
Sources: en.wikipedia.org
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.
Lyophilized powder is normally stored desiccated at -20 °C, protected from light and moisture. Powder kept under these conditions is generally stable for long periods. Solutions are less stable and are usually prepared immediately before use.
A purity value from one chromatographic method does not capture every possible impurity. Related peptides with similar retention behavior, counterions, and residual solvents may not appear in the same analysis. Independent testing with an orthogonal method provides stronger assurance of identity and content.
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.