Everything below concerns intranasal delivery. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-28. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
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.
=== Trials for cardiovascular health === In March 2024, the US Food and Drug Administration expanded the indication for semaglutide (brand name Wegovy) to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and who are either obese or overweight. This was based on a placebo-controlled randomized double-blind trial, which was sponsored by Novo Nordisk, on the efficacy and safety of semaglutide for this indication. 17,604 participant were randomly assigned to receive either semaglutide (Wegovy) or placebo. Participants in both groups also received standard-of-care medical treatment (e.g., management of blood pressure and cholesterol) and healthy lifestyle counseling (including diet and physical activity). The trial reported cumulative occurrence of major adverse cardiovascular events, a primary end-point event of the trial, for 569 of the 8803 patients in the semaglutide group, which were 6.5% of the participants, and for 701 of the 8801 patients in the placebo group, which were 8% of the participants, showing relative 18.8% less major adverse cardiovascular events, such as death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke, occurring for participants who had received semaglutide in the trial relative to those who had received placebo over the course of around 48 months, or 34.2±13.7 months, which was the mean (±SD) total duration of the participants in either group's exposure to the placebo or semaglutide during the trial.
==== Basis for different types of T-cell help ==== How these different methods operate, the forms of antigen expressed, and the different profiles of T-cell help is not understood. It was thought that the relatively large amounts of DNA used in IM injection were responsible for the induction of TH1 responses. However, evidence shows no dose-related differences in TH type. The type of T-cell help raised is determined by the differentiated state of antigen presenting cells. Dendritic cells can differentiate to secrete IL-12 (which supports TH1 cell development) or IL-4 (which supports TH2 responses). pDNA injected by needle is endocytosed into the dendritic cell, which is then stimulated to differentiate for TH1 cytokine (IL-12) production, while the gene gun bombards the DNA directly into the cell, thus bypassing TH1 stimulation.
The risk of experiencing severe withdrawal symptoms is high if a patient has become physically or mentally dependent and discontinues tapentadol abruptly. These symptoms can range from mild discomfort to more serious health issues, making abrupt cessation dangerous. When a person has been using tapentadol regularly for an extended period of time, tapering off the drug gradually is generally recommended. This approach allows the body to adjust to lower doses over time, minimizing the risk of withdrawal symptoms and ensuring a safer transition away from tapentadol. Gradual withdrawal helps to avoid the shock to the system that comes with abrupt discontinuation, ultimately making the process more manageable for a person who has developed a dependence. The symptoms of tapentadol withdrawal are typical of other opioids and can include anxiety, restlessness, fever or chills, joint pain, nausea or vomiting, loss of appetite, runny nose, stomach cramps, sweating, tremor, or insomnia. However, tapentadol withdrawal symptoms may be more intense and prolonged when compared with more typical opioids such as codeine or oxycodone, in some respects, due to the fact that tapentadol acts also as norepinephrine reuptake inhibitor (NRI). People withdrawing from a tapentadol dependency may experience both typical opioid withdrawal symptoms, such as fever or nausea, along with symptoms associated more commonly with the discontinuation of drugs which block the reuptake of norepinephrine.
In the United States, pembrolizumab is indicated for the treatment of melanoma, non-small-cell lung cancer, malignant pleural mesothelioma, head and neck squamous-cell cancer, classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, urothelial cancer, microsatellite instability-high or mismatch repair deficient cancer, microsatellite instability-high or mismatch repair deficient colorectal cancer, gastric cancer, esophageal cancer, cervical cancer, hepatocellular carcinoma, biliary tract cancer, Merkel-cell carcinoma, renal cell carcinoma, endometrial carcinoma, tumor mutational burden-high cancer, cutaneous squamous cell carcinoma, and triple-negative breast cancer. As of 2019, pembrolizumab is used via intravenous infusion to treat inoperable or metastatic melanoma, metastatic non-small cell lung cancer (NSCLC) in certain situations, as a first-line treatment for metastatic bladder cancer in people who cannot receive cisplatin-based chemotherapy and have high levels of PD-L1, as a second-line treatment for head and neck squamous cell carcinoma (HNSCC), after platinum-based chemotherapy, for the treatment of people with refractory classic Hodgkin lymphoma, and recurrent locally advanced or metastatic esophageal squamous cell carcinoma.
Sources: en.wikipedia.org
The brown recluse (Loxosceles reclusa, Sicariidae, formerly placed in a family "Loxoscelidae") is a recluse spider with necrotic venom. Similar to those of other recluse spiders, their bites sometimes require medical attention. The brown recluse is one of two spiders in North America with dangerous venom, the other being the black widow. Brown recluse spiders are usually between 6 and 20 millimetres (0.24 and 0.79 in), but may grow larger. While typically light to medium brown, they range in color from whitish to dark brown or blackish gray. The cephalothorax and abdomen are not necessarily the same color. These spiders usually have markings on the dorsal side of their cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler, or violin spider.
(phosphatase 2A protein)-leucine-carboxy methyltransferase (EC 2.1.1.233) is an enzyme with systematic name S-adenosyl-L-methionine:(phosphatase 2A protein)-leucine O-methyltransferase. This enzyme catalyses the following chemical reaction
== Clinical Research and Clinical Trials == Clinical research at the Barshop Institute is dedicated to translating discoveries in the biology of aging into interventions that improve healthspan, preserve functional independence, and prevent or delay the onset of chronic age-related diseases. The Institute maintains a robust clinical research infrastructure that supports Phase I–IV clinical trials, investigator-initiated studies, and multicenter collaborations spanning basic translational research through large-scale clinical investigations. Investigators conduct studies involving older adults across a broad spectrum of aging-related conditions, including frailty, sarcopenia, metabolic dysfunction, obesity, type 2 diabetes, cardiovascular disease, Alzheimer's disease and related dementias, mobility impairment, osteoporosis, and other chronic conditions that disproportionately affect aging populations. Clinical trials evaluate novel therapeutics, lifestyle interventions, nutritional strategies, exercise programs, and repurposed medications designed to improve physical function, cognitive health, metabolic resilience, and overall quality of life. The Institute's clinical research enterprise is strengthened through close collaboration among physician-scientists, basic scientists, biostatisticians, epidemiologists, rehabilitation specialists, nutrition experts, and clinical research professionals.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
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.