The short version of Selank fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-13. Anything still debated is marked as such rather than presented as settled.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
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.
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.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
== Historical timeline == 1895 Wilhelm Conrad Röntgen discovers X-rays ("bremsstrahlung", from German for radiation produced by deceleration) 1896 Antoine Henri Becquerel discovers natural radioactivity; Minck proposes the therapeutic use 1904 Samuel Prescott describes the bactericide effects Massachusetts Institute of Technology (MIT) 1906 Appleby & Banks: UK patent to use radioactive isotopes to irradiate particulate food in a flowing bed 1918 Gillett: U.S. Patent to use X-rays for the preservation of food 1921 Schwartz describes the elimination of Trichinella from food 1930 Wuest: French patent on food irradiation 1943 MIT becomes active in the field of food preservation for the U.S. Army 1951 U.S. Atomic Energy Commission begins to co-ordinate national research activities 1958 World first commercial food irradiation (spices) at Stuttgart, Germany 1963 FDA approves food irradiation. NASA begins irradiating astronaut food items to prevent food borne illness during space missions.
=== Extraterrestrial === Beyond Earth, strong evidence suggests the presence of calcium carbonate on Mars. Signs of calcium carbonate have been detected at more than one location (notably at Gusev and Huygens craters). This provides some evidence for the past presence of liquid water.
Most people with gallstones do not have symptoms. However, when a gallstone temporarily lodges in the cystic duct, they experience biliary colic. Biliary colic is abdominal pain in the right upper quadrant or epigastric region. It is episodic, occurring after eating greasy or fatty foods, and leads to nausea and/or vomiting. People with cholecystitis most commonly have symptoms of biliary colic before developing cholecystitis. The pain becomes severe and constant in cholecystitis. Nausea is common and vomiting occurs in 75% of people with cholecystitis. In addition to abdominal pain, right shoulder pain can be present. On physical examination, an inflamed gallbladder is almost always tender to the touch and palpable (~25-50% of cases) in the midclavicular right lower rib margin. Additionally, a fever is common. Murphy's sign, pain when exhaling while pressing on the right upper abdomen, can also indicate cholecystitis. Yellowing of the skin (jaundice) may occur but is often mild. Severe jaundice suggests another cause of symptoms such as choledocholithiasis. People who are old, have diabetes, chronic illness, or who are immunocompromised may have vague symptoms that may not include fever or localized tenderness.
Polymerase chain reaction (PCR) is the primary gene amplification technique that has revolutionized modern biochemistry. Polymerase chain reaction was developed by Kary Mullis in 1983. There are four steps to a proper polymerase chain reaction: 1) denaturation 2) extension 3) insertion (of gene to be expressed) and finally 4) amplification of the inserted gene. These steps with simple illustrative examples of this process can be seen in the image below and to the right of this section. This technique allows for the copy of a single gene to be amplified into hundreds or even millions of copies and has become a cornerstone in the protocol for any biochemist that wishes to work with bacteria and gene expression. PCR is not only used for gene expression research but is also capable of aiding laboratories in diagnosing certain diseases such a lymphomas, some types of leukemia, and other malignant diseases that can sometimes puzzle doctors. Without polymerase chain reaction development, there are many advancements in the field of bacterial study and protein expression study that would not have come to fruition. The development of the theory and process of polymerase chain reaction is essential but the invention of the thermal cycler is equally as important because the process would not be possible without this instrument. This is yet another testament to the fact that the advancement of technology is just as crucial to sciences such as biochemistry as is the painstaking research that leads to the development of theoretical concepts.
Sources: en.wikipedia.org
=== Neurotoxicity === Laboratory studies in rats indicate that ibogaine at high doses may cause degeneration of Purkinje cells in the cerebellum. This also occurred with the related drug harmaline. However, subsequent research found no evidence of this neurotoxicity with ibogaine in a primate. In limited human research, neuropathological examination revealed no evidence of neuronal degenerative changes in an adult female patient who had received four separate doses of ibogaine ranging between 10 and 30 mg/kg over a 15-month interval. A published series of fatalities associated with ibogaine ingestion also found no evidence for consistent neurotoxicity.
According to the White House's website, whitehouse.gov, more than 200 organizations have stated their support for the OBBBA, including AT&T, Comcast, American Airlines, Delta Air Lines, the National Retail Federation, and the National Taxpayers Union. Trump has claimed that the bill is the "single most popular bill ever signed", a claim that CNN disputed, saying "That is an up-is-down reversal of reality. ... While polls can be off, this bill wouldn't be popular – let alone the most popular US bill ever signed – even with a massive and widespread polling error."
==== Texas ==== In February 2022, Texas Attorney General Ken Paxton initiated an investigation into TikTok for alleged violations of children's privacy and facilitation of human trafficking. Paxton claimed that the Texas Department of Public Safety gathered several pieces of content showing the attempted recruitment of teenagers to smuggle people or goods across the Mexico–United States border. He claimed the evidence may prove the company's involvement in "human smuggling, sex trafficking and drug trafficking". The company claimed that no illegal activity of any kind is supported on the platform.
Sources: en.wikipedia.org
The molecular analysis of the octopods shows that the suborder Cirrina (Cirromorphida) and the superfamily Argonautoidea are paraphyletic and are broken up; these names are shown in quotation marks and italics on the cladogram.
==== Actions ==== RO5073012 has high affinity for the mouse, rat, cynomolgus monkey, and human TAAR1 (Ki = 0.5–6 nM), is highly potent and selective as an agonist of the TAAR1 of these species (EC50Tooltip half-maximal effective concentration = 8.8–25 nM), and has relatively low intrinsic activity at the TAAR1 of these species (EmaxTooltip maximal efficacy = 24–43% relative to β-phenethylamine).
== Definition == Due to inconsistent definitions in the literature, Osborne's ligament can be classified as the fibrous band bridging the two heads of the FCU as originally described by Osborne or the ligamentous tissue connecting the olecranon and the medial epicondyle. Different terminologies have also been used to describe the tissues, including ligamentum epitrochleo-anconeum and epitrochleo-olecranal ligament, further contributing to the problem of clarifying the definitions.
=== Linear traps and TOF === A TOF mass spectrometer can also have a low-duty cycle when coupled with a continuous ion source. Combining an ion trap with a TOF mass analyzer can improve the duty cycle. Both 3D and linear traps have been combined with TOF mass analyzers. A trap can also add MSn capabilities to the system.
Sources: en.wikipedia.org
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.