The short version of anxiolytic fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-30 and is reviewed periodically as new material appears.
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 was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
| 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 |
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.
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 studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
==== MeSH E05.478.550 – immunization ==== MeSH E05.478.550.520 – immunization, passive MeSH E05.478.550.520.050 – adoptive transfer MeSH E05.478.550.520.050.400 – immunotherapy, adoptive MeSH E05.478.550.545 – immunization schedule MeSH E05.478.550.550 – immunization, secondary MeSH E05.478.550.600 – immunotherapy, active MeSH E05.478.550.600.890 – vaccination MeSH E05.478.550.650 – mass immunization
Electron-capture dissociation (ECD) is a method of fragmenting gas-phase ions for structure elucidation of peptides and proteins in tandem mass spectrometry. It is one of the most widely used techniques for activation and dissociation of mass selected precursor ion in MS/MS. It involves the direct introduction of low-energy electrons to trapped gas-phase ions.
== Overdose == Excessive doses of metoprolol can cause bradycardia, hypotension, metabolic acidosis, seizures, and cardiorespiratory arrest. Blood or plasma concentrations may be measured to confirm a diagnosis of overdose or poisoning in hospitalized patients or to assist in a medicolegal death investigation. Plasma levels are usually less than 200 μg/L during therapeutic administration, but can range from 1–20 mg/L in overdose victims.
Sources: en.wikipedia.org
== Early life and education == David Andrew Jerome Samberg was born in Berkeley, California, on August 18, 1978. His mother, Marjorie "Margi" (née Marrow), is a retired teacher, who taught at John Muir Elementary School, and his father, Joe Samberg, is a photographer. He has two older sisters, Johanna and Darrow. His family is Jewish, and Samberg described his upbringing as "I wouldn't say we're super-religious, but we're very much in touch with the cultural aspect of it." Samberg never had a bar mitzvah. He attended Chabot Elementary School with his future Brooklyn Nine-Nine co-star Chelsea Peretti. At age 5, he told his parents that he wanted to change his name to Andy. In a 2019 episode of Finding Your Roots, hosted by Henry Louis Gates Jr., Samberg discovered that his mother Marjorie, who was adopted by Jewish parents, is the biological daughter of a Sicilian Catholic father named Salvatore Maida, who immigrated in 1925, and a German Jewish refugee mother named Ellen Philipsborn, who had come to the U.S. in 1938; they met in San Francisco. Samberg's adoptive maternal grandfather was industrial psychologist and philanthropist Alfred J. Marrow; through him, he is a third cousin of U.S. senator Tammy Baldwin (D-WI). Samberg graduated from Berkeley High School in 1996, where he became interested in creative writing and has stated that writing classes "were the ones that I put all my effort into... that's what I cared about and that's what I ended up doing".
He added that Afghanistan had taken serious measures to ensure its territory was not used against Pakistan and said its military actions were defensive. Pakistan's Defence Minister, Khawaja Asif, implicitly confirmed that indirect talks with the Afghan Taliban were taking place through third-party mediators, although he described the process as unstructured and informal. He added that if the efforts failed to secure peace, Pakistan could return to its previous approach and escalate military operations in parts of Afghanistan. Pakistani military claimed to have killed 10 TTP militants in an operation in Khyber District and three more in Bannu. On 31 March, Taliban and Pakistani forces clashed in Dangam District of Kunar Province. On 1 April, 4 police personnel and 5 civilians were injured in an improvised explosive device (IED) blast carried out by Pakistani Taliban in Pakistan's Lakki Marwat district. On 2 April, Pakistani officials said that they foiled an infiltration attempt along the Afghanistan–Pakistan border, killing eight militants and seizing a large quantity of weapons and ammunition. That same day, Taliban and Pakistani officials confirmed that they were holding preliminary talks mediated by China in Ürümqi. Pakistani officials described the talks as working-level and said that they had sent their mid-level delegation to take part in the talks.
=== Andy Harris === Andy Harris is Jackie and Fred's son, born in 1994 on the episode "Labor Day". Jackie breastfeeds Andy at the altar while marrying Fred ("Altar Egos"). Andy was the ringbearer at Darlene and David's wedding ("The Wedding"). Jackie occasionally dressed him in outfits Fred deemed to be feminine. D.J. made it a point to spend time with Andy because they were the only younger males in the family until Jerry's birth. Cousins Andy and Jerry took naps together in the same crib when they were babies. Andy has been retconned out of existence in The Conners, with producer Bruce Helford explaining that the new show's producers have chosen to deliberately ignore certain developments of later seasons of Roseanne—including Andy's birth.
=== Clipse Week with Genius === Clipse collaborated with lyrics website and media company Genius for a series named Clipse Week. It began with a Genius Verified video for "Chains & Whips" on July 11, 2025. Verified is a series in which artists explain their songs' lyrical meaning and inspiration. Malice spoke about his faith, his time away from Clipse, and what made him return; he also commented on the perception that Pusha T is too outspoken about industry peers, arguing that his brother's statements are actually mild: "I truly admire his restraint. People think he goes over the top and just with me knowing where all the bodies are buried, I admire his restraint." Pusha T revealed that the chorus was started by Williams when the duo was stuck during the writing process. On the same day, Malice wrote official annotations for each track on Let God Sort Em Out through his verified Genius account. A Genius Verified video for "Ace Trumpets" was released on July 14.
Sources: en.wikipedia.org
== Interpretation == One study reviewed the relative diagnostic value of enzyme and bicarbonate concentrations compared with enzyme output in 363 secretin-CCK tests. The investigators also evaluated the requirement for perfusion markers to accurately quantify volume, and the validity of a shortened sampling time (first 20 minutes). Only 60 percent of volume was recovered with the duodenal aspiration tube, suggesting that marker perfusion to correct for distal loss of secretion is important to accurately quantify volume. Using a trypsin output <50 U/kg/h as the reference standard, measurement of enzyme concentration alone misclassified approximately 10 percent of patients. Use of a shortened collection time misclassified approximately 4 percent of patients. The authors concluded that this was an unacceptably high rate of misclassification and that the standard prolonged collection of fluid using a perfusion marker must be performed to accurately measure exocrine function.
== Origins == Ubayd Allah was the son of Ziyad ibn Abihi whose tribal origins were obscure; while his mother was a Persian concubine named Murjanah. Ziyad served as the Umayyad governor of Iraq and the lands east of that province, collectively known as Khurasan, during the reign of Caliph Mu'awiya I (r. 661–680).
Tears (tear film) are a transparent fluid secreted primarily by the lacrimal glands (tear gland) found in the eyes of all land mammals. According to the mode of production, tears are classified into four types: basal, closed eye, emotional, and reflex. The basal rate of tear secretion is ~0.5–2.2 μL/min, and irritation can increase secretion by up to ~100-fold, reaching ~300 μL/min. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The four types of tears differ significantly in their composition.
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 heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.