The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-11 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Freely soluble in water | Also in aqueous buffers |
| Typical purity (HPLC) | 95 percent or higher | Lot-dependent |
| Dry powder storage | Minus 20 degrees Celsius | Sealed, dry, protected from light |
| Solution storage | 2 to 8 degrees Celsius | Short-term use |
| Identity confirmation | Mass spectrometry | ESI or MALDI-TOF |
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.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
=== Pharmacokinetics === Escitalopram is a substrate of P-glycoprotein and hence P-glycoprotein inhibitors such as verapamil and quinidine may improve its blood-brain barrier penetrability. In a preclinical study in rats combining escitalopram with a P-glycoprotein inhibitor, its antidepressant-like effects were enhanced.
Zanidatamab, sold under the brand name Ziihera, is a humanized monoclonal antibody used for the treatment of HER2-positive biliary tract cancer and gastroesophageal adenocarcinoma. It is an IgG-like bispecific HER2-directed antibody directed against two non-overlapping domains of HER2. Zanidatamab is produced in Chinese hamster ovary cells. The most common adverse reactions include diarrhea, infusion-related reaction, abdominal pain, and fatigue. Zanidatamab was first granted accelerated approval for medical use in the United States on November 21, 2024, and gained full approval for gastroesophageal cancer on August 25, 2026. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Although, the 2 newspapers had links with the elites of their countries, and shared the commitment to vindicate the prevailing ideologies in the Criollo oligarchies (economic and political liberalism) in tune with the modernizing trends of the time. They also differed in their points of view to conceive of Americanism, being clearly distant in their approaches. While El Mercurio was totally convinced in promoting the cause of American solidarity, without making distinctions between brother and equal countries, La Nación, for its part, expressed contempt for these excessively fraternal tendencies, invoking the dichotomy between civilization and barbarism as a criterion to privilege before defining the American cause (presenting himself to the civilized Argentine and Uruguayan society as opposed to Paraguayan and Peruvian barbarism), to justify his actions in the war against Paraguay, as well as the repression of the liberal Buenos Aires government to the conservative uprisings through the interior of the country; They also wanted to legitimize the Eurocentric tendencies present in the Argentine elite and their unreserved acceptance of the prevailing social Darwinism, where Peruvian society (and the mestizo heritage in Latin America in general) was frowned upon for not being majority white societies, generating contempt. Also, during the 1978 FIFA World Cup, it was reported that the Argentine dictator, Jorge Rafael Videla, tried to psychologically frighten the Peruvian soccer team by entering the team's locker room, shortly before the soccer match between Peru and Argentina.
== Academic programs == Certified Nursing Assistant (CNA) Phlebotomy Technician Medical Laboratory Assistant (MLA) Patient Care Technician Certified Caregiver Assisted Living Facility Manager CPR First Aide Continuing Education for Assisted Living Caregivers and Managers
== Distinctions == Hofmann was the founder and the director of Protein Research Laboratory at the School of Medicine at University of Pittsburgh, a member of the National Academy of Sciences, Professor Emeritus of Experimental Medicine and Biochemistry at the University of Pittsburgh School of Medicine, and a member of American Association for the Advancement of Science.
Sources: en.wikipedia.org
== Management and treatment == Peyronie's disease treatment is based on stage of disease, degree of curvature, loss of function, and patient choice. Conservative management in the acute phase has the aim of reducing inflammation and disease extension.
The manufacture of antidotes called mithridate or theriac (English "treacle") continued into the nineteenth century. Ephraim Chambers, in his 1728 Cyclopaedia, says "Mithridate is one of the capital Medicines in the Apothecaries Shops, being composed of a vast Number of Drugs, as Opium, Myrrh, Agaric, Saffron, Ginger, Cinnamon, Spikenard, Frankincense, Castor, Pepper, Gentian, &c. It is accounted a Cordial, Opiate, Sudorific, and Alexipharmic". Petrus Andreas Matthiolus considered it more effectual against poisons than Venice treacle, and easier to make. Late versions of the antidote incorporated dried blood or the dried flesh of lizards or vipers or Malabathrum.
== Inhibition == The main inhibitor of tissue plasminogen activator and urokinase is plasminogen activator inhibitor-1 (PAI-1). Plasminogen activator inhibitor-1 is a serine protease, synthesized by endothelial cells, that specifically inhibits tissue plasminogen activator (tPA) and urokinase (uPA). Tissue plasminogen activator and urokinase are the activators of plasminogen and result in the breakdown of blood clots (fibrinolysis). PAI-1 levels have also been studied in patients and how they influence certain diseases. Elevated serum levels of PAI-1 have been found in obese individuals. Elevated levels of PAI-1 also seem to increase the risk of atherothrombotic events and may also promote vascular disease. Plasminogen activator inhibitor-2 (PAI-2) is a serine protease that inactivates tPA and uPA. PAI-2 is produced by the placenta and only found in high quantities in the blood during pregnancy.
=== Psychic phenomena === Reviewing Georges Charpak and Henri Broch's Debunked! ESP, Telekenesis and Other Pseudoscience, he wrote "Charpak and Broch have done a fine job sweeping out the moneypchangers from the temple of science and exposing their tricks." He went on: "The hypothesis that paranormal phenomena are real but lie outside the limits of science is supported by a great mass of evidence.. ... I find it plausible that a world of mental phenomena should exist, too fluid and evanescent to be grasped by the cumbersome tools of science. ... I am suggesting that paranormal mental abilities and scientific method may be complementary. The word 'complementarity' is a technical term introduced into physics by Niels Bohr. It means that two descriptions of nature may both be valid but cannot be observed simultaneously. The classic example of complemntarity is the dual nature of light. In one experiment light is seen to behave as a continuous wave, in another experiment it behaves as a swarm of particles, but we cannot see the wave and the particles in the same experiment. Complementarity in physics is an established fact. The extension of the idea of complementarity to mental phenomena is pure speculation. But I find it plausible." He wrote a foreword to Elizabeth Lloyd Mayer's Extraordinary Knowing, arguing "ESP is real... but cannot be tested with the clumsy tools of science".
== References == "Wife Stricken in War-Torn China, Husband Develops Own Insulin Lab". Kentucky New Era. 1951-11-06. p. 14. Mclean, Radha (2002), Eva's Insulin Hirsch, James (2006), Cheating Destiny: Living with Diabetes, America's biggest epidemic, Boston: Houghton Mifflin Co., ISBN 0-618-51461-9
Sources: en.wikipedia.org
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.
Freeze-dried material is kept frozen, often at minus 20 degrees Celsius, and protected from light and moisture. Dissolved peptide is refrigerated for short-term use. Repeated freeze-thaw cycles are avoided.
A certificate of analysis typically lists purity by HPLC, the confirmed mass, appearance, and sometimes water or counter-ion content. It documents results for a specific batch. Details vary by supplier.
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.