pharmacokinetics is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-08-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
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.
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.
I was holding excerpts (photocopies were not so accessible then) from the author's certificate USSR № 1247973 to which I have referred in all my works on the Orbitrap™ analyzer since then." Alexander Makarov's effort in commercializing Orbitrap analyzer at the end of the 1990s required a number of innovations such as image current detection, C-trap for ion injection, and other technology improvements which resulted in the commercial introduction of this analyzer by Thermo Fisher Scientific as a part of the hybrid LTQ Orbitrap instrument in 2005.
However, later on, within a more complex cellular environment, these highly hydrophobic LCRs became inappropriate or even toxic from a protein interaction perspective and have been selected against ever since. In addition, they further hypothesize that the very early protopeptides did not have a nucleic acid binding role, because DNA and RNA-binding LCRs are highly enriched in glycine, arginine and lysine, however, arginine and lysine are not among the amino acids of the proposed early genetic code.
ICP-MS is more suitable for this application than the previously used thermal ionization mass spectrometry, as species with high ionization energy such as osmium and tungsten can be easily ionized. For high precision ratio work, multiple collector instruments are normally used to reduce the effect noise on the calculated ratios. In the field of flow cytometry, a new technique uses ICP-MS to replace the traditional fluorochromes. Briefly, instead of labelling antibodies (or other biological probes) with fluorochromes, each antibody is labelled with a distinct combinations of lanthanides. When the sample of interest is analysed by ICP-MS in a specialised flow cytometer, each antibody can be identified and quantitated by virtue of a distinct ICP "footprint". In theory, hundreds of different biological probes can thus be analysed in an individual cell, at a rate of ca. 1,000 cells per second. Because elements are easily distinguished in ICP-MS, the problem of compensation in multiplex flow cytometry is effectively eliminated. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful technique for the elemental analysis of a wide variety of materials encountered in forensic casework. (LA-ICP-MS) has already successfully been applied to applications in forensics, metals, glasses, soils, car paints, bones and teeth, printing inks, trace elemental, fingerprint, and paper. Among these, forensic glass analysis stands out as an application for which this technique has great utility to provide highly.
Thyroid-stimulating hormone (TSH or thyrotropin) – stimulates the thyroid gland to make and release thyroid hormone. Adrenocorticotropic hormone (ACTH or corticotropin) – stimulates the adrenal cortex to release glucocorticoids. Luteinizing hormone (LH) – stimulates the release of steroid hormones in gonads—the ovary and testes. Follicle-stimulating hormone (FSH) – stimulates the maturation of eggs and production of sperm.
Sources: en.wikipedia.org
== Further reading == Payne M.G., Hurst G.S. (1985) Theory of Resonance Ionization Spectroscopy. In: Martellucci S., Chester A.N. (eds) Analytical Laser Spectroscopy. NATO ASI Series (Series B: Physics), vol 119. Springer, Boston, MA. Parks J.E., Young J.P. (2000) Resonance Ionization Spectroscopy 2000: Laser Ionization and Applications Incorporating RIS; 10th International Symposium, Knoxville, Tennessee (AIP Conference Proceedings).
PfSPZ Vaccine is a metabolically active non-replicating whole sporozoite (SPZ) malaria vaccine being developed by Sanaria against Plasmodium falciparum (Pf) malaria. Clinical trials have been safe, extremely well tolerated and highly efficacious. The first generation PfSPZ product is attenuated by gamma irradiation; the second generation vaccines PfSPZ-CVac and PfSPZ LARC2 are, respectively, attenuated chemically and genetically. Multiple studies are ongoing with trials of the PfSPZ vaccines. All three products are produced using the same manufacturing process. These products are stored and distributed below -150 °C using liquid nitrogen (LN2) vapor phase (LNVP) freezers and cryoshippers.
=== Sustainability === Food engineering has negative impacts on the environment, such as the emission of large quantities of waste and the pollution of water and air, which must be addressed by food engineers in the future development of food production and processing operations. Scientists and engineers are experimenting in different ways to create improved processes that reduce pollution, but these must continue to be improved in order to achieve a sustainable food supply chain. Food engineers must reevaluate current practices and technologies to focus on increasing productivity and efficiency, while reducing the consumption of water and energy, and decreasing the amount of waste produced.
== Availability == Many insulin analogs and GLP-1 agonists for diabetes treatment are available as injector pens. As with insulin vials, some insulin pens are made with higher concentrations including U-200, U-300, and U-500. Different concentration insulin products may not have the same pharmacokinetic properties as other strengths. The higher concentrations are used to lessen the volume of the injection, and allow the same dose of insulin to be injected with less force. In some cases, these medications may be combined into one pen to be administered daily, for example insulin degludec with liraglutide and insulin glargine with lixisenatide. Combination products are available in fixed-dose ratios and are generally dosed by units of insulin, which will administer a proportional amount of the GLP-1 agonist as well. Another class of medication commonly available as an injector pen is monoclonal antibodies. Due to the molecular size of monoclonal antibodies, they must be administered via injection. Examples of monoclonal antibodies available or studied as injector pens include adalimumab, secukinumab, and alirocumab. CGRP antagonists which are monoclonal antibodies, used for the prevention of migraines, are also available as injector pens. Other monoclonal antibodies designed for home use may also be manufactured as injector pens. Some medications are formulated as injector pens to quicken the onset of action of the medication. This includes epinephrine, which when used to treat anaphylaxis must work as soon as possible.
== Gender in traditional medicine == Fuke (妇科; 婦科; Fùkē) is the traditional Chinese term for women's medicine (it means gynecology and obstetrics in modern medicine). However, there are few or no ancient works on it except for Fu Qingzhu's Fu Qingzhu Nu Ke (Fu Qingzhu's Gynecology 傅青主女科), with "Nu Ke" literally meaning "Women studies", much like the etymology of gynecology. In traditional China, as in many other cultures, the health and medicine of female bodies was less understood than that of male bodies. Women's bodies were often secondary to male bodies, since women were thought of as the weaker, sicklier sex. In clinical encounters, women and men were treated differently. Diagnosing women was not as simple as diagnosing men. First, when a woman fell ill, an appropriate adult man was to call the doctor and remain present during the examination, for the woman could not be left alone with the male doctor. The physician would discuss the female's problems and diagnosis only through the male. However, in certain cases, when a woman dealt with complications of pregnancy or birth, older women assumed the role of the formal authority. Men in these situations would not have much power to interfere. Second, women were often silent about their issues with doctors due to the societal expectation of female modesty when a male figure was in the room. Third, patriarchal society also caused doctors to call women and children patients "the anonymous category of family members (Jia Ren) or household (Ju Jia)" in their journals.
Sources: en.wikipedia.org
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.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.