If you have been reading about Neurotrophic factor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-10-03. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
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.
In 1927, Max Oberlin studied the pharmacology of MDMA while searching for substances with effects similar to adrenaline or ephedrine, the latter being structurally similar to MDMA. Compared to ephedrine, Oberlin observed that it had similar effects on vascular smooth muscle tissue, stronger effects at the uterus, and no "local effect at the eye". MDMA was also found to have effects on blood sugar levels comparable to high doses of ephedrine. Oberlin concluded that the effects of MDMA were not limited to the sympathetic nervous system. Research was stopped "particularly due to a strong price increase of safrylmethylamine", which was still used as an intermediate in methylhydrastinine synthesis. Albert van Schoor performed simple toxicological tests with the drug in 1952, most likely while researching new stimulants or circulatory medications. After pharmacological studies, research on MDMA was not continued. In 1959, Wolfgang Fruhstorfer synthesized MDMA for pharmacological testing while researching stimulants. It is unclear if Fruhstorfer investigated the effects of MDMA in humans. Outside of Merck, other researchers began to investigate MDMA. In 1953 and 1954, the United States Army commissioned a study of toxicity and behavioral effects in animals injected with mescaline and several analogues, including MDMA. Conducted at the University of Michigan in Ann Arbor, these investigations were declassified in October 1969 and published in 1973.
== Function == LepA is suspected to improve the fidelity of translation by recognizing a ribosome with mistranslocated tRNA and consequently inducing a back-translocation. By back-translocating the already post-transcriptionally modified ribosome, the EF-G factor capable of secondary translocation. Back-translocation by LepA occurs at a similar rate as an EF-G-dependent translocation. As mentioned above, EF-G's structure is highly analogous to LepA's structure; LepA's function is thus similarly analogous to EF-G's function. However, Domain IV of EF-G has been shown through several studies to occupy the decoding sequence of the A site after the tRNAs have been translocated from A and P sites to the P and E sites. Thus, domain IV of EF-G prevents back-movement of the tRNA. Despite the structural similarities between LepA and EF-G, LepA lacks this Domain IV. Thus LepA reduces the activation barrier between Pre and POST states in a similar way to EF-G but is, at the same time, able to catalyze a back-translocation rather that a canonical translocation.
Crystallography is a technique that characterizes the chemical structure of materials at the atomic level by analyzing the diffraction patterns of electromagnetic radiation or particles that have been deflected by atoms in the material. X-rays are most commonly used. From the raw data, the relative placement of atoms in space may be determined.
Albany calls itself the "rare metals capital of the world", producing zirconium, hafnium and titanium. One of the major producers of these metals in Albany is ATI Specialty Alloys and Components (formerly ATI Wah Chang) which has a 110-acre (0.45 km2) site that primarily focuses on the production of zirconium. Albany and the surrounding communities are major exporters of grass seed. Other crops produced include corn, beans, mint, strawberries, and hazelnuts. Linn County is also referred to as the "Grass Seed Capital of the World". Albany is the headquarters of Coastal Farm & Ranch, a chain of farm supply stores in the Pacific Northwest. The decline of the timber industry and the outsourcing of manufacturing jobs has left Linn County with a relatively high unemployment rate. The Oregon Employment Department does not maintain unemployment statistics for cities. The losses in the timber industry in the region around Albany have led the city to a more diverse economic base for the city, led by retail trade, health care and social assistance, and manufacturing as the three leading aspects of the economy. Oregon Freeze Dry is a leading employer in the manufacturing sector of the Albany economy with its headquarters located in the city. The company employs over 300 people and was incorporated in 1963.
Sources: en.wikipedia.org
== Mechanisms of action and effects == There are many different mechanisms through which steroid hormones affect their target cells. All of these different pathways can be classified as having either a genomic effect or a non-genomic effect. Genomic pathways are slow and result in altering transcription levels of certain proteins in the cell; non-genomic pathways are much faster.
A thermal shift assay (TSA) measures the stability of a protein by the change in its thermal denaturation temperature. This is done under varying conditions, such as variations in drug concentration, buffer formulation (pH or ionic strength), redox potential, or sequence mutation. The most common method for measuring protein thermal shifts is differential scanning fluorimetry (DSF). DSF methodology includes techniques such as nanoDSF, which relies on the intrinsic fluorescence from native tryptophan or tyrosine residues, and Thermofluor, which utilizes extrinsic fluorogenic dyes. The binding of low molecular weight ligands can increase the thermal stability of a protein, as described by Daniel Koshland (1958) and Kaj Ulrik Linderstrøm-Lang and Schellman (1959). Almost half of enzymes require a metal ion co-factor. Thermostable proteins are often more useful than their non-thermostable counterparts, e.g., DNA polymerase in the polymerase chain reaction, so protein engineering often includes adding mutations to increase thermal stability. Protein crystallization is more successful for proteins with a higher melting point and adding buffer components that stabilize proteins improve the likelihood of protein crystals forming. If examining pH then the possible effects of the buffer molecule on thermal stability should be taken into account along with the fact that pKa of each buffer molecule changes uniquely with temperature. Additionally, any time a charged species is examined the effects of the counterion should be accounted for.
Miraculin, is a glycoprotein extracted from Synsepalum dulcificum a berry which alters human tongue receptors to recognize sour foods as sweet. Variable surface glycoproteins allow the sleeping sickness Trypanosoma parasite to escape the immune response of the host. The viral spike of the human immunodeficiency virus is heavily glycosylated. Approximately half the mass of the spike is glycosylation and the glycans act to limit antibody recognition as the glycans are assembled by the host cell and so are largely 'self'. Over time, some patients can evolve antibodies to recognise the HIV glycans and almost all so-called 'broadly neutralising antibodies (bnAbs) recognise some glycans. This is possible mainly because the unusually high density of glycans hinders normal glycan maturation and they are therefore trapped in the premature, high-mannose, state. This provides a window for immune recognition. In addition, as these glycans are much less variable than the underlying protein, they have emerged as promising targets for vaccine design. P-glycoproteins are critical for antitumor research due to its ability block the effects of antitumor drugs. P-glycoprotein, or multidrug transporter (MDR1), is a type of ABC transporter that transports compounds out of cells. This transportation of compounds out of cells includes drugs made to be delivered to the cell, causing a decrease in drug effectiveness. Therefore, being able to inhibit this behavior would decrease P-glycoprotein interference in drug delivery, making this an important topic in drug discovery.
The same month, she collaborated with Trainline and attended King's Cross Station to promote their "Slaystation" service, a pop-up experience where commuters were able to get their hair and make-up done. In July 2025, Collins appeared in an online advertisement campaign for Sky Mobile, for which she fronted a satire video apologising about accidentally "oversharing" details about her wedding, before revealing she was "not sorry" and subsequently endorsed them for allowing users of the network to share their mobile data. As part of the partnership, Collins said "Oversharing is caring huns, don't stress about it – I've overshared all my life and I love it. Now with Sky Mobile, we can share even more – by gifting data so that those you love can keep the group chats going strong!" In October 2025, Collins starred in an advertisement for the gambling company Paddy Power alongside Danny Dyer and Coleen Rooney, in which Collins makes her way through a casino calling after Dyer, referencing her famous meme exclaiming "I'm claustrophobic Danny" before telling Rooney to "have a day off hun". In November 2025, Collins collaborated with the online retail service AliExpress as part of their "See the Signs 11.11" campaign, which saw her attend a pop-up event in Soho where she partook in a live stream and assisted with the promotion of their products, as well as selecting a random winner to receive a giant Labubu. In February 2026, Collins collaborated with the proprietary software company Canva.
MGM-15, also known as dihydro-7-hydroxy mitragynine, DH-7OH-MIT is an opioid drug which is a semi-synthetic derivative of 7-hydroxymitragynine, a natural product derived from the Southeast Asian tree kratom. MGM-15 was first reported in 2014. It is the 1,2-dihydro derivative of 7-hydroxymitragynine and shows higher potency as an agonist of the μ-opioid receptor and δ-opioid receptor compared to 7-hydroxymitragynine itself. MGM-15 has been sold as a designer drug since early 2025, initially in the US.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
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.