If you have been reading about lyophilization 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.
Last reviewed on 2026-02-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
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.
=== Pharmacokinetics === The oral activity of nandrolone has been studied. With oral administration of nandrolone in rodents, it had about one-tenth of the potency of subcutaneous injection of nandrolone. Nandrolone has very low affinity for human serum sex hormone-binding globulin (SHBG), about 5% of that of testosterone and 1% of that of DHT. It is metabolized by the enzyme 5α-reductase, among others. Nandrolone is less susceptible to metabolism by 5α-reductase and 17β-hydroxysteroid dehydrogenase than testosterone. This results in it being transformed less in so-called "androgenic" tissues like the skin, hair follicles, and prostate gland and in the kidneys, respectively. Metabolites of nandrolone include 5α-dihydronandrolone, 19-norandrosterone, and 19-noretiocholanolone, and these metabolites may be detected in urine. Single intramuscular injections of 100 mg nandrolone phenylpropionate or nandrolone decanoate have been found to produce an anabolic effect for 10 to 14 days and 20 to 25 days, respectively. Conversely, unesterified nandrolone has been used by intramuscular injection once daily.
== See also == Wafer-scale integration – System of building very large integrated circuit networks Wafer-level packaging – Means of packaging an integrated circuit Semiconductor device fabrication – Manufacturing process used to create integrated circuits Transistor count – Number of transistors in a device Comparison of deep learning software – Tabular comparison of deep learning software Neural processing unit – Hardware acceleration unit for artificial intelligence tasks Outline of deep learning – Overview of and topical guide to deep learning
In MM2K Phillips highly endorsed MET-Rx (a meal replacement supplement), and this relationship with readers helped it become the highest selling bodybuilding supplement ever at that time. It was later revealed however, that Phillips and the creator of MET-Rx, Dr. A. Scott Connelly, were in fact business partners, and the endorsements clever marketing. This partnership also included bodybuilders Lee Labrada and Jeff Everson. It was around this time that Phillips began working with James Bradshaw (later of SoCal Supplements). Bradshaw was convicted of dispensing human and animal steroids without prescriptions in 1986. This eventually would lead to Bradshaw serving four years in a Louisiana prison, where he educated himself on marketing. According to former Muscle Media 2000 editor-in-chief TC Luoma, it was Bradshaw who convinced Phillips to market MET-Rx heavily in the Natural Supplement Review, Phillips' supposedly unbiased review of numerous bodybuilding supplements. He also had the idea for Phillips to give the Review away for free to readers of Muscle Media 2000, thus obtaining the addresses of potential MET-Rx buyers and toward which a large amount of advertising may be targeted. Sales of MET-Rx rose exponentially. Bradshaw and Phillips had stumbled upon a very successful method of marketing to bodybuilders, and they, and original investors Everson and Connelly, got very wealthy. Their partnership was short-lived however.
Sources: en.wikipedia.org
== External links == Clinical trial number (NCT05656027 for "Phase 3 Evaluation of the Safety and Efficacy of LNZ101 for the Treatment of Presbyopia (CLARITY)" at ClinicalTrials.gov Clinical trial number (NCT05728944 for "Phase 3 Efficacy Study of LNZ101 for the Treatment of Presbyopia (CLARITY)" at ClinicalTrials.gov Clinical trial number (NCT05753189 for "Phase 3 Safety Study for the Treatment of Presbyopia Subjects" at ClinicalTrials.gov
Pu-239 (also known as The Half Life of Timofey Berezin) is a 2006 British drama film written and directed by Hollywood producer Scott Z. Burns in his feature directorial debut, which was based on the book Pu-239 and Other Russian Fantasies written by Ken Kalfus. The film was shown twice at the 2006 Toronto International Film Festival under the title The Half Life of Timofey Berezin before being distributed by HBO Films under its original working title. Pu-239 is the chemical symbol for plutonium-239 (239Pu), the most readily fissile isotope of the element plutonium.
=== Biofuels, pharmaceuticals and biomaterials === The most popular biofuel is ethanol produced from corn or sugar cane, but this method of producing biofuels is troublesome and constrained due to the high agricultural cost and inadequate fuel characteristics of ethanol. A substitute and potential source of renewable energy is microbes that have had their metabolic pathways altered to be more efficient at converting biomass into biofuels. Only if their production costs could be made to match or even beat those of present fuel production can these techniques be expected to be successful. Related to this, there are several medicines whose pricey manufacturing procedures prevent them from having a larger therapeutic range. The creation of new materials and the microbiological manufacturing of biomaterials would both benefit substantially from novel artificial biology tools.
Sources: en.wikipedia.org
=== Mosaic Viruses === In 1955, Robert Rice and Kaesberg researched why the tobacco mosaic virus breaks apart after preservation via freeze-drying. Although they did not figure out what caused it specifically, their research allowed them to rule out several possibilities. They found that the act of freeze-drying did not cause the virus to break, as freeze-drying did not cause insulin fibrils or flagella to break. In 1956, Kaesberg discovered a new virus shape, the icosahedral shape. After taking electron micrographs of the bromegrass mosaic virus and the yellow turnip mosaic virus under light shadowing and heavy shadowing, respectfully, Kaesberg was able to come up with an icosahedral model of the viruses. This shape became the modern-day symbol for a virus because, after much more research, the icosahedral shape was one of the most commonly found virus shapes. In 1958, Kaesberg and colleagues discovered a mosaic virus found in alfalfa creates three macromolecules after infecting a plant. Only one of the types of particles produced the virus, but all three had a similar bacillus-like shape and size. These particles looked nothing like the known spherical species of the alfalfa mosaic virus, so they discovered a new isolate in their work. In 1964, Paul Kaesberg and a colleague studied the effects of pH changes on the bromegrass mosaic virus. They found that when the environment's pH is higher than 6.7, there is a decrease in the virus’ sedimentation coefficient. The coefficient goes back up if the pH goes below 6.7.
IND stands for Investigational New Drug application, which is part of the process to get approval from the FDA for marketing a new prescription drug in the U.S. It makes promising new drugs available to desperately ill participants as early in the drug development process as possible. Treatment INDs are made available to participants before general marketing begins, typically during Phase III studies. To be considered for a treatment IND a participant cannot be eligible to be in the definitive clinical trial. (NLM) Treatment trials
Homozygous or compound heterozygous mutations are therefore likely subject to differential regulation depending on whether they are double missense, double truncating or mixed missense/truncating mutations. The homozygous Mybpc3-targeted knock-in mice, which genetically mimic the situation of severe neonatal cardiomyopathy are born without phenotype and soon after birth develop systolic dysfunction followed by (compensatory) cardiac hypertrophy. The human c.772G>A transition results in low levels of three different mutant Mybpc3 mRNAs and cMyBP-Cs in homozygous mice, suggesting a combination of haploinsufficiency and polypeptide poisoning as disease mechanism in the homozygous state. In addition, the combination of external stress (such as neurohumoral stress or aging) and Mybpc3 mutations have been shown to impair the UPS in mice, and proteasomal activities were also depressed in patients with hypertrophic cardiomyopathy or dilated cardiomyopathy. Skinned trabeculae or cardiac myocytes obtained from human patients carrying a MYBPC3 mutation or from heterozygous and homozygous Mybpc3-targeted knock-in mice exhibited higher myofilament Ca2+ sensitivity than controls. Disease-modeling by engineered heart tissue (EHT) technology with cardiac cells from heterozygous or homozygous Mybpc3-targeted knock-in mice reproduced observations made in human and mouse studies displaying abbreviated contractions, greater sensitivity to external Ca2+ and smaller inotropic responses to various drugs (isoprenaline, EMD 57033 and verapamil) compared to wild-type control EHTs.
=== Regulation === In order to ensure proper functioning, Wnt signaling is constantly regulated at several points along its signaling pathways. For example, Wnt proteins are palmitoylated. The protein porcupine mediates this process, which means that it helps regulate when the Wnt ligand is secreted by determining when it is fully formed. Secretion is further controlled with proteins such as GPR177 (wntless) and evenness interrupted and complexes such as the retromer complex. Upon secretion, the ligand can be prevented from reaching its receptor through the binding of proteins such as the stabilizers Dally and glypican 3 (GPC3), which inhibit diffusion. In cancer cells, both the heparan sulfate chains and the core protein of GPC3 are involved in regulating Wnt binding and activation for cell proliferation. Wnt recognizes a heparan sulfate structure on GPC3, which contains IdoA2S and GlcNS6S, and the 3-O-sulfation in GlcNS6S3S enhances the binding of Wnt to the heparan sulfate glypican. A cysteine-rich domain at the N-lobe of GPC3 has been identified to form a Wnt-binding hydrophobic groove including phenylalanine-41 that interacts with Wnt. Blocking the Wnt binding domain using a nanobody called HN3 can inhibit Wnt activation. At the Fz receptor, the binding of proteins other than Wnt can antagonize signaling. Specific antagonists include Dickkopf (Dkk), Wnt inhibitory factor 1 (WIF-1), secreted Frizzled-related proteins (SFRP), Cerberus, Frzb, Wise, SOST, and Naked cuticle. These constitute inhibitors of Wnt signaling. However, other molecules also act as activators.
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.