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.
Updated 2026-05-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
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.
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.
== Other animals == Rhabdomyolysis is recognized in horses. Horses can develop several muscle disorders, many of which may progress to rhabdomyolysis. Of these, some cause isolated attacks of rhabdomyolysis (e.g., dietary deficiency in vitamin E and selenium, poisoning associated with pasture or agricultural poisons such as organophosphates), while others predispose to exertional rhabdomyolysis (e.g., the hereditary condition equine polysaccharide storage myopathy). Of thoroughbred horses, 5–10% and some standardbred horses have the condition equine exertional rhabdomyolysis; no specific cause has been identified, but an underlying muscle calcium regulation disorder is suspected. Rhabdomyolysis affecting horses may also occur in outbreaks; these have been reported in many European countries, and later in Canada, Australia, and the United States. It has been referred to as "atypical myopathy" or "myoglobinuria of unknown etiology". No single cause has yet been found, but various mechanisms have been proposed, and a seasonal pattern has been observed. Very high creatine kinase levels are detected, and mortality from this condition is 89%.
In early April, Sykes and Picot were appointed to act as the chief negotiators once more, this time on a month-long mission to the Middle East for further discussions with the Sherif of Mecca and other Arab leaders. On 3 April 1917, Sykes met with Lloyd George, Lord Curzon and Maurice Hankey to receive his instructions in this regard, namely to keep the French onside while "not prejudicing the Zionist movement and the possibility of its development under British auspices, [and not] enter into any political pledges to the Arabs, and particularly none in regard to Palestine". Before travelling to the Middle East, Picot, via Sykes, invited Nahum Sokolow to Paris to educate the French government on Zionism. Sykes, who had prepared the way in correspondence with Picot, arrived a few days after Sokolow; in the meantime, Sokolow had met Picot and other French officials, and convinced the French Foreign Office to accept for study a statement of Zionist aims "in regard to facilities of colonization, communal autonomy, rights of language and establishment of a Jewish chartered company." Sykes went on ahead to Italy and had meetings with the British ambassador and British Vatican representative to prepare the way for Sokolow once again. Sokolow was granted an audience with Pope Benedict XV on 6 May 1917. Sokolow's notes of the meeting – the only meeting records known to historians – stated that the Pope expressed general sympathy and support for the Zionist project.
The illegal trade for tiger parts in China has driven the species to near-extinction because of its popularity in traditional medicine. Laws protecting even critically endangered species such as the Sumatran tiger fail to stop the display and sale of these items in open markets. Shark fin soup is traditionally regarded in Chinese medicine as beneficial for health in East Asia, and its status as an elite dish has led to huge demand with the increase of affluence in China, devastating shark populations. The shark fins have been a part of traditional Chinese medicine for centuries. Shark finning is banned in many countries, but the trade is thriving in Hong Kong and China, where the fins are part of shark fin soup, a dish considered a delicacy, and used in some types of traditional Chinese medicine. Restrictions are made on the accumulation and export of endangered species not raised in captivity. Australian scientists have developed methods to identify medicines containing DNA traces of endangered species. Finally, although not an endangered species, sharp rises in exports of donkeys and donkey hide from Africa to China to make the traditional remedy ejiao have prompted export restrictions by some African countries.
Sources: en.wikipedia.org
=== Availability === Ketoconazole is available widely throughout the world. In 2013, the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) recommended that a ban be imposed on the use of oral ketoconazole for systemic use in humans throughout the European Union, after concluding that the risk of serious liver injury from systemic ketoconazole outweighs its benefits.
4-nitrophenol 4-monooxygenase (EC 1.14.13.167, pnpA (gene), pdcA (gene)) is an enzyme with systematic name 4-nitrophenol,NAD(P)H:oxygen 4-oxidoreductase (4-hydroxylating, nitrite-forming). This enzyme catalyses the following chemical reaction
There is controversy over GMOs, especially with regard to their release outside laboratory environments. The dispute involves consumers, producers, biotechnology companies, governmental regulators, non-governmental organizations, and scientists. Many of these concerns involve GM crops and whether food produced from them is safe and what impact growing them will have on the environment. These controversies have led to litigation, international trade disputes, and protests, and to restrictive regulation of commercial products in some countries. Most concerns are around the health and environmental effects of GMOs. These include whether they may provoke an allergic reaction, whether the transgenes could transfer to human cells, and whether genes not approved for human consumption could outcross into the food supply.
Sources: en.wikipedia.org
Since 2019, Schleip has been a professor of conservative and rehabilitative orthopaedics in the Department of Sport and Health Sciences at the Technical University of Munich, and a faculty member at the Diploma University of Applied Sciences. In 2023, he was appointed as a professor of health and psychology at the Diploma University of Applied Sciences.
=== Dynamics === Action potentials are most commonly initiated by excitatory postsynaptic potentials from a presynaptic neuron. Typically, neurotransmitter molecules are released by the presynaptic neuron. These neurotransmitters then bind to receptors on the postsynaptic cell. This binding opens various types of ion channels. This opening has the further effect of changing the local permeability of the cell membrane and, thus, the membrane potential. If the binding increases the voltage (depolarizes the membrane), the synapse is excitatory. If, however, the binding decreases the voltage (hyperpolarizes the membrane), it is inhibitory. Whether the voltage is increased or decreased, the change propagates passively to nearby regions of the membrane (as described by the cable equation and its refinements). Typically, the voltage stimulus decays exponentially with the distance from the synapse and with time from the binding of the neurotransmitter. Some fraction of an excitatory voltage may reach the axon hillock and may (in rare cases) depolarize the membrane enough to provoke a new action potential. More typically, the excitatory potentials from several synapses must work together at nearly the same time to provoke a new action potential. Their joint efforts can be thwarted, however, by the counteracting inhibitory postsynaptic potentials. Neurotransmission can also occur through electrical synapses. Due to the direct connection between excitable cells in the form of gap junctions, an action potential can be transmitted directly from one cell to the next in either direction.
=== Diplomats === Hamzat Ahmadu - Nigerian diplomat, former ambassador to the Soviet Union, the United States of America and high commissioner to the Bahamas. Nuhu Bamalli - Former minister of foreign affairs Mohammed Sanusi Barkindo – 28th Secretary-General of OPEC. Ibrahim Gambari – (Fulani/Yoruba); Scholar and diplomat; Chief of Staff to the president; Under-Secretary-General / Special Adviser – Africa United Nations; former minister of foreign affairs, current chief of staff to the president of Nigeria. Amina J. Mohammed – (Fulani/English); Politician; Deputy Secretary-General of the United Nations; former Federal Minister of Environment, Nigeria. Tijjani Muhammad-Bande – Political scientist, administrator and career diplomat. Current president of the United Nations General Assembly, Permanent Representative of Nigeria to the UN, former VP of the UN General Assembly. Nura Abba Rimi - Nigeria's ambassador to the Arab Republic of Egypt, with concurrent accreditation to the State of Palestine and the State of Eritrea; former Presidential Liaison Officer. Ibrahim Sulu-Gambari – (Fulani/Yoruba); Nigerian judge and monarch. Current Emir of Ilorin, Nigeria. Yusuf Tuggar – Minister of Foreign Affairs. Aminu Bashir Wali - Former permanent representative to the United Nations, former minister of foreign affairs. Isa Wali - former Nigerian high commissioner to Ghana.
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.