Tuftsin analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
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.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
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.
=== Apodization in mass spectrometry === During oscillation within an Orbitrap, a transient signal may not be stable until the ions settle into their oscillations. Toward the end, subtle ion collisions add up to cause noticeable dephasing. This presents a problem for the Fourier transform, as it averages the oscillatory signal across the length of the time-domain measurement. Software allows "apodization", the removal of the front and back section of the transient signal from consideration in the FT calculation. Thus, apodization improves the resolution of the resulting mass spectrum. Another way to improve the quality of the transient is to wait to collect data until ions have settled into stable oscillatory motion within the trap.
It is used for the treatment of anxiety and has similar effectiveness compared to diazepam. Ketazolam also appears to produce reduced levels of side effects such as sedation compared with diazepam and the side effects when they occur tend to be milder. Ketazolam is also an effective antispasmodic drug and is used for the treatment of spasticity.
The four main components of extremities are bones, vessels, nerves, and soft tissues. Gunshot wounds can thus cause severe bleeding, fractures, nerve deficits, and soft tissue damage. The Mangled Extremity Severity Score (MESS) is used to classify the severity of injury and evaluates for severity of skeletal and/or soft tissue injury, limb ischemia, shock, and age. Depending on the extent of injury, management can range from superficial wound care to limb amputation. Vital sign stability and vascular assessment are the most important determinants of management in extremity injuries. As with other traumatic cases, those with uncontrolled bleeding require immediate surgical intervention. If surgical intervention is not readily available and direct pressure is insufficient to control bleeding, tourniquets or direct clamping of visible vessels may be used temporarily to slow active bleeding. People with hard signs of vascular injury also require immediate surgical intervention. Hard signs include active bleeding, expanding or pulsatile hematoma, bruit/thrill, absent distal pulses and signs of extremity ischemia. For stable people without hard signs of vascular injury, an injured extremity index (IEI) should be calculated by comparing the blood pressure in the injured limb compared to an uninjured limb in order to further evaluate for potential vascular injury. If the IEI or clinical signs are suggestive of vascular injury, the person may undergo surgery or receive further imaging including CT angiography or conventional arteriography.
Sources: en.wikipedia.org
=== Fourth week (14–18 March) === On 14 March, the Taliban-run Afghan Ministry of Defense said that Taliban forces had captured a Pakistani border outpost, killing 14 soldiers and injuring 11 others. The ministry also added that they destroyed an armored tank and a military vehicle of Pakistani forces. However, Pakistani officials denied allegations made by Afghan Ministry of Defense, terming them false, fabricated and aimed at misleading the Afghan public. According to Pakistani officials, the damages and losses suffered by the Afghan Taliban and the Pakistani Taliban were being regularly documented, with related video and photographic evidence shared with the media. Elsewhere, Pakistani security forces killed six Pakistani Taliban militants in Lakki Marwat. Later that day, Pakistani officials stated that the Pakistan Air Force had carried out airstrikes on five military bases in Kandahar, including the General Directorate of Intelligence (GDI), Haibatullah Akhundzada's special forces unit, the border command, a tunnel, and a Taliban technical equipment warehouse. Pakistani officials added that the targeted military sites had been destroyed and released videos and images of the strikes in Kandahar. Locals in Kandahar told an Agence France-Presse journalist that military aircraft had flown over a mountain housing a military facility before an explosion was heard. Afghan locals sources state that Pakistani airstrikes struck a Taliban special forces facility linked to Hibatullah Akhundzada, as well as an ammunition depot and a border command center in Kandahar Province.
In amniotes, the clitoris ( KLIT-ər-iss or klih-TOR-iss; pl.: clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous area and generally the primary anatomical source of female sexual pleasure. The clitoris is a complex structure, and its size and sensitivity can vary. The visible portion, the glans, of the clitoris is typically roughly the size and shape of a pea and is estimated to have more than 10,000 nerve endings. Sometimes in common speech, clitoris or clit is used to solely reference the glans. Sexological, medical, and psychological debate has focused on the clitoris, and it has been subject to social constructionist analyses and studies. Such discussions range from anatomical accuracy, gender inequality, female genital mutilation, and orgasmic factors and their physiological explanation for the G-spot. The only known purpose of the human clitoris is to provide sexual pleasure. Knowledge of the clitoris is significantly affected by its cultural perceptions. Studies suggest that knowledge of its existence and anatomy is scant in comparison with that of other sexual organs (especially male sex organs) and that more education about it could help alleviate stigmas, such as the idea that the clitoris and vulva in general are visually unappealing or that female masturbation is taboo and disgraceful. The clitoris is homologous to the majority of the penis in males.
== History == Bodybuilding.com grew out of wholesale-creatine.com, an online storefront created by teenage web marketer and amateur bodybuilder Ryan DeLuca in 1997, to capitalize on the rising popularity of creatine supplements. A majority stake in Bodybuilding.com was acquired in July 2006 by Milestone Partners for an undisclosed amount. In 2007, an FDA agent purchased several supplements from Bodybuilding.com which were determined to contain anabolic steroids. In May 2012, the company was fined $7 million, and as part of the settlement, CEO DeLuca and his brother Jeremy were both fined $600,000 for selling misbranded drugs. In January 2008, Liberty Media Corporation acquired a controlling stake in Bodybuilding.com for more than $100 million. DeLuca stayed on as the company's CEO.
=== Subsequent history === In 2008, SPUSA candidate for President Brian Moore vocally opposed the idea that Barack Obama was a socialist of any kind, saying it was "misleading of the Republicans" to spread that message. In 2009, the Socialist Party of Connecticut protested in Hartford against Obama's troop surge in Afghanistan. In 2010, SPUSA Co-Chair Billy Wharton called Obama's 2010 State of the Union Address a "public relations ploy". Wharton criticized the Affordable Care Act as designed "to protect the profit margins of private insurance companies". In 2012, SPUSA member Pat Noble was elected to the Red Bank Regional High School Board of Education. Noble ran openly as a Socialist, despite the race being nonpartisan.
Sources: en.wikipedia.org
=== Journalistic opinions and investigations === Through the years, Ana Leal's investigative journalism in TVI brought new leads to Mendonça's case, always before the police. She followed leads from the Benidorm video, information from various pedophile photos from Holland and Switzerland. According to the journalist "it only has one explanation: negligence from the many teams of the Judiciary Police (...) There wasn't a political desire (..) They got followed TVI's investigations (...) it was annoying for TVI to be ahead (...) shame to a PJ team." In two photos presented in the PJ (Judiciary Police) process for a SIC report, the inspector Luís Bordadágua said that it was possible to see resemblances with Mendonça in the archives found with pedophiles. The reconnaissance was hindered due to the boy having his eyes shut in one of the photos. A Public Ministry agent alleged that the leads were fake and the PJ said later that they did not have leads to follow such a line of investigation. In another photo that Ana Leal had access to in 2002 and gave to the judiciary power, it's possible to see a gagged boy with signs of torture that the family recognized as Mendonça. With the appearance of these leads, Ricardo Sá Fernandes questioned the "worrying social passivity of the authorities of the European Union to destroy the international pedophile ring" and the "lack of capacity for investigation, mainly at a European level".
The alkali metals are more similar to each other than the elements in any other group are to each other. Indeed, the similarity is so great that it is quite difficult to separate potassium, rubidium, and caesium, due to their similar ionic radii; lithium and sodium are more distinct. For instance, when moving down the table, all known alkali metals show increasing atomic radius, decreasing electronegativity, increasing reactivity, and decreasing melting and boiling points as well as heats of fusion and vaporisation. In general, their densities increase when moving down the table, with the exception that potassium is less dense than sodium. One of the very few properties of the alkali metals that does not display a very smooth trend is their reduction potentials: lithium's value is anomalous, being more negative than the others. This is because the Li+ ion has a very high hydration energy in the gas phase: though the lithium ion disrupts the structure of water significantly, causing a higher change in entropy, this high hydration energy is enough to make the reduction potentials indicate it as being the most electropositive alkali metal, despite the difficulty of ionising it in the gas phase. The stable alkali metals are all silver-coloured metals except for caesium, which has a pale golden tint: it is one of only three metals that are clearly coloured (the other two being copper and gold).
=== Germany === A ban on absinthe was enacted in Germany on 27 March 1923. In addition to banning the production of commercial trade in absinthe, the law went so far as to prohibit the distribution of printed matter that provided details of its production. The original ban was lifted in 1981, but the use of Artemisia absinthium as a flavouring agent remained prohibited. On 27 September 1991, Germany adopted the European Community's standards of 1988, which effectively re-legalised absinthe.
== Organs and tissues affected by IGF-1 == Since many distinct tissue types express the IGF-1 receptor, IGF-1's effects are diverse. It acts as a neurotrophic factor, inducing the survival of neurons. It may catalyse skeletal muscle hypertrophy, by inducing protein synthesis, and by blocking muscle atrophy. It is protective for cartilage cells, and is associated with activation of osteocytes, and thus may be an anabolic factor for bone. Since at high concentrations it is capable of activating the insulin receptor, it can also complement for the effects of insulin. Receptors for IGF-1 are found in vascular smooth muscle, while typical receptors for insulin are not found in vascular smooth muscle.
=== Historical legality and modern-day usage in the United States === On October 24, 1968, possession of LSD was made illegal in the United States. The last FDA approved study of LSD in patients ended in 1980, while a study in healthy volunteers was made in the late 1980s. Legally approved and regulated psychiatric use of LSD continued in Switzerland until 1993. As of 2017, about 10% of people in the United States have used LSD at some point in their lives, while 0.7% have used it in the last year. The use of LSD among US adults increased by 56.4% from 2015 to 2018. In November 2020, Oregon became the first US state to decriminalize possession of small amounts of LSD after voters approved Ballot Measure 110.
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.