This is a working overview of BDNF expression, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-14 and is reviewed periodically as new material appears.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
| Property | Value | Notes |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
=== Occlusion and hydration === Silicone gel sheets occlude and hydrate the stratum corneum of the treated skin area. The stratum corneum normally conserves water and acts as a barrier to microbial infection. Its function can be disrupted by wound formation. The stratum corneum of hypertrophic scars and keloids absorbs more water than normal skin, depleting the water supply from the stratum corneum. Excessive dehydration of keratinocytes stimulates cytokine production, leading to increased collagen production. After applying the sheet, the rate of water loss via evaporation of the treated skin area is half of the untreated area. Therefore, the sheet prevents the drying up of stratum corneum, and thus further collagen production. Collagen production exacerbates the growth of hypertrophic scars and keloids and thus should be avoided. Hydrating a scar over a prolonged period can also relieve symptoms such as itching and pain. Such an effect is likely due to decreased capillary activity and thus local collagen deposition.
The petition seeks to have the risk of serious sexual side effects persisting after discontinuation mentioned in the product labels of SSRIs and SNRIs. The lawsuit was dismissed by the United States District Court for the District of Columbia on March 25, 2025, due to the plaintiff lacking legal standing, as the court found no specific informational or physical injury. The FDA has not mandated comprehensive PSSD warnings across all SSRI and SNRI labels, though fluoxetine (Prozac) has included a warning about persistent sexual side effects since 2011. Most other SSRI and SNRI labels address sexual dysfunction during use but not explicitly after discontinuation.
== Medical uses == Imetelstat is indicated for the treatment of adults with low- to intermediate-1 risk myelodysplastic syndromes with transfusion-dependent anemia requiring four or more red blood cell units over eight weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents.
=== Venezuela === Bolivarian Chavismo and its supporters have declared their contempt for the Peruvian government for, according to then-Venezuelan Foreign Minister Delcy Rodríguez in 2017, supporting "Venezuela's intervention in the world" due to the creation of the Lima Group. It has also been increased by the Venezuelan authorities, such as President Nicolás Maduro describing Peru as having an "imperialist mentality" and "lifelong anti-Bolivarian" for not being invited to the VIII Summit of the Americas held in Lima due to the crisis in Venezuela. Likewise, during the Peruvian Immigration in Venezuela, many Peruvians, as well as Ecuadorians and Colombians, were subjected to discrimination and xenophobia by the Venezuelan socialist government, who used the adjectives "Indian" and "guajiro" to refer to immigrants from these countries. Anti-Peruvianism has also intensified in the Venezuelan population, which has a negative perspective against Peruvians due to accusations of xenophobia during Venezuelan Immigration in Peru, and which has generated a belief that Peruvians have been ungrateful to Venezuela after welcome them during the Peruvian exodus from the time of terrorism. Many anti-Peruvian prejudices and stereotypes have also been shown among Venezuelans, where they accuse Peruvians of being ugly people and the face of Indians, affirming that their migrants come to "improve the race". It is also often accused that figures of the Venezuelan government have had anti-Peruvian tendencies, and some historical figures of the colonial era, being some such as:
The periwound (also peri-wound) is tissue surrounding a wound. Periwound area is traditionally limited to 4 cm outside the wound's edge but can extend beyond this limit if outward damage to the skin is present. Periwound assessment is an important step of wound assessment before wound treatment is prescribed.
Sources: en.wikipedia.org
==== Extrusion-based printing ==== Although there are different approaches to extrusion based printing, these approaches follow the same basic procedures. The platform on which food is printed consists of a standard 3-axis stage with a computer controlled extrusion head. This extrusion head pushes food materials through a nozzle typically by way of compressed air or squeezing. The nozzles can vary with respect to what type of food is being extruded or the desired printing speed (typically the smaller the nozzle the longer the food printing will take). As the food is printed, the extrusion head moves along the 3-axis stage printing the desired food. Some printed food requires additional processing such as baking or frying before consumption. Extrusion based food printers can be purchased for household use, are typically compact in size, and have a low maintenance cost. Comparatively, extrusion based printing provides the user with more material choices. However, these food materials are usually soft, and as a result, makes printing complex food structures difficult. In addition, long fabrication times and deformations due to temperature fluctuations with additional baking or frying require further research and development to overcome.
=== Fatty liver disease === Studies in mice have shown that activation of FFAR3 by short-chain fatty acids (SC-FAs) suppresses liver lipid synthesis, reduces triglyceride accumulation, and decreases liver weight in models of diet-induced obesity. Mice lacking the Ffar3 gene fail to exhibit these protective effects, suggesting a critical role for FFAR3 in preventing excessive hepatic fat accumulation. These findings support further research to determine whether FFAR3 functions similarly in humans and whether FFAR3 activators could be developed as potential treatments for human fatty liver diseases, including non-alcoholic fatty liver disease.Koh A, De Vadder F, Kovatcheva-Datchary P, Bäckhed F (June 2016). "From Dietary Fiber to Host Physiology: Short-Chain Fatty Acids as Key Bacterial Metabolites". Cell. 165 (6): 1332–1345. doi:10.1016/j.cell.2016.05.041. PMID 27259147. S2CID 8562345.
=== 2000s === 2000: Venezuelan astrophysicist Kathy Vivas presented her discovery of approximately 100 "new and very distant" RR Lyrae stars, providing insight into the structure and history of the Milky Way galaxy. 2000: Russian gynaecologist Galina Savelyeva founded the Department of Obstetrics and Gynaecology at Moscow State University. Savelyeva was one of the first scientists in the world to demonstrate the feasibility of using craniocerebral hypothermia in the treatment of babies born with asphyxia, which formed the basis for the Russian Ministry of Health's order on the primary resuscitation of babies born with asphyxia. 2001: Danish physicist Lene Hau led a Harvard University team who used a Bose–Einstein condensate to slow down a beam of light to about 17 metres per second, then were able to stop a beam completely. 2003: Danish structural chemist and crystallographer Sine Larsen became the first female scientific research director at the European Synchrotron Radiation Facility (ESRF), where she was responsible for research in the fields of structural biology and structural chemistry. 2003: American geophysicist Claudia Alexander oversaw the final stages of Project Galileo, a space exploration mission that ended at the planet Jupiter. 2004: American biologist Linda B. Buck received the Nobel Prize in Physiology or Medicine along with Richard Axel "for their discoveries of odorant receptors and the organization of the olfactory system". 2004: American astrophysicist and radio astronomer Naomi McClure-Griffiths identified a new spiral arm of the Milky Way galaxy.
=== Ber–Bla === Paul Berg (1926–2023), American biochemist known for research on nucleic acids, especially recombinant DNA, 1980 Nobel Prize in Chemistry Friedrich Bergius (1884–1949), German chemist known for known for production of synthetic fuel from coal, 1931 Nobel Prize in Chemistry Helen M. Berman (born 1943), American chemist who worked on structural analysis of protein-nucleic acid complexes Marcellin Berthelot (1827–1907), French chemist, a prominent anti-vitalist who synthesized many organic compounds from inorganic substances, and developed thermochemistry Claude Louis Berthollet (1748–1822), French chemist who developed the theory of chemical equilibria Carolyn R. Bertozzi (born 1966) American chemist who studies chemical reactions compatible with living systems ("bioorthogonal chemistry"), 2022 Nobel Prize in Chemistry Guy Bertrand (born 1952) French chemist working on carbenes, nitrenes, phosphinidenes, radicals and biradicals Jöns Jakob Berzelius (1779–1848), Swedish chemist who discovered several elements Johannes Martin Bijvoet (1892–1980), Dutch chemist and crystallographer who determined the absolute configuration of sodium rubidium tartrate Leonora Bilger (1893–1975), American chemist who studied nitrogenous compounds Katherine Bitting (1869–1937), Canadian and American food chemist for the United States Department of Agriculture and the National Canners Association Joseph Black (1728–1799), British chemist known for discoveries of magnesium, latent heat, specific heat, and carbon dioxide
Very Common (> 10% incidence) adverse effects Confusion Constipation (usually transient, but can persist in some) Decreased memory Diarrhea (usually transient, but can persist in some) Dry mouth ECG changes – usually benign changes in T waves Hand tremor (usually transient, but can persist in some) with an incidence of 27%. If severe, the psychiatrist may lower lithium dosage, change lithium salt type or modify lithium preparation from long to short-acting (despite lacking evidence for these procedures) or use pharmacological help Headache Hyperreflexia – overresponsive reflexes Leukocytosis – elevated white blood cell count Muscle weakness (usually transient, but can persist in some) Myoclonus – muscle twitching Nausea (usually transient) Polydipsia – increased thirst Polyuria – increased urination Renal (kidney) toxicity which may lead to chronic kidney failure, although some cases may be misattributed Vomiting (usually transient, but can persist in some) Vertigo Common (1–10%) adverse effects Acne Extrapyramidal side effects – movement-related problems such as muscle rigidity, parkinsonism, dystonia, etc. Euthyroid goitre – i.e. the formation of a goitre despite normal thyroid functioning Hypothyroidism – a deficiency of thyroid hormone. Common among bipolar patients; lithium increases rates. Hair loss/hair thinning Weight gain – 5% incidence, tends to start fast and then plateau. Usually ends at 1–2 kg. A 2022 systematic review and meta-analysis show an insignificant amount of weight gain of 0.462 kg, with higher weight gain associated with shorter use periods.
Sources: en.wikipedia.org
The curricula address subjects such as the biology of ageing, biomarkers, preventive medicine, healthspan, clinical assessment and the translation of ageing research into healthcare. The doctoral partnership with Ovidius University of Constanța began with a 2026 intake. The programme is described as a research doctorate in medicine with a specialization in longevity sciences and is not a physician qualification. Ovidius University is the degree-awarding institution. Dominik Thor serves as president of GCLS and professor of pharmacy. Luiza Spiru has held academic responsibilities within the institution, including involvement in longevity-medicine education and the Ovidius University doctoral collaboration.
=== Glucose tolerance === Middle aged (10‐month‐old) mice fed a high fat diet gained body weight and fat mass in the lower parts of their bodies and had impaired glucose tolerance as defined in glucose tolerance tests. Adding α-ketoglutarate to the drinking water of these mice inhibited the development of these changes. These results suggest that drinking the α-ketoglutarate-rich water replenished the otherwise diminished supplies of α-ketoglutarate in middle aged mice; the replenished supply of α-ketoglutarate thereby became available to suppress obesity and improve glucose tolerance. A study in rats feed a low fat or high fat diet for 27 weeks and drinking α-ketoglutarate-rich water for the last 12 weeks of this 27 week period decreased their fat issue masses and increased their whole-body insulin sensitivity as defined in glucose tolerance tests. Rats fed either of these diets but not given α-ketoglutarate-rich water did not show these changes. This study indicates that α-ketoglutarate regulates body fat mass and insulin sensitivity in rats as well as mice.
The tea leaves are packaged loosely in a canister, paper bag, or other container such as a tea chest. Some whole teas, such as rolled gunpowder tea leaves, which resist crumbling, are vacuum-packed for freshness in aluminised packaging for storage and retail. The loose tea is individually measured for use, allowing for flexibility and flavour control at the expense of convenience. Strainers, tea balls, tea presses, filtered teapots, and infusion bags prevent loose leaves from floating in the tea and over-brewing. A traditional method uses a three-piece lidded teacup called a gaiwan, the lid of which is tilted to decant the tea into a different cup for consumption.
=== Oxidative damage === In aerobic organisms the energy needed to fuel biological functions is produced in the mitochondria via the electron transport chain. Reactive oxygen species (ROS) with the potential to cause cellular damage are produced along with the release of energy. ROS can damage lipids, DNA, RNA, and proteins, which, in theory, contributes to the physiology of aging. ROS are produced as a normal product of cellular metabolism. In particular, one major contributor to oxidative damage is hydrogen peroxide (H2O2), which is converted from superoxide that leaks from the mitochondria. Catalase and superoxide dismutase ameliorate the damaging effects of hydrogen peroxide and superoxide, respectively, by converting these compounds into oxygen and hydrogen peroxide (which is later converted to water), resulting in the production of benign molecules. However, this conversion is not 100% efficient, and residual peroxides persist in the cell. While ROS are produced as a product of normal cellular functioning, excessive amounts can cause deleterious effects.
Personal cards-including ID cards and driver's licenses-are frequently swabbed by inspectors to detect drug residue, as these items are commonly used to prepare lines of cocaine. Swabbing can reveal traces of cocaine or other illicit substances, providing evidence of recent drug handling or use. This practice may be employed during security checks at border crossings. A Newsbeat investigation found that "cocaine torches" used by UK police to detect cocaine use are ineffective on typical street cocaine, as independent lab tests showed they fail to make the drug fluoresce. Experts and drug charities criticized the devices, warning they can give false positives and waste resources, while police forces defended their use as a deterrent. The manufacturer says the torches only work on much purer forms of cocaine than are found on the street. Cocaine may be detected by law enforcement using the Scott reagent. The test can easily generate false positives for common substances and must be confirmed with a laboratory test. Approximate cocaine purity can be determined using 1 mL 2% cupric sulfate pentahydrate in dilute HCl, 1 mL 2% potassium thiocyanate and 2 mL of chloroform. The shade of brown shown by the chloroform is proportional to the cocaine content. This test is not cross sensitive to heroin, methamphetamine, benzocaine, procaine and a number of other drugs but other chemicals could cause false positives.
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.