If you have been reading about methionine sulfoxide 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 2026-01-29. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
The process of pasteurizing donkey milk deactivates bacterial and viral contaminants. Donkey milk contains immune-enhancing compounds (in particular lysozyme and lactoferrin) to help protect infants from disease. In addition, the flavour and appearance of donkey milk are attractive to children.
The adaptor hypothesis was framed to explain how information could be extracted from a nucleic acid and used to put together a string of amino acids in a specific sequence, that sequence being determined by the nucleotide sequence of the nucleic acid (DNA or RNA) template. Crick proposed that each amino acid is first attached to its own specific "adaptor" piece of nucleic acid (in an enzyme-catalysed reaction). The order of assembly of the amino acids is then determined by a specific recognition between the adaptor and the nucleic acid which is serving as the informational template. In this way the amino acids could be lined up by the template in a specific order. Coupling between adjacent amino acids would then lead to the synthesis of a polypeptide whose sequence is determined by the template nucleic acid.
According to this narrative, South African paratroopers opened fire on the refugees, mostly women and children; those not immediately killed were systematically rounded up into groups and bayoneted or shot. The alleged result was the massacre of at least 612 South West African civilians, almost all elderly men, women, and children. The SADF narrative concurred with a death toll of approximately 600 but claimed that most of the dead were insurgents killed defending a series of trenches around the camp. South African sources identified Cassinga as a PLAN installation on the basis of aerial reconnaissance photographs, which depicted a network of trenches as well as a military parade ground. Additionally, photographs of the parade ground taken by a Swedish reporter just prior to the raid depicted children and women in civilian clothing, but also uniformed PLAN guerrillas and large numbers of young men of military age. SWAPO maintained that it ordered the trenches around Cassinga dug to shelter the otherwise defenceless refugees in the event of a SADF raid, and only after camp staff had noted spotter planes overhead several weeks prior. It justified the construction of a parade ground as part of a programme to instill a sense of discipline and unity. Western journalists and Angolan officials counted 582 corpses on site a few hours after the SADF's departure. The SADF suffered 3 dead and 1 missing in action.
Sources: en.wikipedia.org
=== Genetics === The observation of high rates of autoimmune disorders in families with a history of Sjögren's disease is linked with a genetic predisposition to the disease. Studies on the polymorphisms of human leukocyte antigen (HLA)-DR and HLA-DQ gene regions in Sjögren's patients show differential susceptibility to the disease as the result of different types of the resulting autoantibody production.
The sudden cardiac death of athletes is typically defined as natural, unexpected death from cardiac arrest within one hour of the onset of collapse symptoms, excluding additional time on mechanical life support. (Wider definitions of sudden death are also in use, but not usually applied to the athletic situation.) Most causes relate to congenital or acquired cardiovascular disease with no symptoms noted before the fatal event. The prevalence of any single, associated condition is low, with the most common affecting nearly 0.5% of the general population, and the sensitivity and specificity of common screening tests leave much to be desired. The single most important predictor is fainting or near-fainting during exercise, which should require detailed explanation and investigation. The victims include many well-known names, especially in professional association football, and close relatives are often at risk for similar cardiac problems.
Conventional radiotherapy, limited to the involved area of tumour, is the mainstay of treatment for DIPG. The standard treatment is a total radiation dosage ranging from 5400 to 6000 cGy, administered in daily fractions of 180 to 200 cGy (5 days/week over 6 weeks). Hyperfractionated (twice-daily) radiotherapy was used previously to deliver higher radiation dosages, but did not lead to improved survival in clinical trials. Hyperfractionated radiotherapy is no longer commonly used due to lack of clinical support showing improved survival rates, the discomfort of two radiotherapy sessions a day, and an increased risk in damaging healthy organs due to higher dosages. Radiosurgery (e.g., gamma knife or cyberknife) has a role in the treatment of DIPG and may be considered in selected cases.
=== Direct acid-set method === The direct acid-set method bypasses bacterial fermentation. Instead, food-grade acids (such as vinegar, citric acid, or lactic acid) are added directly to cold skimmed milk to induce instant coagulation. This method is common in high-volume manufacturing in Canada and the United States. Eliminating the fermentation window reduces overall production timelines by approximately half and prevents "vat failures" caused by bacteriophages (viruses that disrupt starter cultures). Because the process does not produce natural fermentation aromatics, a starter distillate (diacetyl) is often added to impart a buttery flavour profile similar to cultured varieties. Under US regulations, cottage cheese manufactured via this process must be labelled as "direct acid set".
Sources: en.wikipedia.org
Hydrolysis of proteins with broad specificity, cleaving Phe24-Phe and Tyr26–Thr but not Leu15-Tyr and Phe25-Tyr in the B chain of insulin. It also cleaves the His6–Pro bond of angiotensin I, the ability to cleave a peptide bond with Pro in the P1′ position is unusual. This endopeptidase is isolated from Scytalidium lignicolum. It is an acid protease, and is most active at pH 2.0 when casein is used as substrate. Eqolosins prefer bulky amino acid residues at the P1 site and small amino acid residues at the P1′ site. The substrate specificity of scytalidoglutamic peptidase is unique, particularly in the substrate preferences at the P3 (basic amino acid), P1′ (small amino acid) and P3′ (basic) positions.
In New Hampshire, many summits rise above 5,000 ft (1,500 m), including Mount Washington in the White Mountains at 6,288 ft (1,917 m), Adams at 5,771 ft (1,759 m), Jefferson at 5,712 ft (1,741 m), Monroe at 5,380 ft (1,640 m), Madison at 5,367 ft (1,636 m), Lafayette at 5,249 feet (1,600 m), and Lincoln at 5,089 ft (1,551 m). In the Green Mountains the highest point, Mt. Mansfield, is 4,393 ft (1,339 m) in elevation; others include Killington Peak at 4,226 ft (1,288 m), Camel's Hump at 4,083 ft (1,244 m), Mt. Abraham at 4,006 ft (1,221 m), and a number of other heights exceeding 3,000 ft (900 m).
Instant miso soup is available in single-serving packets. It is usually sold in dehydrated powder and paste forms, and sometimes freeze dried. It generally contains dried toppings such as wakame and tofu with soybeans that reconstitute rapidly on the addition of hot water. These are popular in the Japanese workplace, where miso soup can be made with lunch as easily as tea. Instant miso soup is available in many grocery stores outside Japan and has a shelf life of 3 to 12 months.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.