The short version of Lyophilized powder fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-04 and is reviewed periodically as new material appears.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
==== Orinoco River exploration ==== Humboldt’s expedition to the Upper Orinoco and the Casiquiare canal began at 4 a.m. on March 30, 1800, departing from San Fernando de Apure. The transition from the dry Llanos to the river marked a significant environmental change. The team, which included Don Nicolas Sotto, four Native rowers, and a pilot, traveled in a large sailing canoe outfitted with a cabin made of leaves and ox-hide benches. The river’s dense forests replaced the open horizons of the plains, and travel became more constrained. Wildlife was abundant, with numerous birds, capybaras, river dolphins, tapirs, peccaries, and alligators observed along the riverbanks, as well as piranhas and stingrays in the water. Humboldt noted the intensity of insect life, particularly at midday.
=== Role in limb regeneration === Scientists have elucidated that as well as eating up material debris, macrophages are involved in the typical limb regeneration in the salamander. They found that removing the macrophages from a salamander resulted in failure of limb regeneration and a scarring response.
The coastal taipan (Oxyuranus scutellatus) is a large, highly venomous elapid, whose range includes the southern parts of the island of New Guinea and extends in an arc along the east coast of Australia from northeastern New South Wales through Queensland and across the northern parts of the Northern Territory to northern Western Australia. This snake can be highly aggressive when cornered and will actively defend itself. They are extremely nervous and alert snakes, and any movement near them is likely to trigger an attack. When threatened, this species adopts a loose striking stance with its head and forebody raised. It inflates and compresses its body laterally (not dorso-ventrally like many other species) and may also spread the back of its jaws to give the head a broader, lance-shaped appearance. In this position the snake will strike without much provocation, inflicting multiple bites with extreme accuracy and efficiency. The muscular lightweight body of the taipan allows it to hurl itself forwards or sideways and reach high off the ground, and such is the speed of the attack that a person may be bitten several times before realizing the snake is there. This snake is considered to be one of the most venomous in the world. Ernst and Zug et al. (1996) and the Australian venom and toxin database both list an LD50 value of 0.106 mg/kg for subcutaneous injection. Engelmann and Obst (1981) list a value of 0.12 mg/kg SC, with an average venom yield of 120 mg per bite and a maximum record of 400 mg.
From the east, the East River Tunnels' lines 1 and 2 (the more southerly tubes) can only access tracks 5–17 and are used by most Amtrak and NJ Transit trains, while the East River Tunnels' lines 3 and 4 (the more northerly tubes) can only access tracks 14–21 and are mostly used by LIRR. From the west, the North River Tunnels can access tracks 1–19, while the Empire Connection can only access tracks 1–9 and the LIRR's West Side Yard can only access tracks 10–21. All station tracks are powered by 12 kV overhead wire. Tracks 5–21 also have 750 V DC third rail. Due to the lack of proper ventilation in the tunnels and station, only electric locomotives and dual-mode locomotives are scheduled to enter Penn Station. Diesel-only NJT trains terminate at Hoboken Terminal or Newark Penn Station, and diesel-only LIRR trains terminate at or prior to Long Island City. The established throughput capacity of the tunnels is 24–25 trains per hour in each direction for the North River Tunnels and 20–21 trains per hour in the peak direction for the East River Tunnels. Trains on track 18 open their doors only on the north side (platform 10).
In 1912, Frederick Gowland Hopkins demonstrated that unknown accessory factors found in milk, other than carbohydrates, proteins, and fats were necessary for growth in rats. Hopkins received a Nobel Prize for this discovery in 1929. One year later, Elmer McCollum, a biochemist at the University of Wisconsin–Madison, and colleague Marguerite Davis identified a fat-soluble nutrient in butterfat and cod liver oil. Their work confirmed that of Thomas Burr Osborne and Lafayette Mendel, at Yale, also in 1913, which suggested a fat-soluble nutrient in butterfat. The "accessory factors" were termed "fat-soluble" in 1918 and later "vitamin A" in 1920. In 1931, Swiss chemist Paul Karrer described the chemical structure of vitamin A. Retinoic acid and retinol were first synthesized in 1946 and 1947 by two Dutch chemists, David Adriaan van Dorp and Jozef Ferdinand Arens. In 1967, George Wald was a co-recipient of the Nobel Prize in Physiology and Medicine "..."for their discoveries concerning the primary physiological and chemical visual processes in the eye." Photoreceptor cells in the eye contain a chromophore composed of the protein opsin and 11-cis retinal. When struck by light, 11-cis retinal undergoes photoisomerization to all-trans retinal and via signal transduction cascade sends a nerve signal to the brain. The all-trans retinal is reduced to all-trans retinol and travels back to the retinal pigment epithelium to be recycled to 11-cis retinal and conjugated to opsin.
Sources: en.wikipedia.org
One of the most prominent campaigners was a young man from East Germany called Rudi Dutschke who also criticised the forms of capitalism that were to be seen in West Berlin. Just before Easter 1968, a young man tried to kill Dutschke as he bicycled to the student union, seriously injuring him. All over West Germany, thousands demonstrated against the Springer newspapers which were seen as the prime cause of the violence against students. Trucks carrying newspapers were set on fire and windows in office buildings broken. In the wake of these demonstrations, in which the question of America's role in Vietnam began to play a bigger role, came a desire among the students to find out more about the role of the parent-generation in the Nazi era. The proceedings of the War Crimes Tribunal at Nuremberg had been widely publicised in Germany; the attorney Fritz Bauer gathered evidence on the guards of the Auschwitz concentration camp, and about twenty were put on trial in Frankfurt in 1963. Daily newspaper reports and visits by school classes to the proceedings revealed to the German public the nature of the concentration camp system, and it became evident that the Shoah was of vastly greater dimensions than the German population had believed. The term "Holocaust" for the systematic mass-murder of Jews first came into use in 1979, when a 1978 American mini-series with that name was shown on West German television. The processes set in motion by the Auschwitz trial reverberated decades later.
The first symptoms are often mistakenly attributed to aging or stress. Detailed neuropsychological testing can reveal mild cognitive difficulties up to eight years before a person fulfills the clinical criteria for diagnosis of Alzheimer's disease. These early symptoms can affect the most complex activities of daily living. The most noticeable deficit is difficulty in remembering recently learned facts and inability to acquire new information. Subtle problems with the executive functions of attentiveness, planning, flexibility, and abstract thinking, or impairments in semantic memory (memory of meanings and concept relationships) can also be symptomatic of the early stages of Alzheimer's disease. Apathy and depression can be seen at this stage, with apathy remaining as the most persistent symptom throughout the course of the disease. People with objective signs of cognitive impairment, but not more severe symptoms, may be diagnosed with mild cognitive impairment (MCI). If memory loss is the predominant symptom of MCI, it is termed amnestic MCI and is frequently seen as a prodromal or early stage of Alzheimer's disease. Amnestic MCI has a greater than 90% likelihood of being associated with Alzheimer's.
== Epidemiology == Sydenham's chorea is primarily seen in children. As with rheumatic fever, Sydenham's chorea is seen more often in less affluent communities, whether in the developing world or in aboriginal communities in the global North. High rates of impetigo are a marker for widespread streptococcal transmission. In the UK, there are approximately 20 cases per year, according to a BPSU surveillance study.
== Match-fixing scandals == Ten of the twelve members of the gold medal-winning Spanish basketball team at the 2000 Summer Paralympics were revealed to have no disability. Fresno Case scandal (2004) – an attempt to rig a vote to prevent the Catalan rink hockey team from being accepted into international competition. Melbourne Football Club tanking scandal (2009) – allegations arose that the club deliberately lost matches in 2009 so that it would put itself into a position whereby they would secure a priority draft pick at that year's draft. In 2011, snooker player John Higgins was accused of accepting bribery in order to lose frames purposefully. Higgins denied any accusations of match-fixing and bribery, however, he was found guilty of accepting bribery while there was no evidence for him match-fixing. "World number one John Higgins has been suspended from all future tournaments after reportedly agreeing to take a £261,000 bribe to lose frames." Match fixing in tennis 1964 British football match-fixing scandal 1971 Bundesliga scandal Match-fixing investigations of Norwegian Second Division Match fixing in English football Match fixing in Romanian football
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.