Everything below concerns RP-HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
=== Efficacy === In people with either type of dementia, rivastigmine has been shown to provide meaningful symptomatic effects that may allow patients to remain independent and 'be themselves' for longer. In particular, it appears to show marked treatment effects in patients showing a more aggressive course of disease, such as those with younger onset ages, poor nutritional status, or those experiencing symptoms such as delusions or hallucinations. For example, the presence of hallucinations appears to be a predictor of especially strong responses to rivastigmine, both in Alzheimer's and Parkinson's patients. These effects might reflect the additional inhibition of butyrylcholinesterase, which is implicated in symptom progression and might provide added benefits over acetylcholinesterase-selective drugs in some patients. Multiple-infarct dementia patients may show slight improvement in executive functions and behaviour. No firm evidence supports usage in schizophrenia patients. Its efficacy is similar to donepezil and tacrine. Doses below 6 mg/d may be ineffective. The effects of this kind of drug in different kinds of dementia (including Alzheimer's dementia) are modest, and it is still unclear which AChE (BChE) esterase inhibitor is better in Parkinson's dementia, though rivastigmine is well-studied.
Many of these forms are initially water-soluble, which is a disadvantage where the material must retain its shape within the body. Stability is achieved by increasing the beta-sheet content, through treatment with methanol or ethanol, exposure to water vapour, mechanical stretching, or controlled heating. Because the same ordered structure governs both strength and the rate of degradation, this step also serves as the principal means of tuning a material's properties.
== Quinine content == Medicinal tonic water originally contained only carbonated water and a large amount of quinine. Most modern tonic waters contain comparatively less quinine, and are often enhanced by citrus flavours. As a result of the lower quinine content, tonic water is less bitter. It is also usually sweetened, often with the addition of high-fructose corn syrup or sugar. Some manufacturers also produce diet (or "slimline") tonic water, which may contain sugar substitutes such as aspartame. Traditional-style tonic water with high amounts of quinine and carbonated water is less common, but may be preferred by those who desire the bitter flavour. In the United States, the US Food and Drug Administration (FDA) limits the quinine content in tonic water to 83 ppm (83 mg per litre). In Europe, the limit is 100 mg/L, which is 0.25–0.50% of the original strength. The therapeutic dose of quinine is 10 mg per kg of body mass every eight hours for effective malaria prevention (2,100 mg daily for a 70-kilogram (150 lb) adult). Until about 2010, quinine was often recommended as a relief for leg cramps, although medical research suggested some care was needed in monitoring doses. Because of quinine's risks, the FDA cautions consumers against using "off-label" quinine drugs to treat leg cramps.
Sources: en.wikipedia.org
Around 8,000 Canadians arrived in South Africa to fight for Britain. These arrived in contingents: the first on 30 October 1899, the second on 21 January 1900. A third contingent of cavalry (Strathcona's Horse) embarked on 16/17 March 1900. They remained until May 1902. With approximately 7,368 soldiers in a combat zone, the conflict became the largest engagement involving Canadian soldiers from the time of Confederation until the Great War. 270 of them died during the war. The arrival and movement of troops was widely documented by war photographers. English-born, and later Canadian, Inglis Sheldon-Williams was one of the most notable, documenting movement of hundreds of troops to Africa. The Canadian public was initially divided on the decision to go to war, as some did not want Canada to become Britain's 'tool' for engaging in armed conflicts. Many Anglophone citizens were pro-Empire, and wanted prime minister Sir Wilfrid Laurier to support the British. Many Francophone citizens felt threatened by the continuation of British imperialism to their national sovereignty. In the end, to appease citizens who wanted war and avoid angering those against it, Laurier sent 1,000 volunteers under the command of Lieutenant Colonel William Otter to aid the confederation in its war to 'liberate' the peoples of the Boer controlled states in South Africa. The volunteers were provided to the British if the latter paid costs of the battalion after it arrived in South Africa.
Immunization, vaccine preventable diseases and polio transition World Health Organization WHO Vaccine Position Papers World Health Organization The History of Vaccines, from the College of Physicians of Philadelphia This website was highlighted by Genetic Engineering & Biotechnology News in its "Best of the Web" section in January 2015. See: "The History of Vaccines". Best of the Web. Genetic Engineering & Biotechnology News. Vol. 35, no. 2. 15 January 2015. p. 38.
==== United States Food and Drug Administration ==== In the United States of America, which was otherwise unaffected by the scares, the US distributor of White Rabbit candies recalled the product when samples found in Hartford showed traces of melamine. The candy's maker and subsidiary of Bright Foods, Guan Sheng Yuan, issued a recall to the 50 countries to which it exported. The U.S. Food and Drug Administration said while food containing melamine below 2.5 parts per million generally did not raise concerns, its scientists were "currently unable to establish any level of melamine and melamine-related compounds in infant formula that does not raise public health concerns". On 12 November 2008, the FDA issued a general alert against all finished food products from China, saying that information received from government sources in a number of countries indicates a wide range and variety of products from a variety of producers have been manufactured using melamine-contaminated milk was a recurring problem. In late November, after the FDA found traces of melamine in one Nestle and one Mead Johnson infant product, the FDA concluded melamine or cyanuric acid alone, "at or below 1 part per million in infant formula do not raise public health concerns" in babies. The United States Food and Drug Administration opened its first overseas inspection offices in November 2008, with bureaus in Shanghai, Beijing and Guangzhou.
== Catabolism and excretion == Steroids are primarily oxidized by cytochrome P450 oxidase enzymes, such as CYP3A4. These reactions introduce oxygen into the steroid ring, allowing the cholesterol to be broken up by other enzymes into bile acids. These acids can then be eliminated by secretion from the liver in bile. The expression of the oxidase gene can be upregulated by the steroid sensor PXR when there is a high blood concentration of steroids. Steroid hormones, lacking the side chain of cholesterol and bile acids, are typically hydroxylated at various ring positions or oxidized at the 17 position, conjugated with sulfate or glucuronic acid and excreted in the urine.
Sources: en.wikipedia.org
==== Stations ==== A Police Station is the basic unit of policing, responsible for prevention and detection of crime, maintenance of public order, enforcing law in general as well as for performing protection duties and making security arrangements for the constitutional authorities, government functionaries, representatives of the public in different legislative bodies and local self governments, public figures etc. A Police Station is headed by either a Sub-Inspector (lower subordinate rank), mostly in rural areas or an Inspector (an upper subordinate rank), mostly in urban areas. Police outposts are headed by a Sub-Inspector or Assistant Sub Inspector. After the year 2009 both ASI and SI have equal investigation power and both serve as duty officers.
The bonnet is usually a copper shell with soldered brass fittings. It covers the diver's head and provides sufficient space to turn the head to look out of the glazed faceplate and other viewports (windows). The front port can usually be opened for ventilation and communication when the diver is on deck, by being screwed out or swung to the side on a hinge. The other lights (another name for the viewports) are generally fixed. Viewports were glass on the early helmets, with some of the later helmets using acrylic, and are usually protected by brass or bronze grilles. The helmet has fittings to connect the air line and the diver's telephone. All except the earliest helmets include a non-return valve where the airline is connected, which prevents potentially fatal helmet squeeze if the pressure in the hose is lost. The difference in pressure between the surface and the diver can be so great that if the air line is cut at or near the surface and there is no non-return valve, the diver would be partly squeezed into the helmet by the external pressure, and injured or possibly killed. Helmets also have a spring-loaded exhaust valve which allows excess air to leave the helmet. The spring force is adjustable by the diver to prevent the suit from deflating completely or over-inflating and the diver being floated uncontrollably to the surface. Some helmets have an extra manual valve known as a spit-cock, which can be used to vent excess air when the diver is in a position where the main exhaust can not function correctly.
Many ectomycorrhizal fungi rely upon mammals for the dispersal of their spores, particularly fungi with hypogeous fruiting bodies. Many species of small mammals are mycophages, eating a wide range of fungi and especially the fruiting bodies. Spores are dispersed either because the fruiting body is unearthed and broken apart, or after ingestion and subsequent excretion. Some studies even suggest that passage through an animal's gut promotes spore germination, although for most fungal species this is not necessary. By spreading the fungal spores, these animals have an indirect effect on plant community structure. Other fruiting bodies are eaten by invertebrates such as mollusks and fly larvae, some of which are even tolerant to the toxic α-amanitin found in death caps. Below ground, nematodes and springtails also consume fungal tissue. The ectomycorrhizal fungus Laccaria bicolor has been found to lure and kill springtails to obtain nitrogen, some of which may then be transferred to the host plant. In one study, eastern white pine inoculated with L. bicolor was able to derive up to 25% of its nitrogen from springtails. Edible fungi are important in societies throughout the world. Truffles, porcinis and chanterelles are known for their culinary and financial importance.
This list of nuclides shows observed nuclides that either are stable or, if radioactive, have half-lives longer than one hour. This includes isotopes of the first 105 elements, except for 87 (francium), 102 (nobelium) and 104 (rutherfordium). More than 5,000 nuclides have been experimentally characterized, including isomers, of which this page presently includes 987.
== Side effects == The main side effects of relugolix for uterine fibroids include abnormal uterine bleeding (24.6–48.6% vs. 6.3% for placebo), hot flashes (42.8–45.5% vs. 0% for placebo), heavy menstrual bleeding (12.1–49.3% vs. 9.4% for placebo), headache (12.3–15.2%), and excessive sweating (9.4–15.2% vs. 0% for placebo). In addition, decreased bone mineral density occurs with relugolix (21.7% decrease by week 12, 24.4% decrease by week 24).
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.