nootropic is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-10-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
=== Support for retail reforms === In a pan-Indian survey conducted over the weekend of 3 December 2011, overwhelming majority of consumers and farmers in and around ten major cities across the country support the retail reforms. Over 90 per cent of consumers said FDI in retail will bring down prices and offer a wider choice of goods. Nearly 78 per cent of farmers said they will get better prices for their produce from multi-format stores. Over 75 per cent of the traders claimed their marketing resources will continue to be needed to push sales through multiple channels, but they may have to accept lower margins for greater volumes. A study in India on title 'Foreign Direct Investment In Indian Retail Sector: Drawing lessons from the international experience', concluded that the entry of FDI in multi brand retail in India can be growth enhancing only if proper safeguards are in place and the market environment is regulated. Firstly, the resources should be dedicated for a comprehensive study of retail and its related industries. Secondly, the number of big retail outlets in a particular city should be decided on the basis of population criterion and the employment level of local youth in the retail business. Thirdly, the format of these retail chains should also be regulated as is done in Malaysian case. They should not be in the form of neighborhood convenience store and there should be minimum and maximum limit of the size of these stores.
Belize was granted independence on 21 September 1981. Guatemala refused to recognize the new nation because of its longstanding territorial dispute, claiming that Belize belonged to Guatemala. After independence about 1,500 British troops remained in Belize to deter any possible Guatemalan incursions. With George Cadle Price at the helm, the PUP won all national elections until 1984. In that election, the first national election after independence, the PUP was defeated by the United Democratic Party (UDP). UDP leader Manuel Esquivel replaced Price as prime minister, with Price himself unexpectedly losing his own House seat to a UDP challenger. The PUP under Price returned to power after elections in 1989. The following year the United Kingdom announced that it would end its military involvement in Belize, and the RAF Harrier detachment was withdrawn the same year, having remained stationed in the country continuously since its deployment had become permanent there in 1980. British soldiers were withdrawn in 1994, but the United Kingdom left behind a military training unit to assist with the newly created Belize Defence Force. The UDP regained power in the 1993 national election, and Esquivel became prime minister for a second time. Soon afterwards, Esquivel announced the suspension of a pact reached with Guatemala during Price's tenure, claiming Price had made too many concessions to gain Guatemalan recognition. The pact may have curtailed the 130-year-old border dispute between the two countries.
==== Inflammation and allergy ==== 12-HHT stimulates chemotactic responses in mouse bone marrow mast cells, which naturally express BLT2 receptors, as well as in Chinese hamster ovary cells made to express these receptors by transfection. These findings suggest that the 12-HHT/BLT2 receptor pathway may support the pro-inflammatory (i.e. chemotactic) actions of the LTB4/BLT1 pathway. On the other hand, the immortalized human skin cell line HaCaT expresses BLT2 receptors and responds to ultraviolet B (UVB) radiation by generating toxic reactive oxygen species which in turn cause the HaCaT cells to die by activating apoptotic pathways in a BLT2 receptor-dependent reaction. Topical treatment of mouse skin with a BLT2 receptor antagonist, LY255283, protects against UVB radiation-induced apoptosis and BLT2-overexpressing transgenic mice exhibited significantly more extensive skin apoptosis in response to UVB irradiation. Furthermore, 12-HHT inhibits HaCaT cells from synthesizing interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation, in response to UVB radiation. These results suggest that the 12-HHT/BLT2 axis can act to suppress inflammation by promoting the orderly death of damaged cells and blocking IL-6 production. Opposition between the pro-inflammatory LTB4/BLT1 and anti-inflammatory actions of the 12-HHT/BLT2 axes occurs in another setting.
=== Aquacobalamin reductase (NADPH) activity === Belongs to the oxidoreductase family, oxidizing metal ions with NADP+ acting as an electron acceptor. Uses FAD as a cofactor when catalyzing the following reaction: 2cob(II)alamin + NADP+ 2aquacob(III)alamin + NADPH + H+.
Sources: en.wikipedia.org
Shortly before his retirement in 1983, he submitted data requested by the FDA, which had begun to regulate medical devices following a 1977 meeting on the topic, regarding DBS for chronic pain. Medtronic and Neuromed also made deep brain stimulators at the time, but reportedly felt a complex safety and efficacy clinical trial in patients who were difficult to evaluate would be too costly for the size of the potential patient base, so did not submit clinical data on DBS for chronic pain to the FDA, and that indication was de-approved. However, near this time in France and elsewhere, DBS was investigated as a substitute for lesioning of brain nuclei to control motor symptoms of movement disorders such as Parkinson's disease, and by the mid-1990s, this reversible, non-destructive stimulation therapy had become the primary application of DBS in appropriate patients, to slow progression of movement impairment from the disease and reduce side effects from long-term, escalating medication use.
Hitler's aspirations to hegemony over Europe and the establishment of the New Order, already evident from architectural and decorative features of the new Chancellery, are even more clearly expressed here. External symbols suggest that the domed hall was where Hitler as cosmocrat (Herr der Welt) would appear before his Herrenvolk: On top of the dome's lantern was the German heraldic eagle clutching the globe of the Earth (Erdball). This symbolism was well known in imperial Roman iconography, for example, the restored statue of Claudius holding a ball and eagle in his right hand. The vast dome, on which it rested, as with Hadrian's Pantheon, symbolically represented the vault of the sky spanning Germany's empire. The globe on the dome's lantern was enhanced and emphasised by two monumental sculptures by Breker, each 15 metres tall, which flanked the north façade of the building: at its west end Atlas supporting the heavens, at its east end Tellus supporting the Earth. Both mythological figures were chosen by Hitler himself. Giesler says that Speer was wrong to represent the Volkshalle as a symbol of World Domination (Weltherrschaft). Speer in his 1971 Playboy magazine interview states:
=== Origin of selenoproteins === From about three billion years ago, prokaryotes evolved selenoprotein families centering around the selenocysteine machinery. Several selenoprotein families are known in bacteria, archaea, and eukaryotes, invariably owing to the presence of selenocysteine. They protect their host cells from oxidative damage. Selenium enzymes are involved in utilization of the small reducing molecules glutathione and thioredoxin, common intracellular antioxidants and redox partners. Selenoprotein families of GSH-Px and the deiodinases of eukaryotic cells seem to have a bacterial phylogenetic origin. The selenocysteine-containing form occurs in species as diverse as green algae, diatoms, sea urchins, fish, and chickens.
== Further reading == Alberts, B. et al. (2002). Molecular Biology of the Cell, 4th ed. New York: Garland Science. ISBN 0-8153-3218-1. Berg, J. M. et al. (2002). Biochemistry, 5th ed. New York: W.H. Freeman and Company. ISBN 0-7167-3051-0. Singh, B. D. (2002). Fundamentals of Genetics, New Delhi, India: Kalyani Publishers. ISBN 81-7663-109-4.
American black bears were once not considered true or "deep" hibernators, but because of discoveries about the metabolic changes that allow black bears to remain dormant for months without eating, drinking, urinating or defecating, most biologists have redefined mammalian hibernation as "specialized, seasonal reduction in metabolism concurrent with scarce food and cold weather". American black bears are now considered highly efficient hibernators. The physiology of American black bears in the wild is closely related to that of bears in captivity. Understanding the physiology of bears in the wild is vital to the bear's success in captivity. The bears enter their dens in October and November, although in the southernmost areas of their range (i.e. Florida, Mexico, the southeastern United States), only pregnant females and mothers with yearling cubs will enter hibernation. Prior to that time, they can put on up to 14 kg (30 lb) of body fat to get them through the several months during which they fast. Hibernation typically lasts 3–8 months, depending on regional climate. Hibernating bears spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts, and in shallow depressions. Although naturally-made dens are occasionally used, most dens are dug out by the bear. During their time in hibernation, an American black bear's heart rate drops from 40 to 50 beats per minute to 8 beats per minute, and the metabolic rate can drop to a quarter of the bear's (non-hibernating) basal metabolic rate.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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.