Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-05. 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. 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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Reaction of copernicium atoms with trigonal selenium to form a selenide was observed, with -ΔHadsCn(t-Se) > 48 kJ/mol, with the kinetic hindrance towards selenide formation being lower for copernicium than for mercury. This was unexpected as the stability of the group 12 selenides tends to decrease down the group from ZnSe to HgSe.
=== Thrombolysis, stenting and surgery === Thrombolysis, stenting and surgery are not used as widely as anticoagulation or antiplatelet drugs. These treatments are invasive, and are typically reserved for situations where symptoms worsen despite medical treatment, or where medical treatment may be unsafe (e.g. an unacceptable bleeding tendency). Thrombolysis is enzymatic destruction of blood clots. This is achieved by the administration of a drug (such as urokinase or alteplase) that activates plasmin, an enzyme that occurs naturally in the body and digests clots when activated. Thrombolysis is an accepted treatment for heart attacks and stroke unrelated to dissection. In cervical artery dissection, only small case series are available. The thrombolytic drug is administered either intravenously or during cerebral angiography through a catheter directly into the affected artery. The data indicates that thrombolysis is safe, but its place in the treatment of VAD is uncertain. Stenting involves the catheterization of the affected artery during angiography, and the insertion of a mesh-like tube; this is known as "endovascular therapy" (inside the blood vessel). This may be performed to allow the blood to flow through a severely narrowed vessel, or to seal off an aneurysm. However, it is unclear whether the technical success of the procedure translates into improved outcomes, as in both cases the problem often resolves spontaneously over time.
Paradoxical effects: In some cases, paradoxical effects can occur with benzodiazepines, such as increased hostility, aggression, angry outbursts, and psychomotor agitation. These effects are seen more commonly with lorazepam than with other benzodiazepines. Paradoxical effects are more likely to occur with higher doses, in people with pre-existing personality disorders and those with a psychiatric illness. Frustrating stimuli may trigger such reactions, though the drug may have been prescribed to help the person cope with such stress and frustration in the first place. As paradoxical effects appear to be dose-related, they usually subside on dose reduction or on complete withdrawal of lorazepam. Suicidality: Benzodiazepines are associated with an increased risk of suicide, possibly due to disinhibition. Higher dosages appear to confer greater risk. Amnesic effects: Among benzodiazepines, lorazepam has relatively strong amnesic effects, but people soon develop tolerance to this with regular use. An initial total daily lorazepam dose that does not exceed 2 mg may help avoid amnesia (or excess sedation) being a problem. This also applies to use for night sedation. Five participants in a sleep study were prescribed lorazepam 4 mg at night, and the next evening, three subjects unexpectedly volunteered memory gaps for parts of that day, an effect that subsided completely after two to three days' use. Amnesic effects cannot be estimated from the degree of sedation present, since the two effects are unrelated.
=== Cuban Thaw and attempts to repair relationship === In 2011, Lazaro Cuesta Valdes was elected as the Grand Commander of the Supreme Council of Cuba. After his election, the Supreme Council created a Facebook page, launched an updated webpage, and launched the first International Conference on Freemasonry and Integration to Current Society. Between 2012 and 2014, Grand Commander Cuesta Valdes travelled around the world, first to Rome, and then to visit the Supreme Councils of the United States' Southern Jurisdiction and Northern Jurisdiction, in Ohio and Washington, D.C. Informally, he also met with leaders of the Cuban exile Freemasonry community in Miami to strengthen relations with the United States. In October 2013, the Supreme Council of Cuba held an open meeting and invited Cuban Masons living anywhere to Havana to discuss the fractured state of Cuban Freemasonry. Grand Master Gutierrez Torres attended and drafted Official Message No. 6 after discussions with members of the diaspora. In April 2014, while still in prison, Alan Gross launched a hunger strike to protest his treatment by both Cuba and the United States. When the Associated Press leaked the ZunZuneo program documents to the public, Senator Patrick Leahy called it: "Dumb, dumb, dumb." Leahy then led the Senate committee review of the debacle. On December 17, 2014, Alan Gross was released from Cuban prison in exchange for three members of the Cuban Five, who had been detained in the United States and charged with espionage. On December 10, 2016, the Lazaro F.
Sources: en.wikipedia.org
Risk factors for opioid overdose include opioid dependence, injecting opioids, using high doses of opioids, and use together with alcohol, benzodiazepines, or cocaine. The risk is particularly high following detoxification. Dependence on prescription opioids can occur from their use to treat chronic pain. In young children, an overdose is usually due to opioids that are intended for their parents, older siblings, or grandparents. In mothers who take codeine during breastfeeding, opioid overdoses have occurred in their baby. Codeine is, therefore, not recommended for those who are breastfeeding.
Freezing is also one of the most commonly used processes, both commercially and domestically, for preserving a very wide range of foods, including prepared foods that would not have required freezing in their unprepared state. For example, potato waffles are stored in the freezer, but potatoes themselves require only a cool dark place to ensure many months' storage. Cold stores provide large-volume, long-term storage for strategic food stocks held in case of national emergency in many countries.
The other route uses glutathione (GSH) to conjugate with arsenic (III) to form an arsenic (GS) 3 complex. This complex can form a monomethylated arsenic (III) GS complex, using Cyt19 arsenic methyltransferase, and this monomethylated GS complex is in equilibrium with the monomethylated arsenic (III). Cyt19 arsenic methyltransferase can methylate the complex one more time, and this forms a dimethylated arsenic GS complex, which is in equilibrium with a dimethyl arsenic (III) complex. Both of the mono-methylated and di-methylated arsenic compounds can readily be excreted in urine. However, the monomethylated compound was shown to be more reactive and more toxic than the inorganic arsenic compounds to human hepatocytes (liver), keratinocytes in the skin, and bronchial epithelial cells (lungs). Studies in experimental animals and humans show that both inorganic arsenic and methylated metabolites cross the placenta to the fetus, however, there is evidence that methylation is increased during pregnancy and that it could be highly protective for the developing organism. Enzymatic methylation of arsenic is a detoxification process; it can be methylated to methylarsenite, dimethylarsenite or trimethylarsenite, all of which are trivalent. The methylation is catalyzed by arsenic methyltransferase (AS3MT) in mammals, which transfers a methyl group on the cofactor S-adenomethionine (SAM) to arsenic (III). An orthologue of AS3MT is found in bacteria and is called CmArsM. This enzyme was tested in three states (ligand free, arsenic (III) bound and SAM bound).
Algae are prominent in bodies of water, common in terrestrial environments, and are found in unusual environments, such as on snow and ice. Seaweeds grow mostly in shallow marine waters, less than 100 m (330 ft) deep; however, some such as Navicula pennata have been recorded to a depth of 360 m (1,180 ft). A type of algae, Ancylonema nordenskioeldii, was found in Greenland in areas known as the 'Dark Zone', which caused an increase in the rate of melting ice sheet. The same algae was found in the Italian Alps, after pink ice appeared on parts of the Presena glacier. The various sorts of algae play significant roles in aquatic ecology. Microscopic forms that live suspended in the water column (phytoplankton) provide the food base for most marine food chains. In very high densities (algal blooms), these algae may discolor the water and outcompete, poison, or asphyxiate other life forms.
Lipotropin is the name for two hormones produced by the cleavage of pro-opiomelanocortin (POMC). The anterior pituitary gland produces the pro-hormone POMC, which is then cleaved again to form adrenocorticotropin (ACTH) and β-lipotropin (β-LPH).
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.