Melanocortin receptor 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.
Updated 2025-09-05. Numbers and descriptions here follow the published literature rather than marketing material.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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 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.
Gilgo Beach serial killings: Rex Heuermann pleas guilty to killing eight women between 1993 and 2010 on Long Island. Jasveen Sangha is sentenced to 15 years in federal prison for distributing ketamine that resulted in the death of Friends actor Matthew Perry in 2023. April 9 The DNC votes against a resolution to limit AIPAC influence. Melania Trump delivers a rare public statement at the White House denying any connection to Jeffrey Epstein and his associate Ghislaine Maxwell. She calls allegations linking her to Epstein "lies" and urges Congress to hold public hearings for survivors of Epstein's sex trafficking. The FBI launches an antitrust investigation into the NFL. April 10 Iran war: U.S. inflation rises to 3.3% year-on-year in March, a two-year high, driven by higher energy and goods prices linked to disruptions caused by the Iran war. Artemis II successfully returns to Earth, splashing down safely in the Pacific Ocean near San Diego. The four crew members are extracted from the capsule and taken by helicopter to the USS John P Murtha. April 11 Iran and the United States hold ceasefire talks in Islamabad, Pakistan, making it the first highest-level engagement between the two countries since the Iranian Revolution in 1979. The U.S. delegation is led by Vance. The U.S. Central Command has confirmed that the U.S. Navy Arleigh Burke-class destroyers USS Frank Peterson and USS Michael Murphy have crossed the Strait of Hormuz to ensure the strait is clear of sea mines.
=== Medical use === Cryosurgery procedures such as cryoablation use liquid argon to destroy tissue such as cancer cells. It is used in a procedure called "argon-enhanced coagulation", a form of argon plasma beam electrosurgery. The procedure carries a risk of producing gas embolism and has resulted in the death of at least one patient. Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects. Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox, to speed the elimination of dissolved nitrogen from the blood.
=== Mechanism of action === The molecular mechanism of metformin is not completely understood. Multiple potential mechanisms of action have been proposed: inhibition of the mitochondrial respiratory chain (complex I), activation of AMP-activated protein kinase (AMPK), inhibition of glucagon-induced elevation of cyclic adenosine monophosphate (cAMP) with reduced activation of protein kinase A (PKA), complex IV–mediated inhibition of the GPD2 variant of mitochondrial glycerol-3-phosphate dehydrogenase (thereby reducing the contribution of glycerol to hepatic gluconeogenesis), and an effect on gut microbiota. Metformin exerts an anorexiant effect in most people, decreasing caloric intake. Metformin decreases gluconeogenesis (glucose production) in the liver. Metformin inhibits basal secretion from the pituitary gland of growth hormone, adrenocorticotropic hormone, follicle stimulating hormone, and expression of proopiomelanocortin, which in part accounts for its insulin-sensitizing effect with multiple actions on tissues including the liver, skeletal muscle, endothelium, adipose tissue, and the ovaries. The average person with type 2 diabetes has three times the normal rate of gluconeogenesis; metformin treatment reduces this by over one-third. Activation of AMPK was required for metformin's inhibitory effect on liver glucose production. AMPK is an enzyme that plays an important role in insulin signaling, whole-body energy balance, and the metabolism of glucose and fats.
It is unlikely that a person would overdose on nicotine through smoking alone. The US Food and Drug Administration (FDA) stated in 2013 that there are no significant safety concerns associated with the use of more than one form of over-the-counter (OTC) nicotine replacement therapy at the same time, or using OTC NRT at the same time as another nicotine-containing product, like cigarettes. The median lethal dose of nicotine in humans is unknown. Nevertheless, nicotine has a relatively high toxicity in comparison to many other alkaloids such as caffeine, which has an LD50 of 127 mg/kg when administered to mice. At sufficiently high doses, it is associated with nicotine poisoning, which, while common in children (in whom poisonous and lethal levels occur at lower doses per kilogram of body weight) rarely results in significant morbidity or death. The estimated lower dose limit for fatal outcomes is 500–1,000 mg of ingested nicotine for an adult (6.5–13 mg/kg). The initial symptoms of a nicotine overdose typically include nausea, vomiting, diarrhea, hypersalivation, abdominal pain, tachycardia (rapid heart rate), hypertension (high blood pressure), tachypnea (rapid breathing), headache, dizziness, pallor (pale skin), auditory or visual disturbances, and perspiration, followed shortly after by marked bradycardia (slow heart rate), bradypnea (slow breathing), and hypotension (low blood pressure). An increased respiratory rate (i.e., tachypnea) is one of the primary signs of nicotine poisoning.
== Pharmacokinetic properties == Imipenem/cilastatin/relabactam is an hydrophilic compound. The distribution of imipenem/relebactam is prevalent in the interstitial spaces. Protein binding is 20% for imipenem, 20% for cilastatin and 22% for relebactam; volume of distribution is 24.3 L for imipenem and cilastatin and 19 L for relebactam. The two drugs achieve relatively high concentrations in the respiratory system: the exposure in epithelial lining fluid, relative to that of unbound concentrations in plasma, is 55% for imipenem and 54% for relebactam. Both imipenem and relebactam have renal clearance and a half-life of approximately 1 h. Dose adjustment should be performed in renal impairment.
Sources: en.wikipedia.org
Life consists of reproduction with (heritable) variations. NASA defines life as "a self-sustaining chemical system capable of Darwinian evolution." Such a system is complex; the last universal common ancestor (LUCA), presumably a single-celled organism which lived some 4 billion years ago, already had hundreds of genes encoded in the DNA genetic code that is universal today. That in turn implies a suite of cellular machinery including messenger RNA, transfer RNA, and ribosomes to translate the code into proteins. Those proteins included enzymes to operate its anaerobic respiration via the Wood–Ljungdahl metabolic pathway, and a DNA polymerase to replicate its genetic material. The challenge for origin of life researchers is to explain how such a complex and tightly interlinked system could develop by evolutionary steps, as at first sight all its parts are necessary to enable it to function. For example, a cell, whether the LUCA or in a modern organism, copies its DNA with the DNA polymerase enzyme, which is itself produced by translating the DNA polymerase gene in the DNA. Neither the enzyme nor the DNA can be produced without the other. The evolutionary process could have started with molecular self-replication, self-assembly such as of cell membranes, and autocatalysis via RNA ribozymes in an RNA world environment. The transition of non-life to life has not been observed experimentally. Some scientists see both life and the origin of life as aspects of the same process.
=== Treatment research === The sugar cyclodextrin (CD) removed cholesterol that had built up in the arteries of mice fed a high-fat diet. CD is absorbed into the mouse bloodstream. It increases the production of oxysterols in macrophages and plaques, which causes the activation of LXR in macrophages. This, in turn, causes the macrophages to be more capable of cholesterol efflux and makes them more anti-inflammatory.
Puillandre, N.; Meyer, C.P.; Bouchet, P.; Olivera, B.M. (2011). "Genetic divergence and geographical variation in the deep-water Conus orbignyi complex (Mollusca: Conoidea)". Zoologica Scripta. 40 (4): 350–363. doi:10.1111/j.1463-6409.2011.00478.x. PMC 3123138. PMID 21712968. Puillandre, N.; Duda, T.F.; Meyer, C.; Olivera, B.M.; Bouchet, P. (2015). "One, four or 100 genera? A new classification of the cone snails". Journal of Molluscan Studies. 81 (1): 1–23. doi:10.1093/mollus/eyu055. PMC 4541476. PMID 26300576. Puillandre, N.; et al. (2014). "Molecular phylogeny and evolution of the cone snails (Gastropoda, Conoidea)". Mol. Phylogenet. Evol. 78: 290–303. Bibcode:2014MolPE..78..290P. doi:10.1016/j.ympev.2014.05.023. PMC 5556946. PMID 24878223. Reeve L (1844). "Conchologia Iconica". Monograph of the genus Conus. Vol. 1. pp. 40–47. Sowerby, G. B., II. 1833. Conus. Conchological Illustrations pls. 36–37 Taylor, J. D.; Kantor, Yu. I.; Sysoev, A. V. (1993). "Foregut anatomy, feeding mechanisms, relationships and classification of Conoidea (Toxoglossa) (Gastropoda)". Bull. Nat. Hist. Mus. 59: 125–169. Tenorio MJ, Tucker JK, Chaney HW (2012). "The Families Conilithidae and Conidae. The Cones of the Eastern Pacific". In Poppe GT, Groh K (eds.). A Conchological Iconography. Hackenheim: ConchBooks. p. 112. Tucker J.K. & Tenorio M.J. (2009), Systematic Classification of Recent and Fossil Conoidean Gastropods, ConchBooks, Hankenheim, Germany, 295 pp. Van Mol JJ, Tursch B, Kempf M (1967). "Mollusques prosobranches: Les Conidae du Brésil.
the adenovirus carrier in all samples was actually able to replicate in spite of manufacturer's declaration it was incapacitated the methodology used by Gamaleya to check immune system response was unreliable and documentation provided made its verification impossible the procedure of registering adverse effects was insufficient Anvisa delegation was also not allowed into the Gamaleya laboratory for inspection all presented studies were performed on vaccine doses produced in laboratory, rather than in the manufacturing facility supplying vaccine for the mass market, which makes the results not representative Anvisa found issues in one of the factories in Russia that could impact sterility of the doses. On 29 April 2021, the developers of Sputnik V said that Anvisa admitted not testing Sputnik V and that they would sue Anvisa in Brazil for defamation. At a press conference, Anvisa officials said that Gamaleya's own documents indicated multiple times the presence of replication-competent adenoviruses (RCAs) in ready vaccine batches and that the specifications accepted a level of RCAs 300 times greater than any other regulatory threshold. Anvisa presented the video of a meeting with representatives from Russia and Brazil where, when asked about the presence of RCAs, a representative from Russia reported problems with the cells and said that the vaccine could have been redeveloped, but it would take too long, so the developers instead chose to continue the research imposing an acceptable level of RCAs.
Sources: en.wikipedia.org
== After Liberation == Smolková-Keulemansová suffered from dysentery, jaundice, typhus and tuberculosis after liberation. She could not give an address to anyone she knew in Prague, so the International Red Cross did not allow her to return to her country of origin. To receive medical treatment, she was selected to go to Sweden for a six-month recovery stay with 6,000 other prisoners.
The most common Quechua dialect is Southern Quechua. The Kichwa people of Ecuador speak the Kichwa dialect; in Colombia, the Inga people speak Inga Kichwa. The Quechua word for a Quechua speaker is runa or nuna ("person"); the plural is runakuna or nunakuna ("people"). "Quechua speakers call themselves Runa -- simply translated, "the people". Quechua became Peru's second official language in 1969 under the military dictatorship of Juan Velasco Alvarado. There have been later tendencies toward nation-building among Quechua speakers, particularly in Ecuador (Kichwa) but also in Bolivia, where there are only slight linguistic differences from the Peruvian version. An indication of this effort is the umbrella organization of the Kichwa people in Ecuador, ECUARUNARI (Ecuador Runakunapak Rikcharimuy).
== Reactions == When heated, ammonium formate eliminates water, forming formamide. Upon further heating, it forms hydrogen cyanide (HCN) and water. A side reaction of this is the decomposition of formamide to carbon monoxide (CO) and ammonia.
In this application, ion-exchange resins are used to remove poisonous (e.g. copper) and hazardous metal (e.g. lead or cadmium) ions from solution, replacing them with more innocuous ions, such as sodium and potassium, in the process cation and anion exchange resins are used to remove dissolved ions from the water. Few ion-exchange resins remove chlorine or organic contaminants from water – this is usually done by using an activated charcoal filter mixed in with the resin. There are some ion-exchange resins that do remove organic ions, such as MIEX (magnetic ion-exchange) resins. Domestic water purification resin is not usually recharged – the resin is discarded when it can no longer be used. These ion-exchange skids that are used and sized for 10 ML/day per bead can have cost upwards of US$1.5–2.5 million when implemented for industrial water treatment. Water of highest purity is required for many uses ranging from electronics to scientific experiments, as well as the production of superconductors, and within the nuclear industry, among others. Such water is produced using ion-exchange processes or combinations of membrane and ion-exchange methods. This method can prove to be expensive as the secondary waste handling cost can run on average US$0.10–0.20 per cubic meter.
== History and etymology == The discovery of Wnt signaling was influenced by research on oncogenic (cancer-causing) retroviruses. In 1982, Roel Nusse and Harold Varmus infected mice with mouse mammary tumor virus in order to mutate mouse genes to see which mutated genes could cause breast tumors. They identified a new mouse proto-oncogene that they named int1 (integration 1). Int1 is highly conserved across multiple species, including humans and Drosophila. In 1987, researchers discovered that the int1 gene in Drosophila was actually the already known and characterized Drosophila gene known as Wingless (Wg). Since previous research by Christiane Nüsslein-Volhard and Eric Wieschaus (which won them the Nobel Prize in Physiology or Medicine in 1995) had already established the function of Wg as a segment polarity gene involved in the formation of the body axis during embryonic development, researchers determined that the mammalian int1 discovered in mice is also involved in embryonic development. Continued research led to the discovery of further int1-related genes; however, because those genes were not identified in the same manner as int1, the int gene nomenclature was inadequate. Thus, the int/Wingless family became the Wnt family and int1 became Wnt1. The name Wnt is a portmanteau of int and Wg and stands for "Wingless-related integration site".
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.