This is a working overview of nasal drops, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
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.
| 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 |
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Oxidation of primary alcohols or aldehydes with strong oxidants such as potassium dichromate, Jones reagent, potassium permanganate, or sodium chlorite. The method is more suitable for laboratory conditions than the industrial use of air, which is "greener" because it yields less inorganic side products such as chromium or manganese oxides. Oxidative cleavage of olefins by ozonolysis, potassium permanganate, or potassium dichromate. Hydrolysis of nitriles, esters, or amides, usually with acid- or base-catalysis. Carbonation of a Grignard reagent and organolithium reagents: RLi + CO2 → RCO−2Li+ RCO−2Li+ + HCl → RCO2H + LiCl Halogenation followed by hydrolysis of methyl ketones in the haloform reaction Base-catalyzed cleavage of non-enolizable ketones, especially aryl ketones: R−C(=O)−Ar + H2O → R−CO2H + ArH
=== Influence of contact shape === Even in the presence of perfectly smooth surfaces, geometry can come into play in form of the macroscopic shape of the contacting region. When a rigid punch with flat but oddly shaped face is carefully pulled off its soft counterpart, its detachment occurs not instantaneously but detachment fronts start at pointed corners and travel inwards, until the final configuration is reached which for macroscopically isotropic shapes is almost circular. The main parameter determining the adhesive strength of flat contacts occurs to be the maximum linear size of the contact. The process of detachment can as observed experimentally can be seen in the film.
=== Development === In at least one knock-out study of the gene, mice without thymosin β4 still had apparently normal embryonic development, and were fertile as adults (in contrast to an earlier knock-out study). This calls into some question the developmental importance of the protein.
== Types == Hemostasis can be achieved in various other ways if the body cannot do it naturally (or needs help) during surgery or medical treatment. When the body is under shock and stress, hemostasis is harder to achieve. Though natural hemostasis is most desired, having other means of achieving this is vital for survival in many emergency settings. Without the ability to stimulate hemostasis the risk of hemorrhaging is great. During surgical procedures, the types of hemostasis listed below can be used to control bleeding while avoiding and reducing the risk of tissue destruction. Hemostasis can be achieved by chemical agent as well as mechanical or physical agents. Which hemostasis type used is determined based on the situation. Developmental Haemostasis refers to the differences in the haemostatic system between children and adults.
=== Microorganisms in kimchi === The microorganisms present in kimchi include Bacillus mycoides, B. pseudomycoides, B. subtilis, Lactobacillus brevis, Lb. curvatus, Lb. kimchii, Lb. parabrevis, Lb. pentosus, Lb. plantarum, Lb. sakei, Lb. spicheri, Lactococcus carnosum, Lc. gelidum, Lc. lactis, Leuconostoc carnosum, Ln. citreum, Ln. gasicomitatum, Ln. gelidum, Ln. holzapfelii, Ln. inhae, Ln. kimchii, Ln. lactis, Ln. mesenteroides, Serratia marcescens, Weissella cibaria, W. confusa, W. kandleri, W. kimchii. W. koreensis, and W. soli. Archaea and yeasts, such as Saccharomyces, Candida, Pichia, and Kluyveromyces are also present in kimchi, with the latter being responsible for undesirable white colonies that sometimes form in the product as well as food spoilages and off-flavors. In early fermentation stages, the Leuconostoc variety is found more dominantly in kimchi fermentation because of its lower acid tolerance and microaerophilic properties; the Leuconostoc variety also grows better at low salt concentrations. Throughout the fermentation process, as acidity rises, the Lactobacillus and Weissella variety become dominant because of their higher acid tolerance. Lactobacillus also grows better in conditions with a higher salt concentration. These microorganisms are present due to the natural microflora provided by utilizing unsterilized food materials in the production of kimchi.
Sources: en.wikipedia.org
=== Democratic constitution, NATO and European Union memberships === There were several post-Solidarity governments between the 1989 election and the 1993 election, after which the "post-communist" left-wing parties took over. In 1993, the formerly Soviet Northern Group of Forces, a vestige of past domination, left Poland. In 1995, Aleksander Kwaśniewski of the Social Democratic Party was elected president and remained in that capacity for the next ten years (two terms). In 1997, the new Constitution of Poland was finalized and approved in a referendum; it replaced the Small Constitution of 1992, an amended version of the communist constitution. Poland joined NATO in 1999. Elements of the Polish Armed Forces have since participated in the Iraq War and the War in Afghanistan (2001–2021). Poland joined the European Union as part of its enlargement in 2004. However, Poland has not adopted the euro as its currency and legal tender, but instead uses the Polish złoty. In April 2010, Polish president Lech Kaczynski and dozens of the country's top political and military leaders died in the Smolensk air disaster. After the election of the far-right conservative Law and Justice party in 2015, the Polish government repeatedly clashed with EU institutions on the issue of judicial reform and was accused by the European Commission and the European Parliament of undermining "European Values" and eroding democratic standards.
Balance of terror Balance of threat Mutual assured destruction – a theory in which two or more states are balanced by their ability to effectively completely destroy each other Negarchy Offshore balancing Peace through strength Polarity (international relations) Soft balancing Sphere of influence Superpower Strategic autonomy In history:
=== Phase 1 === (R)-MDMA ((R)-midomafetamine; MM-402) – serotonin, norepinephrine, and dopamine releasing agent and weak serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptor agonist (entactogen and weak psychedelic hallucinogen) STP-1 (STALICLA Therapeutic Package 1) – phosphoric diester hydrolase inhibitor and sodium–potassium–chloride symporter inhibitor Sulforafan alfadex (sulforaphane alfadex; sulforafan α-cyclodextrin; SFX-01, STP-2; broccoli sprout extract) – various actions
=== Digestive system === Arenobufagin has shown to cause appoptose in hepatocellular carcinoma cells in mice, although this method is not used to cure hepatocellular carcinoma in modern human medicine.
Sources: en.wikipedia.org
== Effect on cancer == Initially, MAFs were thought to increase a macrophage’s cytotoxic response, allowing enhanced clearance of the tumor cells. However, they also have wider ranging effects. Chronic inflammation associated with activated macrophages may lead to the development of neoplasia, such as those found surrounding tuberculosis scars. Dysregulation of macrophage activation may cause increased inflammation and eventual neoplasia. Moreover, macrophages infiltrating the tumor microenvironment can transition towards a regulatory phenotype. Regulatory macrophages produce Interleukin 10, which can inhibit cytotoxic responses of other lymphocytes to cancer cell antigens. The stromal reaction surrounding a tumor, as well as prostaglandins and hypoxia may play a role in this transition. Epithelial-mesenchymal transition has been found to be influenced by all types of macrophages, which cause both pro and anti-inflammatory responses that can promote EMT.
== Fourth- and fifth-hand smoke == More controversially, the related concepts of fourth-hand smoke and even fifth-hand smoke have also been proposed as well to refer to further orders of theoretical contamination from tobacco smoke.
12 May Data from the Office for National Statistics indicates the UK economy grew by 0.1% between January and March 2023, with ongoing strike action and the cost of living crisis contributing to the smaller than expected growth. Following a three-week trial at Newcastle Crown Court, David Boyd is convicted of the October 1992 murder of Nikki Allan in Sunderland. 13 May An inquiry is launched into possible "intentional damage" of a Royal Navy warship after around 60 cables were cut on HMS Glasgow at Scotstoun on the River Clyde. The final of the 2023 Eurovision Song Contest takes place in Liverpool. The contest is won by Sweden's Loreen with the song "Tattoo", who becomes only the second person and the first woman to win the contest twice. The United Kingdom's Mae Muller finishes 25th with her song "I Wrote a Song". 14 May – Former Archbishop of York Lord Sentamu is forced to resign his position as an assistant bishop in the Church of England Diocese of Newcastle following a report that criticised his handling of a child sex abuse case during his tenure as Archbishop of York. 15 May The sixteen heraldic shields of the British Overseas Territories and the three coat of arms of the Crown Dependencies are "immortalised" in two new stained glass windows, unveiled in the Speaker's House at the New Palace of Westminster. House of Commons Speaker, Sir Lindsay Hoyle said "The two windows represent part of our United Kingdom family". Ukrainian president Volodymyr Zelensky visits the UK to hold talks with Prime Minister Rishi Sunak.
1930: Mexican civil engineer Concepción Mendizábal Mendoza became the first woman in Mexico to earn a civil engineering degree. 1930: Russian botanist and geneticist Elena Barulina published the first map of the international distribution of lentils and their wild relatives, a work that became the standard reference for researchers. 1932: Michiyo Tsujimura became the first Japanese woman to earn a doctorate in agriculture. She studied at the Tokyo Imperial University, and her doctoral thesis was entitled "On the Chemical Components of Green Tea". 1933: Hungarian scientist Elizabeth Rona received the Haitinger Prize from the Austrian Academy of Sciences for her method of extracting polonium. 1933: American bacteriologist Ruth Ella Moore became the first African-American woman to receive a PhD in the natural sciences, completing her doctorate in bacteriology at Ohio State University. 1933: Egyptian medical doctor Tawhida Abdel-Rahman became the first female doctor employed by the Egyptian Government Health Ministry. 1935: French chemist Irène Joliot-Curie received the Nobel Prize in Chemistry along with Frédéric Joliot-Curie "for their synthesis of new radioactive elements". 1935: American plant hybridist Grace Sturtevant, the "First Lady of Iris", received the American Iris Society's gold medal for her lifetime's work. 1936: American entomologist Edith Patch became the first female president of the Entomological Society of America. 1936: New Zealand mycologist Kathleen Maisey Curtis was elected the first female Fellow at the Royal Society of New Zealand.
(1914–2006), American physicist and chemist who won the 2002 Nobel Prize in Physics for detecting neutrinos emitted from the Sun Humphry Davy (1778–1829), British chemist, discovered several alkaline earth metals Serena DeBeer (born 1973), American chemist known for developing X-ray based spectroscopic probes of electronic structure Peter Debye (1884–1966), Dutch chemist who improved the theory of electrical conductivity in electrolyte solutions, winner of the 1936 Nobel Prize in Chemistry Johann Deisenhofer (born 1943), German biochemist who determined the three-dimensional structure of a protein complex found in photosynthetic bacteria, 1988 Nobel Prize in Chemistry Margarita del Val (born 1959), Spanish chemist, immunologist, and virologist, coordinator of the Salud Global ("Global Health") platform Nathalie Demassieux (1884–1961), French mineral chemist and academic who worked on the complex halogenated salts of lead Gautam Radhakrishna Desiraju (born 1952), Indian chemist known for work on crystal engineering and weak hydrogen bonds James Dewar (1842–1923), British chemist and physicist known for his invention of the vacuum flask and its usefor studying the liquefaction of gases François Diederich (1952–2020), Luxembourg chemist known for molecular recognition studies with biological receptors Otto Diels (1876–1954), German chemist, winner of the 1950 Nobel Prize in Chemistry for the Diels–Alder reaction, a method for cyclohexene synthesis Robert Dirks (1978–2015), American computational chemist known for work on DNA nanotechnology
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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.