If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
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.
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.
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.
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.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
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.
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.
== G == galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide b-1,6-N-acetylglucosaminyltransferase - galactosylgalactosylglucosylceramidase - GalP (protein) - GATA zinc finger - gel electrophoresis - gel shift - gel shift assay - gene - gene amplification - gene conversion - gene expression - gene mapping - gene pool - gene therapy - gene transfer - genetic code - genetic counseling - genetic map - genetic marker - genetic screening - genetically modified mouse - genome - genomic blot - genomic clone - genomic library - genotype - geranylgeraniol 18-hydroxylase - germ line - germacrene A alcohol dehydrogenase - gluconate 2-dehydrogenase - glutamate permease - glycerol-3-phosphate-transporting ATPase - glycoprotein - glycosylation - Golgi apparatus - GRE - guanine - guanine-transporting ATPase -
On 10 January 1972, an ad hoc strike committee led by Johannes Nangutuuala, was formed to negotiate with the South African government; the strikers demanded an end to contract labour, freedom to apply for jobs according to skill and interest and to quit a job if so desired, freedom to have a worker bring his family with him from Ovamboland while taking a job elsewhere, and for equal pay with white workers. The strike was later brought to an end after the South African government agreed to several concessions which were endorsed by Nangutuuala, including the implementation of uniform working hours and allowing workers to change jobs. Responsibility for labour recruitment was also transferred to the tribal authorities in Ovamboland. Thousands of the sacked Ovambo workers remained dissatisfied with these terms and refused to return to work. They attacked tribal headmen, vandalised stock control posts and government offices, and tore down about a hundred kilometres of fencing along the border, which they claimed obstructed itinerant Ovambos from grazing their cattle freely. The unrest also fueled discontent among Kwanyama-speaking Ovambos in Angola, who destroyed cattle vaccination stations and schools and attacked four border posts, killing and injuring some SADF personnel as well as members of a Portuguese militia unit. South Africa responded by declaring a state of emergency in Ovamboland on 4 February.
mistranslation The insertion of an incorrect amino acid in a growing peptide chain during translation, i.e. the inclusion of any amino acid that is not the one specified by a particular codon in an mRNA transcript. Mistranslation may originate from a mischarged transfer RNA or from a malfunctioning ribosome.
Sources: en.wikipedia.org
Pre-adipocytes are undifferentiated fibroblasts that can be stimulated to form adipocytes. Studies have shed light into potential molecular mechanisms in the fate determination of pre-adipocytes although the exact lineage of adipocyte is still unclear. The variation of body fat distribution resulting from normal growth is influenced by nutritional and hormonal status dependent on intrinsic differences in cells found in each adipose depot. Mesenchymal stem cells can differentiate into adipocytes, connective tissue, muscle or bone. The precursor of the adult cell is termed a lipoblast, and a tumor of this cell type is known as a lipoblastoma.
Specifically when set up in a loop with a buffering liquid between the incoming and outgoing fluid running in a circuit, and with active transport pumps on the outgoing fluid's tubes, the system is called a countercurrent multiplier, enabling a multiplied effect of many small pumps to gradually build up a large concentration in the buffer liquid. Other countercurrent exchange circuits where the incoming and outgoing fluids touch each other are used for retaining a high concentration of a dissolved substance or for retaining heat, or for allowing the external buildup of the heat or concentration at one point in the system. Countercurrent exchange circuits or loops are found extensively in nature, specifically in biologic systems. In vertebrates, they are called a rete mirabile, originally the name of an organ in fish gills for absorbing oxygen from the water. It is mimicked in industrial systems. Countercurrent exchange is a key concept in chemical engineering thermodynamics and manufacturing processes, for example in extracting sucrose from sugar beet roots. Countercurrent multiplication is a similar but different concept where liquid moves in a loop followed by a long length of movement in opposite directions with an intermediate zone. The tube leading to the loop passively building up a gradient of heat (or cooling) or solvent concentration while the returning tube has a constant small pumping action all along it, so that a gradual intensification of the heat or concentration is created towards the loop.
Marlowe (1988), creator of Castle; writer of Air Force One, End of Days, and Hollow Man Lawrence Trilling (1988), showrunner of Parenthood and Goliath Maiken Baird (1989), documentary film producer, Client 9: The Rise and Fall of Eliot Spitzer Sam Bisbee (1990), Emmy Award-winning producer and composer Gina Fattore (1990), producer and writer of Dawson's Creek, Gilmore Girls, Parenthood, creator of Dare Me Jeff Rake (1990), television producer, writer of Boston Legal and creator of Manifest and The Mysteries of Laura Dede Gardner (1990), Academy Award-winning producer of 12 Years a Slave; president of Plan B Entertainment Jenji Kohan (1991), television writer, producer, creator of Orange Is the New Black and Weeds Ari Gold (1992), filmmaker, director of Adventures of Power Elizabeth Craft (1993), producer, screenwriter, Fantasy Island, The 100, Lie to Me Ethan McSweeny (1993), former artistic director of the American Shakespeare Center, recipient of a 2018 Helen Hayes Award Brian Yorkey (1993), playwright, co-winner of the 2010 Pulitzer Prize for Drama for writing the musical Next to Normal Anna Winger (1993), screenwriter, creator of miniseries Deutschland 83, Deutschland 86, and Unorthodox Imara Jones (1994), political journalist and director Nicole Kassell (1994), director and producer of Watchmen, winner of the 2020 Directors Guild of America Award for Outstanding Directing – Drama Series Tim Carvell (1995), head writer of The Daily Show and executive producer of Last Week Tonight with John Oliver Josh Fox (1995), Academy Award-nominated documentary director, Gasland Adam Egypt Mortimer (1995), director of Daniel Isn't Real, Archenemy Henry Alex Rubin (1995), Academy Award-nominated director, Murderball Julius Sharpe (1995), television writer and showrunner of Making History and United We Fall Ramin Bahrani (1996), writer-director of Man Push Cart, Chop Shop and Fahrenheit 451, 2021 Academy Award for Best Adapted Screenplay nominee Moira Demos (1996), filmmaker who produced Netflix documentary Making a Murderer Yana Gorskaya (1996), Academy Award-nominated film editor, Spellbound Cetywa Powell (1996), director and fine art photographer Courtney Lilly (1997), television producer, showrunner of Black-ish, Grown-ish, Mixed-ish Nancy Schwartzman (1997), director, Roll Red Roll Beau Willimon (1999), creator and producer of House of Cards; writer of the play Farragut North Vikram Gandhi (2000), director, Kumaré, Barry, reporter for Vice Andrew Goldberg (2000), creator of Netflix series Big Mouth Ned Benson (2001), director, The Disappearance of Eleanor Rigby Dan Harris (2001), Saturn Award-winning screenwriter, X2, Superman Returns; director, Imaginary Heroes Andrew Neel (2001), filmmaker, director of King Kelly, Goat Anna Boden (2002), co-writer of Half Nelson and director of Sugar, Captain Marvel Tze Chun (2002), award-winning director, Children of Invention Lang Fisher (2002), co-creator of Never Have I Ever, writer of 30 Rock and Brooklyn Nine-Nine, Peabody Award winner in 2008 Susanna Fogel (2002), Emmy Award and BAFTA Award-nominated director Will Graham (2002), creator of the Onion News Network, showrunner of Mozart in the Jungle, Peabody Award winner in 2008 Ashley Lyle (2002), screenwriter, showrunner of Yellowjackets Justin Marks (2002), screenwriter, The Jungle Book, Counterpart Katori Hall (2003), playwright, The Mountaintop, winner of the 2021 Pulitzer Prize for Drama Raamla Mohamed (2003), Emmy Award-nominated screenwriter, Little Fires Everywhere Graham Moore (2003), winner of the 2015 Academy Award for Best Adapted Screenplay for his screenplay of The Imitation Game Lucia Aniello (2004), director of Rough Night and Time Traveling Bong Gabe Liedman (2004), creator of Q-Force, writer of Brooklyn Nine-Nine, PEN15, Inside Amy Schumer and Kroll Show Zhang Mo (2005), Chinese director, daughter of Zhang Yimou Laura Goode (2006), author, columnist, and producer of Farah Goes Bang Matt Kaplan (2006), producer of young adult films, To All the Boys franchise Meera Menon (2006), Indian-American director, Equity Lilly Burns (2009), television producer, co-founder of Jax Media and president of Imagine Entertainment Eli Bush (2009), film and theatre producer and winner of the Golden Globe Award in 2018 for Lady Bird Jason Fuchs (2009), actor and screenwriter, Pan, Ice Age: Continental Drift Jessica Kingdon (2009), Academy Award-nominated Chinese-American documentary director Nuotama Bodomo (2010), Ghanaian filmmaker and co-writer of sketch comedy Random Acts of Flyness on HBO Sabaah Folayan (2013), director of documentary Whose Streets?
=== Test to Stay === SHIELD Illinois piloted the "Test to Stay" program developed in cooperation with the Illinois Department of Public Health. Later endorsed by the CDC, Test to Stay allows unvaccinated students, faculty, and staff who have been exposed to SARS-CoV-2 positive individuals to remain in the classroom providing they wear a mask and test on days one, three, five, and seven following exposure. This program prevented the need to quarantine and exclude entire classes when one student in the group tests positive. During the pilot period alone, which only covered a population of 1,035 students and staff, "8,152 learning days were saved among close contacts."
Sources: en.wikipedia.org
The first fully synthetic opioid was meperidine (Demerol), found serendipitously by German chemist Otto Eisleb (or Eislib) at IG Farben in 1932. Meperidine was the first opioid to have a structure unrelated to morphine, but with opioid-like properties. Its analgesic effects were discovered by Otto Schaumann in 1939. Gustav Ehrhart and Max Bockmühl, also at IG Farben, built on the work of Eisleb and Schaumann. They developed "Hoechst 10820" (later methadone) around 1937. In 1959 the Belgian physician Paul Janssen developed fentanyl, a synthetic opioid with 30 to 50 times the potency of heroin. Nearly 150 synthetic opioids are now known.
== History == Elagolix was first described in the literature in 2005. It was originally developed by the pharmaceutical company Neurocrine Biosciences, and was later developed together by Neurocrine Biosciences and AbbVie (previously Abbott Laboratories). In June 2010, Neurocrine Biosciences and Abbott announced a global agreement to develop and commercialize elagolix for the treatment of endometriosis. The medication completed phase III clinical trials for endometriosis in November 2016. Two phase III clinical trials, the Elaris Endometriosis I and II (EM-I and EM-II) studies, were conducted. The studies included almost 1,700 women, about 950 of whom were treated with elagolix. In September 2017, AbbVie filed a New Drug Application (NDA) for elagolix for the treatment of pain associated with endometriosis in the United States. The medication was approved by the FDA for the treatment of endometriosis-associated pain in the United States on 23 July 2018. It was the first new medication to be approved by the FDA for the treatment of endometriosis in more than a decade. Elagolix was the first member of a new class of GnRH modulators described as "second-generation" due to their non-peptide and small-molecule nature and oral activity to be marketed. A second member of this group, relugolix (brand name Relumina), was introduced in Japan in January 2019. In addition to endometriosis, elagolix is under development for the treatment of uterine fibroids and menorrhagia. It is in phase III clinical trials for these indications.
29 July – Prime Minister Rishi Sunak urges Mayor of London Sadiq Kahn to reconsider his plans to expand the Ultra Low Emission Zone, describing it as an "unnecessary extra tax". 30 July – Grime artist Stormzy and HSBC announce an extension of the Stormzy Scholarships scheme, with funding for a further 36 places for black students at Cambridge University. Each student will receive a £20,000 annual scholarship. 31 July – The National Education Union says that its members have voted to accept the UK government's 6.5% pay offer for teachers in England, with 86% of those voting in favour of the increase. Wild camping is to be allowed on Dartmoor once again after the National Park Authority wins a legal challenge against its suspension.
=== De novo sequencing === The pattern of fragmentation of a peptide allows for direct determination of its sequence by de novo sequencing. This sequence may be used to match databases of protein sequences or to investigate post-translational or chemical modifications. It may provide additional evidence for protein identifications performed as above.
the person responsible under § 115 StrlSchG (in German) paragraph 2 or § 153 StrlSchG (in German) paragraph 1. The SSR numbers must then be available for further use as part of normal communication with monitoring stations or radiation pass authorities. The SSR number is derived from the social security number and personal data using non-traceable encryption. The transmission takes place online. Approximately 420,00 persons are monitored for radiation protection in Germany (as of 2019). Emergency responders (including volunteers) who are not occupationally exposed persons within the meaning of the Radiation Protection Act also require an SSR number retrospectively, i.e. after an operation in which they were exposed to radiation above the limits specified in the Radiation Protection Ordinance, as all relevant exposures must be recorded in the Radiation Protection Register.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.