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 2026-01-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
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.
Sleep disturbances are common in individuals with ADHD and may arise both from the disorder itself and as an adverse effect of psychostimulant medications, which can cause delayed sleep onset and insomnia. Whilst clonidine's sedative properties, particularly in its immediate-release formulation, can limit its acceptability as a monotherapy for core ADHD symptoms during the daytime, it has been used as a sleep aid in ADHD individuals who are also treated with psychostimulants and experience insomnia. Evidence suggests that immediate-release clonidine taken at bedtime can reduce sleep-onset difficulties and night-time awakenings, but its treatment effects do not persist into the following day and it is therefore not generally effective for daytime ADHD symptoms when used in this manner.
For infecting organisms to survive and repeat the infection cycle in other hosts, they (or their progeny) must leave an existing reservoir and cause infection elsewhere. Infection transmission can take place via many potential routes: Droplet contact, also known as the respiratory route, and the resultant infection can be termed airborne disease. If an infected person coughs or sneezes on another person the microorganisms, suspended in warm, moist droplets, may enter the body through the nose, mouth or eye surfaces. Fecal-oral transmission, wherein foodstuffs or water become contaminated (by people not washing their hands before preparing food, or untreated sewage being released into a drinking water supply) and the people who eat and drink them become infected. Common fecal-oral transmitted pathogens include Vibrio cholerae, Giardia species, rotaviruses, Entamoeba histolytica, Escherichia coli, and tape worms. Most of these pathogens cause gastroenteritis. Sexual transmission, with the result being called sexually transmitted infection. Oral transmission, diseases that are transmitted primarily by oral means may be caught through direct oral contact such as kissing, or by indirect contact such as by sharing a drinking glass or a cigarette. Transmission by direct contact, Some diseases that are transmissible by direct contact include athlete's foot, impetigo and warts. Vehicle transmission, transmission by an inanimate reservoir (food, water, soil). Vertical transmission, directly from the mother to an embryo, fetus or baby during pregnancy or childbirth.
=== 28 May === The Mayor of Kyiv, Vitali Klitschko, claimed that Russian drones attacked the Ukrainian capital. Two people were killed by falling drone debris, while a woman was injured. Two high-rise apartments were set on fire. The Ukrainian Air Force claimed that 58 out of 59 drones had been shot down, with more than 40 of them intercepted over Kyiv. Fires were reported in the Solomyanskyi, Holosiivskyi and Pecherskyi Districts. The attack came on the anniversary of Kyiv's founding in 482 AD. It was later described as Russia's largest drone attack on Kyiv since the war began. Air raid alerts were activated in 12 oblasts, from Volyn in the north-west to Dnipropetrovsk in the south-east. There were also reports of explosions in Zhytomyr, where at least 26 residential buildings were damaged as well as schools and medical units. Shelling was also reported in Sumy Oblast, which borders Russia, and in Nikopol, across the Dnipro River from the Zaporizhzhia Nuclear Power Plant. Russia said its air defences shot down several drones approaching the Ilsky oil refinery in Krasnodar Krai. The Ukrainian General Staff claimed that 80 Russian soldiers deserted their positions in Lysychansk, Luhansk Oblast, while 30 others deserted from Bakhmut. Valerii Zaluzhnyi, Commander-in-Chief of the Armed Forces of Ukraine, reported that all the preparations for the anticipated major counter-attack are complete and that they were only waiting for the decision to strike.
Sources: en.wikipedia.org
== Research and career == Olabisi was a postdoctoral researcher at Rice University, where she was awarded a postdoctoral fellowship from the National Space Biomedical Research Institute, and City of Hope National Medical Center. There, she investigated how mother-of-pearl (nacre) gets its natural strength and resilience with the hope to recreate it synthetically, by patterning hydrogels with nacre proteins. Olabisi's first faculty position was at Rutgers University; today she is an assistant professor at UC Irvine. Her research looks to make wounds heal faster using cell therapy, work that could revolutionize the recovery time of people who require plastic surgery. By combining hydrogels with proteins, cellular repair can occur faster. She is an inventor on a patent describing growing bone using microencapsulated cells releasing bone morphogenetic proteins. She found that she could entrap certain cells into hydrogels to deliver the hormone insulin, which helps to heal diabetic wounds. In 2018 she became a National Science Foundation CAREER Award grant holder, exploring chronic wounds. She is working on combining mesenchymal stem cells and insulin producing cells for dual cell therapies. She has studied the way that the body adapts to the space environment, in order to identify mechanisms that protect astronauts from the effects of microgravity, by using tissue engineering approaches to stimulate growth, regeneration, and repair.
== Properties == PEEK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. The processing conditions used to mould PEEK can influence the crystallinity and hence the mechanical properties. Its Young's modulus is 3.6 GPa and its tensile strength is 90 to 100 MPa. PEEK has a glass transition temperature of around 143 °C (289 °F) and melts around 343 °C (662 °F). Some grades have a useful operating temperature of up to 250 °C (482 °F). The thermal conductivity increases nearly linearly with temperature between room temperature and solidus temperature. It is highly resistant to thermal degradation, as well as to attack by both organic and aqueous environments. It is attacked by halogens and strong Brønsted and Lewis acids, as well as some halogenated compounds and aliphatic hydrocarbons at high temperatures. It is soluble in concentrated sulfuric acid at room temperature, although dissolution can take a very long time unless the polymer is in a form with a high surface-area-to-volume ratio, such as a fine powder or thin film. It has high resistance to biodegradation.
Comatose patients may aspirate their vomit (resulting in vomitus in the lungs, which may cause "drowning" and later pneumonia if survived). CNS depression and impaired motor coordination along with poor judgment increase the likelihood of accidental injury occurring. It is estimated that about one-third of alcohol-related deaths are due to accidents and another 14% are from intentional injury. In addition to respiratory failure and accidents caused by its effects on the central nervous system, alcohol causes significant metabolic derangements. Hypoglycaemia occurs due to ethanol's inhibition of gluconeogenesis, especially in children, and may cause lactic acidosis, ketoacidosis, and acute kidney injury. Metabolic acidosis is compounded by respiratory failure. Patients may also present with hypothermia.
Sources: en.wikipedia.org
=== Technology === Building on the foundational principles of ELISA, eSimoa employs paramagnetic beads to isolate biomolecules or enzymes in a manner akin to ELISA's plate-based detection. However, eSimoa advances this concept by enabling enzymatic reaction measurements at the single-molecule level, which dramatically improves detection limits for various enzymes and biomolecules. This method allows for the precise quantification of low-abundance proteins and the activity of critical enzymes such as protein kinases and telomerases, which are often below the detection threshold of conventional ELISA.
Trump was the subject of various criminal and civil legal proceedings before and during his 2024 re-election campaign. Specifically, Trump was found liable in a civil proceeding for financial fraud in 2023, was found liable for both sexual abuse and defamation in 2023, and was found liable for defamation in a related civil proceeding in 2024. In 2024, Trump was criminally convicted of 34 felonies related to falsifying business records. Trump and other Republicans made numerous false and misleading statements regarding Trump's various legal proceedings, including false claims that they were "rigged" or consisted of "election interference" orchestrated by Biden and the Democratic Party.
=== EC 1.10.3 With oxygen as acceptor === EC 1.10.3.1: catechol oxidase EC 1.10.3.2: laccase EC 1.10.3.3: L-ascorbate oxidase EC 1.10.3.4: o-aminophenol oxidase EC 1.10.3.5: 3-hydroxyanthranilate oxidase EC 1.10.3.6: rifamycin-B oxidase EC 1.10.3.7: Now EC 1.21.3.4, sulochrin oxidase [(+)-bisdechlorogeodin-forming] EC 1.10.3.8: Now EC 1.21.3.5, sulochrin oxidase [(-)-bisdechlorogeodin-forming] EC 1.10.3.9: photosystem II EC 1.10.3.10: Now EC 7.1.1.3, ubiquinol oxidase (H+-transporting) EC 1.10.3.11: ubiquinol oxidase (non-electrogenic) EC 1.10.3.12: Now EC 7.1.1.5, menaquinol oxidase (H+-transporting) EC 1.10.3.13: Now EC 7.1.1.4, caldariellaquinol oxidase (H+-transporting) EC 1.10.3.14: Now EC 7.1.1.7, ubiquinol oxidase (electrogenic, proton-motive force generating) EC 1.10.3.15: grixazone synthase EC 1.10.3.16: dihydrophenazinedicarboxylate synthase EC 1.10.3.17: superoxide oxidase
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
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.