Pro-Gly-Pro tail comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-11-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
| 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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
=== Transition zone: a changing microstructure === As solidification slows and growth kinetics become rate-limiting, the ice crystals begin to exclude the particles, redistributing them within the suspension. A competitive growth process develops between two crystal populations, those with their basal planes aligned with the thermal gradient (z-crystals) and those that are randomly oriented (r-crystals) giving rise to the start of the TZ. There are colonies of similarly aligned ice crystals growing throughout the suspension. There are fine lamellae of aligned z-crystals growing with their basal planes aligned with the thermal gradient. The r-crystals appear in this cross-section as platelets but in actuality, they are most similar to columnar dendritic crystals cut along a bias. Within the transition zone, the r-crystals either stop growing or turn into z-crystals that eventually become the predominant orientation, and lead to steady-state growth. There are some reasons why this occurs. For one, during freezing, the growing crystals tend to align with the temperature gradient, as this is the lowest energy configuration and thermodynamically preferential. Aligned growth, however, can mean two different things. Assuming the temperature gradient is vertical, the growing crystal will either be parallel (z-crystal) or perpendicular (r-crystal) to this gradient. A crystal that lays horizontally can still grow in line with the temperature gradient, but it will mean growing on its face rather than its edge.
== June 11, 1915 (Friday) == Second Battle of Artois — Despite the Germans inflicting major casualties, French advanced 500 metres (550 yd) on a 300-metre (330 yd) front towards Neuville-Saint-Vaast, France. Battle of Hébuterne — The German launched the first of two counterattacks, with the first failing to dislodge the French. Second Battle of Garua — British and French forces formally took control of all garrisons around Garua, German Cameroon. Friar Leonard Melki and hundreds of other Christians are driven out of Mardin and massacred by Ottoman troops. Born: Magda Gabor, Hungarian actress, eldest sister of the Gabor sisters which included Eva and Zsa Zsa; as Magdolna Gábor, in Budapest, Austria-Hungary (present-day Hungary) (d. 1997)
statistical genetics A branch of genetics concerned with the development of statistical methods for drawing inferences from genetic data. The theories and methodologies of statistical genetics often support research in quantitative genetics, genetic epidemiology, and bioinformatics.
== Junior career == Zverev played his first junior match in January 2011 at the age of 13 at a grade 4 tournament in Poland. Near the beginning of 2012, Zverev won his first ITF title at the Fujairah Junior Championships, a low-level Grade 4 tournament in the United Arab Emirates. He would pick up a lower level Grade 5 title at the Oman International Junior 2 a few weeks later, which led him to begin competing in higher-level events shortly before his 15th birthday. He did not have much success at tournaments that were Grade 2 and above until the following year when he reached back-to-back doubles finals with Spencer Papa at the Grade A Copa Gerdau and the Grade 1 USTA International Spring Championships. Zverev's early-season success in doubles proved to be the precursor of a major improvement in singles as well. During the European clay court season, he won his first Grade 1 title over Andrey Rublev at the Open International Junior de Beaulieu-sur-Mer. He followed up that performance with his first Grade A title at the Trofeo Bonfiglio a month later, becoming the youngest boys' singles champion in the tournament's history. He also finished runner-up at the 2013 French Open to Cristian Garín. Zverev had some grass court success as well, finishing runner-up to Nick Kyrgios at the Junior International Roehampton. However, he needed to retire at Wimbledon due to a shoulder injury. Zverev came close to reaching another major boys' singles final at the 2013 Junior US Open, but was defeated by the eventual champion Borna Ćorić in the semifinals.
Alexander George Ogston FAA FRS (30 January 1911 – 29 June 1996) was a British biochemist who specialised in the thermodynamics of biological systems. He was a grandson of Sir Alexander Ogston, a Scottish surgeon who discovered Staphylococcus.
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== Prognosis == Long-term outcomes for people with sCSFLS remain poorly studied. Symptoms may resolve in as little as two weeks as the dura mater lining heals naturally, or they can persist for months. Less commonly, patients may have unremitting symptoms for many years. People with chronic sCSFLS may be disabled and unable to work. Recurrent CSF leak at an alternate site after recent repair is common.
=== Mechanism of action === Tramadol induces analgesic effects through a variety of different targets on the noradrenergic system, serotonergic system, and opioid receptors system. Tramadol affects serotonin and norepinephrine reuptake inhibition similarly to certain antidepressants known as serotonin–norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine and duloxetine. Tramadol exists as a racemic mixture, the positive enantiomer inhibits serotonin reuptake while the negative enantiomer inhibits noradrenaline re-uptake, by binding to and blocking the transporters. Both enantiomers of tramadol are agonists of the μ-opioid receptor and its M1 metabolite, O-desmetramadol, is also a μ-opioid receptor agonist but is 6 times more potent than tramadol itself. All of these actions may work synergistically to induce analgesia.
Another notable evolutionary event of the Jurassic was the appearance of true birds, descended from maniraptoran coelurosaurians. By the Early Cretaceous and the ongoing breakup of Pangaea, dinosaurs were becoming strongly differentiated by landmass. The earliest part of this time saw the spread of ankylosaurians, iguanodontians, and brachiosaurids through Europe, North America, and northern Africa. These were later supplemented or replaced in Africa by large spinosaurid and carcharodontosaurid theropods, and rebbachisaurid and titanosaurian sauropods, also found in South America. In Asia, maniraptoran coelurosaurians like dromaeosaurids, troodontids, and oviraptorosaurians became the common theropods, and ankylosaurids and early ceratopsians like Psittacosaurus became important herbivores. Meanwhile, Australia was home to a fauna of basal ankylosaurians, titanosaurian sauropods and large and small Elasmarian ornithopods. The stegosaurians appear to have gone extinct at some point in the late Early Cretaceous or early Late Cretaceous. A major change in the Early Cretaceous, which would be amplified in the Late Cretaceous, was the evolution of flowering plants. At the same time, several groups of dinosaurian herbivores evolved more sophisticated ways to orally process food. Ceratopsians developed a method of slicing with teeth stacked on each other in batteries, and iguanodontians refined a method of grinding with dental batteries, taken to its extreme in hadrosaurids. Some sauropods also evolved tooth batteries, best exemplified by the rebbachisaurid Nigersaurus.
== Separation techniques combined with mass spectrometry == An important enhancement to the mass resolving and mass determining capabilities of mass spectrometry is using it in tandem with chromatographic and other separation techniques.
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.
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.