Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Sugar was first produced from sugar cane in the Indian subcontinent. Diverse species of sugar cane seem to have originated from India (Saccharum barberi and S. edule) and New Guinea (S. officinarum). Sugarcane is described in Chinese manuscripts dating to the 8th century BCE, which state that the use of sugarcane originated in India. Nearchus (admiral of Alexander the Great), the Greek physician Pedanius Dioscorides and the Roman Pliny the Elder also described sugar. In the mid-15th century, sugar was introduced into Madeira and the Canary Islands, where it was mass-produced. Christopher Columbus introduced it to the New World, leading to sugar industries in Cuba and Jamaica by the 1520s. The Portuguese took sugar cane to Brazil. Beet sugar, the starting point for the modern sugar industry, was a German invention. Beet sugar was first produced industrially in 1801 in Cunern, Prussia. Sugar became a household item by the 19th century, and this evolution of taste and demand for sugar as an essential food ingredient resulted in major economic and social changes. Demand drove, in part, the colonisation and industrialisation of previously under-developed lands. It was also intimately associated with slavery. World consumption increased more than 100 times from 1850 to 2000, led by the United Kingdom, where it increased from about 2 pounds per head per year in 1650 to 90 pounds by the early 20th century.
==== Weight-related comorbidities ==== There are over 200 obesity-related comorbidities, and it has been reported that achieving a total body weight loss of 10% has a significant impact of such conditions. Thus, the weight loss outcomes with ESG are unsurprisingly accompanied by an improvement in several obesity-related comorbidities. Weight loss facilitated by ESG has been observed to bring about benefits in or even cure of diabetes/insulin sensitivity, dyslipidemia, blood pressure, and fatty liver disease, as well as quality of life. The MERIT study showed 80% of patients who underwent ESG had improvement in one or more comorbidities at one year.
== Venom == The venom of this species is not well studied, but it is believed that the venom is dangerously neurotoxic, like that of most elapids. A study listed the intraperitoneal (IP) LD50 of this species at 0.143 mg/kg. Venoms of the water cobras were assayed for lethality, proteolytic activity and protein content. Naja annulata annulata and Naja christyi venoms averaged 89% protein and lacked proteolytic activity. The murine intraperitoneal LD50 of N. a. annulata and N. christyi venoms were 0.143 and 0.120 mg/kg, respectively. Polyvalent antivenom produced by the South African Institute of Medical Research neutralized 575 and 200 LD50 of N. a. annulata and N. christyi venoms/ml antivenom, respectively. Cation exchange chromatography resolved four lethal peaks from N. a. annulata venom and six lethal peaks from N. christyi venom. The major lethal peaks (about 12% of total venom protein) were purified further with molecular sieve chromatography and were characterized as 61- (N. a. annulata toxin) and 62-residue (N. christyi toxin) polypeptides with four half-cystines. Elucidation of the complete amino-acid sequences indicated that these toxins belonged to the short-chain class of postsynaptic neurotoxins. Short-chain neurotoxins 1 from N. a. annulata and N. christyi had murine intraperitoneal LD50 values of 0.052 and 0.083 mg/kg, respectively, and showed over 80% homology with N. nigricollis alpha toxin. Reverse-phase analysis of another peak present in both venoms resolved a toxin that had an N-terminus identical to N. christyi short-chain neurotoxin 1.
Radioactive thorium was used in the 1950s and 60s to treat tuberculosis and other benign diseases (including children), with serious consequences (see Peteosthor). A stabilized suspension of colloidal thorium(IV) oxide, co-developed by António Egas Moniz (1874-1954), was used from 1929 under the trade name Thorotrast as an X-ray contrast agent for angiography in several million patients worldwide until it was banned in the mid-1950s. It accumulates in the reticulohistiocytic system and can lead to cancer due to locally increased radiation exposure. The same is true for cholangiocarcinoma and angiosarcoma of the liver, two rare liver cancers. Carcinomas of the paranasal sinuses have also been described following administration of Thorotrast. Typical onset of disease is 30–35 years after exposure. The biological half-life of Thorotrast is approximately 400 years. The largest study in this area was conducted in Germany in 2004 and showed a particularly high mortality rate among patients exposed in this way. The median life expectancy over a seventy-year observation period was 14 years shorter than in the comparison group.
=== Photobiont === The photobiont partner of Parmotrema perlatum is from Trebouxia, a green algal genus belonging to the order Trebouxiales (order Chlorophyta). It has been identified as an undescribed species within a clade containing Trebouxia arboricola. A study compared the desiccation tolerance and physiological responses of lichenised Trebouxia to isolated cultures of the same alga. Both forms can survive extended desiccation, but with differing responses to photo-oxidative stress. Lichenisation enhances the photoprotective mechanisms of Trebouxia, improving quenching of excess light energy, particularly under high relative humidity, and controlling reactive oxygen species production under light exposure. However, isolated cultures showed better photosynthetic performance after desiccation recovery. This research demonstrates the mutual benefits of the lichen-photobiont partnership, where the alga gains a sheltered environment boosting its resilience to environmental stressors. Further studies on Parmotrema perlatum revealed specific antioxidant mechanisms supporting its photobiont under stress. The lichen shows high levels of reactive oxygen species scavenging enzymes such as superoxide dismutase and ascorbate peroxidase, protecting the photobiont from oxidative damage during dehydration and rehydration cycles. This enhanced antioxidant system provides not only physical shelter but also biochemical protection, increasing the photobiont's resilience to environmental fluctuations.
Sources: en.wikipedia.org
== Pharmacology == Pegcetacoplan acts as a complement inhibitor, specifically targeting complement protein C3, which plays a crucial role in the pathogenesis of paroxysmal nocturnal hemoglobinuria. In individuals with paroxysmal nocturnal hemoglobinuria, there is a heightened and uninhibited complement activity, which may lead to intravascular (inside blood vessels) or extravascular (within the liver or spleen) hemolysis. By binding to and inhibiting C3, pegcetacoplan helps regulate complement activation, thereby reducing red blood cell destruction, anemia, blood clot formation, and improving bone marrow function. This targeted mechanism of action makes pegcetacoplan the first-in-class medication for the treatment of paroxysmal nocturnal hemoglobinuria, offering a promising therapeutic approach to address the underlying complement dysregulation in this condition.
In 1775, the Continental Congress determined a ration that included either one pound (450 g) of beef, three-quarters pound (340 g) of pork, or one pound (450 g) of salted fish per day, as well as one pound (450 g) of flour or bread per day, one pint of milk per day, one quart of spruce beer or cider per day, three pounds (1.4 kg) of peas or beans per week, one pint of rice per week, and a small amount of molasses. However, in reality, the Continental Army had difficulties supplying its units. Congress lacked the authority to raise sufficient taxes and transportation and other supply issues compounded the problem. In reality, soldiers might receive some flour and perhaps a small amount of meat or fish. In order to preserve the food, meat was often salted and the flour would often be baked into hard biscuits. As these rations had hardly any nutrients, a weekly ration of vinegar or sauerkraut was eventually added to try to prevent scurvy, but this was insufficient. Sometimes days would pass between rations. Soldiers had to resort to foraging, with those who understood the local vegetation being able to find food in woods around the camps. At Valley Forge, watercress and sorrel were sometimes foraged to provide the troops with some vegetables. Soldiers at times had to hunt whatever animals they could find and beg civilians for food. They also bought food when possible, but this proved difficult as the Continental Army mostly paid in promissory notes which were widely distrusted and many soldiers had little goods or money to trade.
Cross-flowing is a passive formation method that involves the continuous and aqueous phases running at an angle to each other. Most commonly, the channels are perpendicular in a T-shaped junction with the dispersed phase intersecting the continuous phase; other configurations such as a Y-junction are also possible. The dispersed phase extends into the continuous and is stretched until shear forces break off a droplet. In a T-junction, droplet size and formation rate are determined by the flow rate ratio and capillary number. The capillary number relates the viscosity of the continuous phase, the superficial velocity of the continuous phase, and the interfacial tension. Typically, the dispersed phase flow rate is slower than the continuous flow rate. T-junction formation can be further applied by adding additional channels, creating two T-junctions at one location. By adding channels, different dispersed phases can be added at the same point to create alternating droplets of different compositions. Droplet size, usually above 10 μm, is limited by the channel dimensions and often produces droplets with a CV of less than 2% with a rate of up to 7 kHz.
=== Cardiac conditions === Subtypes of troponin (cardiac I and T) are sensitive and specific indicators of heart muscle damage (myocardium). They are measured in the blood to differentiate between unstable angina and myocardial infarction (heart attack) in people with chest pain or acute coronary syndrome. A person who recently had a myocardial infarction has areas of damaged heart muscle and elevated cardiac troponin levels in the blood. This can also occur in people with coronary vasospasm, a type of myocardial infarction involving severe constriction of the cardiac blood vessels. After a myocardial infarction troponins may remain high for up to 2 weeks. Cardiac troponins are a marker of all heart muscle damage, not just myocardial infarction, which is the most severe form of heart disorder. However, diagnostic criteria for raised troponin indicating myocardial infarction is currently set by the WHO at a threshold of 2 μg/L or higher. Critical levels of other cardiac biomarkers are also relevant, such as creatine kinase. Severe tachycardia (for example due to supraventricular tachycardia) in an individual with normal coronary arteries can also lead to increased troponins for example, it is presumed due to increased oxygen demand and inadequate supply to the heart muscle. Coronary artery stent placement can also cause immediate post-procedure elevated serum cardiac troponin levels. This can be problematic in a clinical setting as troponin values and guidance protocols become subject to more thoughtful interpretation.
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.