lyophilised powder 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 2026-01-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
=== Neurological abnormalities === Seventy to eighty percent of cases of the most severe forms of arthrogryposis are caused by neurological abnormalities, which can be either genetic or environmental. The underlying aetiology and pathogenesis of congenital contractures, particularly arthrogryposis and the mechanism of the mutations remains an active area of investigation, because identifying these factors could help to develop treatment and congenital finding of arthrogryposis.
=== Modern electronic cigarette: 2000s === Despite these earlier efforts, Hon Lik, a Chinese pharmacist and inventor, who worked as a research pharmacist for a company producing ginseng products, is frequently credited with the invention of the modern e-cigarette. Hon quit smoking after his father, also a heavy smoker, died of lung cancer. In 2001, he thought of using a high frequency, piezoelectric ultrasound-emitting element to vaporize a pressurized jet of liquid containing nicotine. This design creates a smoke-like vapor. Hon said that using resistance heating obtained better results and the difficulty was to scale down the device to a small enough size. Hon's invention was intended to be an alternative to smoking. Hon Lik sees the e-cigarette as comparable to the "digital camera taking over from the analogue camera." Ultimately, Hon Lik did not quit smoking. He is now a dual user, both smoking and vaping.
An analog of human leptin metreleptin (trade names Myalept, Myalepta) was first approved in Japan in 2013, in the United States in February 2014, and in Europe in 2018. In the US it is indicated as a treatment for complications of leptin deficiency, and for the diabetes and hypertriglyceridemia associated with congenital or acquired generalized lipodystrophy. In Europe based on EMA, metreleptin should be used in addition to diet to treat lipodystrophy, where patients have loss of fatty tissue under the skin and build-up of fat elsewhere in the body such as in the liver and muscles. The medicine is used in adults and children above the age of 2 years with generalised lipodystrophy (Berardinelli-Seip syndrome and Lawrence syndrome); and in adults and children above the age of 12 years with partial lipodystrophy (including Barraquer-Simons syndrome), when standard treatments have failed. The National Health Service in England will commission metreleptin treatment for all with congenital leptin deficiency regardless of age beginning on April 1, 2019.
A coalition of forces opposing Iraq's aggression was formed, consisting of forces from 42 countries: Argentina, Australia, Bahrain, Bangladesh, Belgium, Canada, Czechoslovakia, Denmark, Egypt, France, Germany, Greece, Honduras, Hungary, Italy, Japan, Kuwait, Luxembourg, Morocco, the Netherlands, New Zealand, Niger, Norway, Oman, Pakistan, the Philippines, Poland, Portugal, Qatar, Romania, Saudi Arabia, Senegal, Sierra Leone, Singapore, South Korea, Spain, Sweden, Syria, Turkey, the United Arab Emirates, the UK and US. It was the largest coalition since World War II. A group of Afghan mujahideen soldiers also reportedly joined towards the end of the war. Although they did not contribute forces, Japan and Germany made financial contributions totaling $10 billion and $6.6 billion respectively. Luxembourg provided financial support. US troops represented 73% of the coalition's 956,600 troops in Iraq. A pact between the Indian government and the US also allowed US C-141 aircraft flying in materials from the Philippines to stop in Mumbai to refuel, which led to disquiet within most of the nation's formerly pro-Iraqi stance. US Army General Norman Schwarzkopf, Jr. was designated to be the commander of the coalition forces. The Soviet Union condemned Baghdad's aggression against Kuwait, but did not support the US and allied intervention in Iraq and tried to avert it. Many of the coalition countries were reluctant to commit military forces. Some felt that the war was an internal Arab affair or did not want to increase US influence in the Middle East.
Sources: en.wikipedia.org
== Appendix: Download surveys / evaluations == The AIDA developers have undertaken a range of surveys and evaluations of usage of the AIDA diabetes simulator — to better understand who is downloading the program, and why. One initial study analysed data from 1,360 downloads of the AIDA software. The intended goals of the survey were: (i) to establish the feasibility of using the Internet for auditing and surveying diabetes software users; (ii) to identify the proportion of people with diabetes and their relatives who are actually making use of the program; and (iii) to establish certain technical details about downloaders' computer setups to facilitate the distribution of upgrades to the software. 1,360 responses were received over an 8-month period (from November 1999 to July 2000). During the corresponding period 3,821 actual downloads of the software were independently logged at the Website — giving a response rate to this survey of 35.6%. Responses were received from participants in 67 countries — although over half of these (n=730, 54%) originated from the US and UK. 762 responses (56%) were received from people with diabetes and 184 (13.5%) from relatives of patients, with lesser numbers from doctors, students, diabetes educators, nurses, pharmacists, and other end users. Useful technical information about computers and operating systems being used were also obtained. The initial study established the feasibility of using the Internet to survey, at no real cost, a large number of medical software downloaders / users.
=== Modern physics === The idea of hylomorphism can be said to have been reintroduced to the world when Werner Heisenberg invented his duplex world of quantum mechanics. In his 1958 text Physics and Philosophy, Heisenberg states:
== In popular culture == In the video game Terra Invicta, the aliens attacking the Earth come to be nicknamed "hydras" due to their similarity to the real-world animal. They share a number of common traits, such as tentacles around their mouth, tissue regeneration, and lacking senescence.
Sources: en.wikipedia.org
danofloxacin – 2nd gen, related to ciprofloxacin difloxacin – 2nd/3rd gen, related to temafloxacin enrofloxacin – 2nd gen, metabolizes into ciprofloxacin ibafloxacin – 3rd gen, related to levofloxacin marbofloxacin – 3rd gen, related to levofloxacin orbifloxacin – 3rd gen, related to sparfloxacin sarafloxacin – 2nd/3rd gen, related to difloxacin pradofloxacin – 3rd gen
=== Combination hemoglobinopathies === A combination hemoglobinopathy occurs when someone inherits two different abnormal hemoglobin genes. If these are different versions of the same gene, one having been inherited from each parent it is an example of compound heterozygosity. Both alpha- and beta- thalassemia can coexist with other hemoglobinopathies. Combinations involving alpha thalassemia are generally benign. Some examples of clinically significant combinations involving beta thalassemia include:
As in the case of women, men are more prone to develop an eating disorder if their occupation or sport emphasizes having a slim physique or lighter weight, like modeling, dancing, horse racing, wrestling, and gymnastics. Hormonal changes may also be observed in males with anorexia nervosa, with marked changes in their serum testosterone, luteinizing hormone, and follicle stimulating hormone. Such extreme endocrine disturbances can potentially result in infertility. Anorexic men are sometimes colloquially referred to as manorexic or as having bigorexia.
== Contraindications == The two contraindications to taking ezetimibe are a previous allergic reaction to it, including symptoms of rash, angioedema, anaphylaxis, and severe liver disease, especially when taken with a statin. Ezetimibe may have significant medication interactions with ciclosporin and with fibrates other than fenofibrate.
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.