intranasal delivery raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-11-28 and is reviewed periodically as new material appears.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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 |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
The Berlin Blockade of 1948 to 1949 was an early confrontation, as was the Korean War of 1950 to 1953, which ended in a stalemate. US involvement in regime change during the Cold War included support for First World anti-communist and right-wing dictatorships and uprisings, while Soviet involvement included the funding of Second World left-wing parties, wars of independence, and dictatorships. As nearly all the colonial states underwent decolonization, many became Third World battlefields of the Cold War. Both powers used economic aid in an attempt to win the loyalty of non-aligned countries. The Cuban Revolution of 1959 installed the first communist regime in the Western Hemisphere, and in 1962, the Cuban Missile Crisis began after deployments of US missiles in Europe and Soviet missiles in Cuba; it is widely considered the closest the Cold War came to escalating into nuclear war. Another major proxy conflict was the Vietnam War of 1955 to 1975, which ended in a North Vietnamese victory. The USSR solidified its domination of Eastern Europe with its crushing of the Hungarian Revolution in 1956 and the Warsaw Pact invasion of Czechoslovakia in 1968. Relations between the USSR and China broke down by 1961, with the Sino-Soviet split bringing the two states to the brink of war amid a border conflict in 1969. In 1972, the US initiated diplomatic contacts with China and the US and USSR signed a series of treaties limiting their nuclear arsenals during a period known as détente.
Further, during the first year of the COVID-19 pandemic, overdose disparities widened between Black persons and White persons. For example, in 2020, overdose rates among Black men 65 years or older (52.6 per 100 000) were nearly 7 times those of White men of the same age (7.7 per 100 000). During times of economic distress such as the COVID-19 pandemic or the 2008 recession, harmful rates of drug use has been seen to increase in populations experiencing joblessness and disadvantaged populations; moreover, Carpenter et al. found evidence that economic downturns lead to increases in the intensity of prescription pain reliever use as well as increases in clinically significant substance use disorders involving opioids. In addition, the COVID-19 pandemic has marked the start of health care policies that, should they be adopted permanently, could not only lessen the effects of the pandemic on overdoses, but also make overall treatment of opioid use disorder more effective by eliminating obstacles to previously proven therapies for these disorders. Other studies have looked at treatments for OUD during the COVID-19 pandemic. For example, one JAMA Internal Medicine research letter from December 2020 found that since the COVID-19 national emergency declaration, "the number of individuals filling buprenorphine prescriptions has plateaued but has not decreased; however, filled prescriptions for all medications collectively have decreased considerably."
== Consensus Development Program == The Consensus Development Program is an initiative focused on gathering expert opinions to establish standards and guidelines in various fields, especially in health and medicine. Developed as a collaborative effort by organizations such as the NIH, the program assembles panels of specialists who assess available evidence on critical topics and form recommendations to guide clinical practice and policy. This method helps ensure that healthcare decisions are informed by the latest scientific research and expert consensus.
Sources: en.wikipedia.org
Alprazolam, sold under the brand name Xanax among others, is a fast-acting, potent tranquilizer of moderate duration within the triazolobenzodiazepine group of chemicals called benzodiazepines. Alprazolam is most commonly prescribed in the management of anxiety disorders, especially panic disorder and generalized anxiety disorder (GAD). Other uses include the treatment of chemotherapy-induced nausea, together with other treatments. Alprazolam is generally taken orally. Common side effects include sleepiness, depression, suppressed emotions, mild to severe decreases in motor skills, hiccups, dulling or declining of cognition, decreased alertness, dry mouth (mildly), decreased heart rate, impairment of judgment (usually in higher than therapeutic doses), and decreased memory formation, depending on dosage. Some of the sedation and drowsiness may improve within a few days. Benzodiazepine withdrawal symptoms may occur if use is suddenly decreased. Alprazolam was developed by Jackson Hester Jr. at the Upjohn Company and patented in 1971 and approved for medical use in the United States in 1981. Alprazolam is a Schedule IV controlled substance and is a common drug of abuse. It is available as a generic medication. In 2023, it was the 37th most commonly prescribed medication in the United States, with more than 15 million prescriptions.
Well-known disorders caused by thiamine deficiency include beriberi, Wernicke–Korsakoff syndrome, optic neuropathy, Leigh's disease, African seasonal ataxia (or Nigerian seasonal ataxia), and central pontine myelinolysis. Symptoms include malaise, weight loss, irritability and confusion. In Western countries, chronic alcoholism is a risk factor for deficiency. Also at risk are older adults, persons with HIV/AIDS or diabetes, and those who have had bariatric surgery. Varying degrees of thiamine insufficiency have been associated with the long-term use of diuretics.
During the War of the Triple Alliance, Peru was a country that protested against the alleged attempts to conquer Paraguay by the member countries of the Triple Alliance (of which Argentina was a part together with Uruguay and Brazil). For the rest of the continent, this war was perceived as an attempt to conquer and divide Paraguay among the allies. The attempt against the independence of one of the countries of the continent was feared as a terrible precedent for potential geopolitical disorders and possible expansionist projects in the governments of the area, Argentina being very frowned upon in the eyes of Peru. The controversial Secret Treaty of the Triple Alliance was seen in Peruvian diplomacy as a violation of Paraguay's sovereignty and integrity as a country. Thus, the perception of that war was understood, in the public eye, as the arrogance of 3 allied countries that wanted to seize Paraguay's territory and even destroy its sovereignty, generating analogies with the Second French intervention in Mexico or the Spanish-South American War, that happened simultaneously during the 1860s, comparing them as a form of imperialism not different from that of the Europeans. Seen in this way, no distinction was made regarding a conquest, especially of a Latin American country, by an American government or a European government, in the eyes of society, both acts were reprehensible.
High-throughput experimentation involves increasing throughput by scaling up the number of experiments that can be run in parallel using a common sample form factor and technique. When space or materials are limited, minor factors must be assigned to progressively smaller fractions to increase the number of replicates. Cloud labs, on the other hand, do not fundamentally scale up a single experiment but rather increase the number of types of experiments that can be run in parallel. For example, with a cloud lab, a scientist could simultaneously attempt dozens of different purification methods that each uses completely unique equipment sets. HTE work cells can sometimes be accessed remotely to trigger a run on a library or digitally monitor a run. However, this remote monitoring or screen triggering does not impact the development that must take place in advance of a run. Often with HTE, scientists must group samples into libraries that use the same or very similar form factor containers such that the work cell can more easily traffic and address each sample in an integrated manner. Therefore, scientists need to standardize sample form factors of samples and handle the sample prep offline of the work cell. Cloud labs can work with samples in hundreds or even thousands of unique containers, providing additional flexibility relative to traditional labs (even those that are using HTE), and allowing processing of a larger number of samples.
Sources: en.wikipedia.org
Freon is a trademark of the DuPont Corporation and refers to these CFCs, and later hydro chlorofluorocarbon (HCFC) and hydro fluorocarbon (HFC), refrigerants developed in the late 1920s. These refrigerants were considered — at the time — to be less harmful than the commonly used refrigerants of the time, including methyl formate, ammonia, methyl chloride, and sulfur dioxide. The intent was to provide refrigeration equipment for home use without danger. These CFC refrigerants answered that need. In the 1970s, though, the compounds were found to be reacting with atmospheric ozone, an important protection against solar ultraviolet radiation, and their use as a refrigerant worldwide was curtailed in the Montreal Protocol of 1987.
== Freezable tissues and organs == Generally, cryopreservation is easier for thin samples and suspended cells, because these can be cooled more quickly and so require lesser doses of toxic cryoprotectants. Therefore, tissue cryopreservation of human livers and hearts (organ cryopreservation) for storage and transplant is still impractical or experimental. Most organs are usually preserved at a temperature of just above 0°C, which allows them to be stored for a few hours to a few days. Certain organs may be preserved at temperatures between -20°C to -50°C, enabling storage for a few weeks to a few months. In 2023, researchers successfully cryopreserved rat kidneys at -196°C using liquid nitrogen for 100 days. With suitable combinations of cryoprotectants and regimes of cooling and rinsing during warming often allow the successful cryopreservation of biological materials, particularly cell suspensions or thin tissue samples. At -196 °C using liquid nitrogen, tissues and organs can be preserved for a long period, often more than a decade. Examples include:
Internationally, DMT is a Schedule I drug under the Convention on Psychotropic Substances. The Commentary on the Convention on Psychotropic Substances notes, however, that the plants containing it are not subject to international control:
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
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.