Neurotrophic signalling raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-01-22. Anything still debated is marked as such rather than presented as settled.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Manufacturing facilities must maintain a clean and hygienic manufacturing area. Manufacturing facilities must maintain controlled environmental conditions in order to prevent cross-contamination from adulterants and allergens that may render the product unsafe for human consumption or use. Manufacturing processes must be clearly defined and controlled. All critical processes are validated to ensure consistency and compliance with specifications. Manufacturing processes must be controlled, and any changes to the process must be evaluated. Changes that affect the quality of the drug are validated as necessary. Instructions and procedures must be written in clear and unambiguous language using good documentation practices. Operators must be trained to carry out and document procedures. Records must be made, manually or electronically, during manufacture that demonstrate that all the steps required by the defined procedures and instructions were in fact taken and that the quantity and quality of the food or drug was as expected. Deviations must be investigated and documented. Records of manufacture (including distribution) that enable the complete history of a batch to be traced must be retained in a comprehensible and accessible form. Any distribution of products must minimize any risk to their quality. A system must be in place for recalling any batch from sale or supply.
=== Pharmacokinetics === Esketamine is eliminated from the human body more quickly than arketamine (R(–)-ketamine) or racemic ketamine, although arketamine slows the elimination of esketamine. The half-life of esketamine was found to be approximately 5 hours. When administered intranasally, esketamine's bioavailability is approximately 30–50%.
In transgender women, breast development is a desired effect of antiandrogen and/or estrogen treatment. Bicalutamide induces breast development in individuals assigned male at birth by two mechanisms: 1) blocking androgen signaling in breast tissue; and 2) increasing estrogen levels. Estrogen is responsible for the induction of breast development under normal circumstances, while androgens powerfully suppress estrogen-induced breast growth. It has been found that very low levels of estrogen can induce breast development in the presence of low or no androgen signaling. In accordance, not only does bicalutamide induce gynecomastia at a high rate when given as a monotherapy to men with prostate cancer (38–85%; 66% in one very large trial), similarly to high-dose estrogen therapy with diethylstilbestrol (41–77%), NSAAs have been found to result in a higher incidence of gynecomastia in combination with a GnRH analogue (13–25%) relative to GnRH analogue therapy or castration alone (1–16%) (in spite of the presence of only castrate levels of estrogen in both cases). The rate of gynecomastia with CAB is also higher than with CPA monotherapy (7%). A study of men treated with NSAA (flutamide or bicalutamide) monotherapy for prostate cancer found that NSAAs induced full ductal development and moderate lobuloalveolar development of the breasts from a histological standpoint.
==== International PKU Day ==== The International PKU Day was launched in 2013 and is taking place on 28 June every year. It was inspired by the Rare Disease Day and should increase the awareness for Phenylketonuria to get featured in news. This date was chosen because of the birthdays of both Robert Guthrie (born 28 June 1916) and Horst Bickel (born 28 June 1918). As both of these people had a tremendous impact on the dietary treatment for Phenylketonuria the date proved to be the best option. In subsequence, the Robert Guthrie Memorial site was launched.
=== Chronic === Proprioception, a sense vital for rapid and proper body coordination, can be permanently lost or impaired as a result of genetic conditions, disease, viral infections, and injuries. For instance, patients with joint hypermobility or Ehlers–Danlos syndromes, genetic conditions that result in weak connective tissue throughout the body, have chronic impairments to proprioception. Autism spectrum disorder and Parkinson's disease can also cause chronic disorder of proprioception. In regards to Parkinson's disease, it remains unclear whether the proprioceptive-related decline in motor function occurs due to disrupted proprioceptors in the periphery or signaling in the spinal cord or brain. In rare cases, viral infections result in a loss of proprioception. Ian Waterman and Charles Freed are two such people that lost their sense of proprioception from the neck down from supposed viral infections (i.e. gastric flu and a rare viral infection). After losing their sense of proprioception, Ian and Charles could move their lower body, but could not coordinate their movements. However, both individuals regained some control of their limbs and body by consciously planning their movements and relying solely on visual feedback. Interestingly, both individuals can still sense pain and temperature, indicating that they specifically lost proprioceptive feedback, but not tactile and nociceptive feedback. The impact of losing the sense of proprioception on daily life is perfectly illustrated when Ian Waterman stated, "What is an active brain without mobility".
Sources: en.wikipedia.org
=== Desalination/ion separation === MOF membranes can achieve substantial ion selectivity due to their small repeating structures. This offers the potential for use in desalination and water treatment. As of 2020, reverse osmosis supplied more than two-thirds of global desalination capacity, and the last stage of most water treatment processes. Osmosis does not use dehydration of ions, or selective ion transport in biological channels and it is not energy efficient. The mining industry uses membrane-based processes to reduce water pollution, and to recover metals. MOFs could be used to extract metals such as lithium from seawater and waste streams. MOF membranes such as ZIF-8 and UiO-66 membranes with uniform subnanometer pores consisting of angstrom-scale windows and nanometer-scale cavities displayed ultrafast selective transport of alkali metal ions. The windows acted as ion selectivity filters for alkali metal ions, while the cavities functioned as pores for transport. The ZIF-8 and UiO-66 membranes showed a LiCl/RbCl selectivity of ~4.6 and ~1.8, respectively, much higher than the 0.6 to 0.8 selectivity in traditional membranes. A 2020 study suggested that a new MOF called PSP-MIL-53 could be used along with sunlight to purify water in just half an hour.
Glutamate is the most abundant excitatory neurotransmitter in the vertebrate nervous system. At chemical synapses, glutamate is stored in vesicles. Nerve impulses trigger the release of glutamate from the presynaptic cell. Glutamate acts on ionotropic and metabotropic (G-protein coupled) receptors. In the opposing postsynaptic cell, glutamate receptors, such as the NMDA receptor or the AMPA receptor, bind glutamate and are activated. Because of its role in synaptic plasticity, glutamate is involved in cognitive functions such as learning and memory in the brain. The form of plasticity known as long-term potentiation takes place at glutamatergic synapses in the hippocampus, neocortex, and other parts of the brain. Glutamate works not only as a point-to-point transmitter, but also through spill-over synaptic crosstalk between synapses in which summation of glutamate released from a neighboring synapse creates extrasynaptic signaling/volume transmission. In addition, glutamate plays important roles in the regulation of growth cones and synaptogenesis during brain development as originally described by Mark Mattson.
As early as 520 BCE, Jain philosophy, a non-creationist philosophy based on the teachings of Mahavira, stated that the universe and its constituents such as matter cannot be destroyed or created. The Jain text Tattvarthasutra (2nd century CE) states that a substance is permanent, but its modes are characterised by creation and destruction. An important idea in ancient Greek philosophy was that "Nothing comes from nothing", so that what exists now has always existed: no new matter can come into existence where there was none before. An explicit statement of this, along with the further principle that nothing can pass away into nothing, is found in Empedocles (c. 4th century BCE): "For it is impossible for anything to come to be from what is not, and it cannot be brought about or heard of that what is should be utterly destroyed." A further principle of conservation was stated by Epicurus around the 3rd century BCE, who wrote in describing the nature of the Universe that "the totality of things was always such as it is now, and always will be".
Canada is religiously diverse, encompassing a wide range of beliefs and customs. The Constitution of Canada refers to God; however, Canada has no official church and the government is officially committed to religious pluralism. Freedom of religion in Canada is a constitutionally protected right. Rates of religious adherence have steadily decreased since the 1970s. With Christianity in decline after having once been central and integral to Canadian culture and daily life, Canada has become a post-Christian, secular state. Although the majority of Canadians consider religion to be unimportant in their daily lives, they still believe in God. The practice of religion is generally considered a private matter. According to the 2021 census, Christianity is the largest religion in Canada, with Roman Catholics representing 29.9 percent of the population having the most adherents. Christians overall representing 53.3 percent of the population, are followed by people reporting irreligion or having no religion at 34.6 percent. Other faiths include Islam (4.9%), Hinduism (2.3%), Sikhism (2.1%), Buddhism (1.0%), Judaism (0.9%), and Indigenous spirituality (0.2%). Canada has the second-largest national Sikh population, behind India.
Sources: en.wikipedia.org
1894–1917 Sir Joseph Lyons 1917–1922 Montague Gluckstein 1923–1928 Alfred Salmon 1928–1941 Sir Isidore Salmon MP 1941–1950 Harry Salmon JP 1950–1956 Major Montague Isidore Gluckstein 1956–1960 Isidore Montague Gluckstein 1960–1965 Barnett Alfred Salmon 1965–1968 Sir Samuel Isidore Salmon JP (Mayor of Hammersmith 1968/69) 1968–1972 Geoffrey Salmon 1972–1977 Brian Lawson Salmon 1977–1981 Neil Lawson Salmon
== Use and effects == According to Alexander Shulgin in his book TiHKAL (Tryptamines I Have Known and Loved), DET's dose range is 50 to 100 mg orally and its duration is 2 to 4 hours. It was also assessed at oral doses of 44 to 400 mg, though 150 mg was described as "a little too much" and the 400 mg dose was simply described as "too high". Its onset is 40 minutes to more than 1 hour and peak effects occurred at just over 1 hour. In addition to oral administration, DET was assessed by smoking at doses of 40 to 90 mg, by subcutaneous injection at a dose of 40 mg, by intramuscular injection at a dose of 60 mg, and by intravenous injection at a dose of 60 mg. By these routes, it has a faster onset than when taken orally. The drug is said to taste terrible when smoked, like "burning plastic". DET was initially assumed to be inactive orally similarly to dimethyltryptamine (DMT), but this proved to be incorrect. The effects of DET have been reported to include similar "illusions" and hallucinations" as DMT, a wave-like time course of effects, closed-eye visuals, open-eye visuals, auditory and olfactory hallucinations, synesthesia, feeling like in another world, cosmic thinking, mystical and philosophical feelings, dream-like mysteriousness of objects, greater emotional significance of objects, peoples' faces seeming "mask-like", enhanced appreciation of art, architecture, and music, feeling like a small child perceiving the world and discovering it anew, time dilation, enjoyment and euphoria, increased empathy, and emotional insights.
== Awards and accolades == 1984 Elected Fellow of the National Academy of Clinical Biochemistry (now FADLM) 1988 Distinguished Scientist Award, (Clinical Ligand Assay Society) 1990-92 Co-Editor-in-Chief, Clinical Biochemistry 1996-97 President, International Clinical Ligand Assay Society 1998 Doctor of Medicine honoris causa (Leopold-Franzens-Universität Innsbruck, Austria) 1998 University of Louisville Symposium honoring the career of James L. Wittliff 2001 American Association for Clinical Chemistry (Award for Outstanding Contributions to Clinical Chemistry in a Selected Area of Research) 2001 American Association for Clinical Chemistry (Hall of Fame recognition) 2002 Interagency Coordinating Committee on the Validation of Alternative Methods/ National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods- Expert Panel 2004 Goldsmith Research Excellence Award, American Cancer Society, Kentucky Division 2008 President's Award for Career Achievements: Outstanding Scholarship, Research and Creative Activity, University of Louisville 2011 Interagency Coordinating Committee on the Validation of Alternative Methods/ National Toxicology Program Independent Scientific Peer Review Panel for the Evaluation of the LUMI-CELL® ER (BG1Luc ER TA) Test Method 2012 The CPT Paul W. Peña Outstanding Alumni Award - San Marcos Academy, San Marcos, TX 2014 Morton K.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.