lyophilized 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 2025-09-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
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.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Rooty, the Great American Root Bear, originated as a prototype mascot in kids' meals in the US, but it was in Canada in 1974 that it gained further recognition, as a counter to the Ronald McDonald character of McDonald's and first appeared in the United States and in Asia shortly afterwards. However, the character's introduction was almost aborted when marketing received focus group research results that reported a poor reaction to him. In reaction, the marketing director, acting on instinct about the appeal of the character, ordered the researcher to return to Toronto with the cover story that he never presented the report. The researcher complied, and Rooty was presented to the franchisees as is. Rooty proved a popular marketing success. Rooty's adoption implied the phasing out of the Burger Family and the renaming of almost all of the burgers in the line outside of Canada. Throughout the 1970s, '80s, and '90s, Rooty was the face of A&W, both the bottled drinks and the restaurant chain, on television and print advertising. His presence all but disappeared in the late 1990s, but in 2011, under A Great American Brand's ownership, Rooty came out of retirement. He has since been featured in print ads, on A&W's website, as the voice of their official Twitter account, and in a variety of YouTube and Vine videos. A bronze statue of the bear was erected at the lobby of the current headquarters. In 2013, Rooty became the first mascot to have an official LinkedIn profile, which was quickly shut down as Rooty was not considered "real" by the authorities at Linkedin.
Harvard University's Institute of Politics Youth Poll from 2019 found that support for single-payer universal healthcare and tuition-free free college dropped, down 8% to 47% and down 5% to 51%, respectively, if cost estimates were provided. According to the Hispanic Heritage Foundation, about eight out of ten members of Generation Z identify as "fiscal conservatives." In 2018, the International Federation of Accountants released a report on a survey of 3,388 individuals aged 18 to 23 hailing from G20 countries, with a sample size of 150 to 300 per country. They found that healthcare is a top priority for Generation Z in Canada, France, Germany, and the United States. Surveys conducted in the late 2010s and early 2020s indicated that majorities of Generation Z believed that climate change was real and was caused by human activities. Differences in opinion might be due to education as younger Americans are more likely to have been taught about climate change in schools than their elders. Moreover, Generation Z broadly supports the United States transitioning away from fossil fuels and towards (next-generation) nuclear reactors and renewable energy. Majorities of this cohort also favored carbon capture and a ban on Arctic drilling. A 2018 Gallup poll found that people aged 18 to 29 have a more favorable view of socialism than capitalism, 51% to 45%. Older Americans consistently prefer capitalism to socialism.
MRC Cancer Unit Institute of Metabolic Science (IMS-MRL) Cambridge Institute for Medical Research (CIMR) Institute of Public Health Cancer Research UK Cambridge Institute MRC Mitochondrial Biology Unit
Sources: en.wikipedia.org
=== Drug target === The anticonvulsant gabapentin [Neurontin; 1-(aminomethyl)cyclohexaneacetic acid] is a drug often used to treat patients with neuropathic pain. This neuropathic pain can be caused by a number of things, including diabetic neuropathy and postherpetic neuralgia. Gabapentin is an amino acid drug structurally similar to the two neurotransmitters glutamate (synthesized by BCATs) and GABA. The drug competitively inhibits both BCAT isoforms in the brain, slowing down glutamate production. Gabapentin also inhibits GABA aminotransferase (GABA-T) and glutamate dehydrogenase (GDH), two other enzymes in the glutamate and GABA metabolic pathway.
The metabolome is the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The small molecule chemicals found in a given metabolome may include both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics) that are not naturally produced by an organism. In other words, there is both an endogenous metabolome and an exogenous metabolome. The endogenous metabolome can be further subdivided to include a "primary" and a "secondary" metabolome (particularly when referring to plant or microbial metabolomes). A primary metabolite is directly involved in the normal growth, development, and reproduction. A secondary metabolite is not directly involved in those processes, but usually has important ecological function. Secondary metabolites may include pigments, antibiotics or waste products derived from partially metabolized xenobiotics. The study of the metabolome is called metabolomics.
=== Classification === Epulis (literally, 'on the gingiva') is a general term for any gingival or alveolar tumor (i.e. lump on the gum). This term describes only the location of a lump and has no implication on the histologic appearance of a lesion. Epulis is also sometimes used synonymously with epulis fissuratum, however other conditions are classified as epulides, e.g. giant cell epulis (peripheral giant cell granuloma), ossifying fibroid epulis (peripheral ossifying fibroma), and congenital epulis.
Sources: en.wikipedia.org
=== Germany === In Germany, postgraduate medical training leading to specialization is generally referred to as Facharztweiterbildung. After obtaining the required authorization to practise medicine, physicians can apply for positions in approved hospitals and training institutions and complete specialist training while working under supervision. For international medical graduates, the pathway typically involves recognition of their medical qualifications, fulfilment of language requirements, and the applicable medical licensing process.
== Research needs == It can be difficult to apply research into OIH to average patients, because some research focused on people taking very high doses or in methadone rehabilitation programs. Opioid-induced hyperalgesia has also been criticized as overdiagnosed among chronic pain patients, due to poor differential practice in distinguishing it from the much more common phenomenon of opioid tolerance. The misdiagnosis of common opioid tolerance (OT) as opioid-induced hyperalgesia (OIH) can be problematic as the clinical actions suggested by each condition can be contrary to each other. Patients misdiagnosed with OIH may have their opioid dose mistakenly decreased (in the attempt to counter OIH) at times when it is actually appropriate for their dose to be increased or rotated (as a counter to opioid tolerance). a2 agonists, such as clonidine and dexmedetomidine, have been studied as alternatives or adjuncts to opioids for their analgesic properties in the perioperative setting. They have been shown to decrease the need for opioids after surgery, which may reduce the risk of hyperalgesic effects associated with prolonged opioid use. However, there is currently insufficient data to support the clinical effectiveness of a2 agonists in reducing postoperative OIH. Palmitoylethanolamide (PEA) has been studied for its anti-inflammatory and analgesic effects and emerging data suggests that it may have a role in delaying the onset of opioid tolerance and reducing the development of OIH when used in conjunction with opioids.
== Epidemiology == As of 2008, among adults in the United States of America older than 56, 4% were taking medication and/ or supplements that put them at risk of a major drug interaction. Potential drug-drug interactions have increased over time and are more common in the less-educated elderly even after controlling for age, sex, place of residence, and comorbidity.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.