The short version of Melanocortin receptor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
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.
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
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.
The androgen backdoor pathways are vital for creating androgens from 21-carbon (C21) steroids, known as pregnanes. A 21-carbon steroid is a steroid molecule with 21 carbon atoms, hence, their chemical formula contains C21. For example, the chemical formula of progesterone is C21H30O2. For this reason, 21-carbon steroids are denoted as C21-steroids, 19-carbon steroids are denoted as C19 steroids, and so on. The androgen backdoor pathways occur without the involvement of testosterone (T) and/or androstenedione (A4), which are part of the conventional, canonical (classic) androgenic pathway. In the canonical pathways of androgen biosynthesis, DHT is synthesized from T via 5α-reduction, so that 5α-reduction of T, a C19 steroid, is the last step of the pathway (see Dihydrotestosterone § Biosynthesis). In the backdoor pathways, to the contrary, 5α-reduction of C21 steroids is the first step. The 5α-reduction is a chemical reaction where a functional group attached to the carbon in position 5α of the steroid nucleus is reduced, and a double bond between carbon atoms numbered 4 and 5 in the steroid molecule is replaced to the single bond in a chemical reaction catalyzed by the SRD5A1 enzyme. The androgen backdoor pathways can be also activated in pathologic conditions (diseases), such as congenital adrenal hyperplasia (CAH), leading to hyperandrogenism.
Some patients who have their blood pressure measured in a clinical setting have higher readings than they do when measured in a home setting. This is apparently a result of patients feeling more relaxed when they are at home. The phenomenon is sometimes called white coat hypertension, in reference to the traditional white coats worn in a clinical setting, though the coats themselves may have nothing to do with the elevated readings.
PEPAP (phenethylphenylacetoxypiperidine) is an opioid analgesic that is an analog of desmethylprodine. It is related to the drug MPPP, with an N-phenethyl group in place of the N-methyl substitution and an acetate ester rather than propionate. PEPAP is approximately 6–7 times more potent than morphine in laboratory rats. PEPAP presumably has similar effects to other opioids, producing analgesia, sedation and euphoria. Side effects can include itching, nausea and potentially serious respiratory depression which can be life-threatening. PEPAP has been found to be a potent CYP2D6 inhibitor, which makes it likely to cause adverse interactions with some other drugs, although the inhibitory potency of PEPAP is less than that of MPPP. Both cocaine and methadone are also CYP2D6 inhibitors and could, in theory, potentiate the effect. It is unlikely that the tetrahydropyridine byproducts that may be formed during the synthesis of PEPAP are neurotoxic in the same way as the MPPP byproduct MPTP. It appears that the N-methyl group of MPTP is required for neurotoxic activity. In animal experiments, only MPTP analogues that preserved the N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine structure were active as dopaminergic neurotoxins. Most structural changes, including replacing the N-methyl group with other substituents, abolished neurotoxicity. There is evidence that the clandestine manufacturers who produced MPPP in the 1970s, including the tainted batch, went on to produce PEPAP in an attempt to avoid using watched precursors or drug intermediates that were illegal.
=== Film and television === Six months prior to his graduation from Guildhall, McGregor began a leading role in Dennis Potter's six-part Channel 4 series Lipstick on Your Collar (1993). He then starred in the BBC adaptation of Scarlet and Black (also 1993) with Rachel Weisz and made his film debut in Bill Forsyth's Being Human (1994). For his role in the thriller Shallow Grave (also 1994), he won an Empire Award. The film was his first collaboration with director Danny Boyle. He had a major role in the 1996 Channel 4 comedy-drama film Brassed Off, written and directed by Mark Herman. His international breakthrough followed with the role of heroin addict Mark Renton in Boyle's Trainspotting (1996), an adaptation of Irvine Welsh's novel of the same name. In 1998, McGregor played the male romantic lead role in the British film Little Voice, and rockstar Curt Wild in the film Velvet Goldmine directed by Todd Haynes. He was cast as the young Obi-Wan Kenobi in the Star Wars prequel trilogy, released between 1999 and 2005. Kenobi was originally played by Alec Guinness in the first Star Wars trilogy. McGregor's uncle, Denis Lawson, had played Wedge Antilles in the original trilogy. While the prequels received mixed reviews, McGregor's performance was well received. McGregor said making the prequels was difficult, as he had to act mostly against green screens and the dialogue was "not exactly Shakespeare". He also stated that the negative reaction to the films had been difficult.
Freshly made, raw tempeh remains edible for a few days at room temperature. It is neither acidic nor does it contain significant amounts of alcohol. It, however, shows greater resistance to spoilage processes such as lipid peroxidation than unfermented soybeans due to its antioxidant contents. Cooking methods such as tempe kering, the deep-fried and seasoned bits of tempeh allows Tempeh to last for a month or more and still be good to consume, if cooked correctly and stored properly in an air-tight jar. The deep-frying process removes the moisture, preventing further fermentation and deterioration, thus prolonging its shelf life.
Sources: en.wikipedia.org
For his work, Alexander Bogomolets received in 1941 the Stalin Prize, which for Soviet scientists of those years was even more important than the Nobel Prize. 1938 The first specialized society dedicated to the study of aging. It was formed in Germany, Leipzig and was named the German Society for Aging Research (German: Deutsche Gesellschaft für Altersforschung, soon renamed to Deutsche Gesellschaft für Alternsforschung). The founder is Max Bürger. He also established the specialized journal Zeitschrift für Altersforschung – it is already the third such journal in the world after the previously mentioned Japanese and Romanian journals. 1938 The world's first scientific conference on aging and longevity in 1938 in Kiev, that was convened by Alexander Bogomolets. 1939 In the United Kingdom, the British Society for Research on Ageing is formed. The founder is Vladimir Korenchevsky who emigrated there from the former Russian Empire.
Among the notable guests on Galloway's RT programmes have been Gilad Atzmon, and Shlomo Sand. In the register of members' financial interests published at the end of January 2015, Galloway disclosed that he had earned £293,450 from his television broadcasting in the previous year and had received almost £70,000 in travelling expenses and hotel stays. For the period November 2013 to February 2015, Galloway was paid £100,000 for his appearances on RT, the highest payment to any British politician working for the channel. In 2016, Galloway presented a documentary film, The Killing$ of Tony Blair.
=== Types of vitamin A === It is "largely impossible" for provitamin carotenoids, such as beta-carotene, to cause toxicity, as their conversion to retinol is highly regulated. No vitamin A toxicity has ever been reported from ingestion of excessive amounts. Overconsumption of beta-carotene can only cause carotenosis, a harmless and reversible cosmetic condition in which the skin turns orange. Preformed vitamin A absorption and storage in the liver occur very efficiently until a pathologic condition develops. When ingested, 70–90% of preformed vitamin A is absorbed.
B chromosome Any supernumerary nuclear DNA molecule which is not a duplicate of nor homologous to any of the standard complement of normal "A" chromosomes comprising a genome. Typically very small and devoid of structural genes, B chromosomes are by definition not necessary for life. Though they occur naturally in many eukaryotic species, they are not stably inherited and thus vary widely in copy number even between closely related individuals.
Within the Communist Party of Great Britain, dissent that began with the repudiation of Stalin by John Saville and E. P. Thompson, influential historians and members of the Communist Party Historians Group, culminated in a loss of thousands of party members as events unfolded in Hungary. Peter Fryer, correspondent for the party newspaper The Daily Worker, reported on the violent suppression of the uprising, but his dispatches were heavily censored. Fryer resigned from the paper upon his return and was later expelled from the party. In France, moderates such as historian Emmanuel Le Roy Ladurie resigned, questioning the policy of supporting Soviet actions by the French Communist Party. The French anarchist philosopher and writer Albert Camus wrote an open letter titled The Blood of the Hungarians, criticising the West's lack of action. Jean-Paul Sartre, still a determined party member, criticised the Soviets. In the post-war years, socialism became increasingly influential throughout the so-called Third World after decolonisation. During India's freedom movement and fight for independence, many figures in the leftist faction of the Indian National Congress organised themselves as the Congress Socialist Party. Their politics and those of the early and intermediate periods of Jayaprakash Narayan's career combined a commitment to the socialist transformation of society with a principled opposition to the one-party authoritarianism they perceived in the Stalinist model. In Africa, many independence movements (e.g.
Sources: en.wikipedia.org
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.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
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.