nasal drops 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.
Updated 2026-04-23. Numbers and descriptions here follow the published literature rather than marketing material.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
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.
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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.
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.
== Nomenclature == Usually, a "phenyl group" is synonymous with C6H5− and is represented by the symbol Ph (archaically, Φ), or Ø. Benzene is sometimes denoted as PhH. Phenyl groups are generally attached to other atoms or groups. For example, triphenylmethane (Ph3CH) has three phenyl groups attached to the same carbon center. Many or even most phenyl compounds are not described with the term "phenyl". For example, the chloro derivative C6H5Cl is normally called chlorobenzene, although it could be called phenyl chloride. In special (and rare) cases, isolated phenyl groups are detected: the phenyl anion (C6H−5), the phenyl cation (C6H+5), and the phenyl radical (C6H•5). Although Ph and phenyl uniquely denote C6H5−, substituted derivatives also are described using the phenyl terminology. For example, C6H4NO2− is nitrophenyl, and C6F5− is pentafluorophenyl. Monosubstituted phenyl groups (that is, disubstituted benzenes) are associated with electrophilic aromatic substitution reactions and the products follow the arene substitution pattern. So, a given substituted phenyl compound has three isomers, ortho (1,2-disubstitution), meta (1,3-disubstitution) and para (1,4-disubstitution). A disubstituted phenyl compound (trisubstituted benzene) may be, for example, 1,3,5-trisubstituted or 1,2,3-trisubstituted. Higher degrees of substitution, of which the pentafluorophenyl group is an example, exist and are named according to IUPAC nomenclature.
Feminist Anne Koedt argued that because men "have orgasms essentially by friction with the vagina" and not the clitoral area, this is why women's biology had not been properly analyzed. "Today, with extensive knowledge of anatomy, with [C. Lombard Kelly], Kinsey, and Masters and Johnson, to mention just a few sources, there is no ignorance on the subject [of the female orgasm]", she stated in her 1970 article The Myth of the Vaginal Orgasm. She added, "There are, however, social reasons why this knowledge has not been popularized. We are living in a male society which has not sought change in women's role". Supporting an anatomical relationship between the clitoris and vagina is a study published in 2005, which investigated the size of the clitoris; Australian urologist Helen O'Connell, described as having initiated discourse among mainstream medical professionals to refocus on and redefine the clitoris, noted a direct relationship between the legs or roots of the clitoris and the erectile tissue of the bulbs and corpora, and the distal urethra and vagina while using magnetic resonance imaging (MRI) technology. While some studies, using ultrasound, have found physiological evidence of the G-spot in women who report having orgasms during vaginal intercourse, O'Connell argues that this interconnected relationship is the physiological explanation for the conjectured G-spot and experience of vaginal orgasms, taking into account the stimulation of the internal parts of the clitoris during vaginal penetration. "The vaginal wall is, in fact, the clitoris", she said.
==== Charge-transfer dissociation ==== Reaction between positively charged peptides and cationic reagents, also known as charge transfer dissociation (CTD), has recently been demonstrated as an alternative high-energy fragmentation pathway for low-charge state (1+ or 2+) peptides. The proposed mechanism of CTD using helium cations as the reagent is:
Sources: en.wikipedia.org
=== Kyrgyzstan === Kyrgyzstan has a similar HIV/AIDS problem as Ukraine and to try and combat this, started a trial methadone program within prisons. The first program started in a solo prison is 2002 and expanded to multiple in 2008. It is estimated that half of incarcerated individuals in Kyrgyzstan inject drugs and the use of unsterilized needles and transfer of HIV is higher in the prison setting. While the offering of methadone in prisons would help curb the spread of HIV/AIDS, the internal prison governance of inmates and their reliance on the drug trade is a hard barrier. Heroin being used as currency as well as methadone users being assigned to separate living quarters than non-users creates a social separation between users and non-users. These outcasting factors can make methadone treatment not worth it for some inmates. The number of eligible prisoners using methadone through a methadone program is estimated at only 7%.
== History == The efficacy of ceftolozane/tazobactam to treat complicated intra-abdominal infections (cIAI) in combination with metronidazole was established in a clinical trial with a total of 979 adults. Participants were randomly assigned to receive ceftolozane/tazobactam plus metronidazole or meropenem. Results showed ceftolozane/tazobactam plus metronidazole was effective for the treatment of cIAI. The efficacy of ceftolozane/tazobactam to treat complicated urinary tract infections (cUTI) was established in a clinical trial where 1,068 adults were randomly assigned to receive ceftolozane/tazobactam or levofloxacin. Ceftolozane/tazobactam demonstrated it was effective in treating cUTI. Ceftolozane/tazobactam was shown to be at least as effective as other antibiotics in curing infections in three main studies. One study involved 1,083 participants who mostly had kidney infection or in some cases a complicated urinary-tract infection. Ceftolozane/tazobactam successfully treated the infection in about 85% of the cases where it was given (288 of 340), compared with 75% (266 of 353) of those given another antibiotic called levofloxacin. The second study involved 993 participants with complicated intra-abdominal infections. Ceftolozane/tazobactam was compared with another antibiotic, meropenem. Both medicines cured 94% of participants (353 out of 375 given ceftolozane/tazobactam and 375 out of 399 given meropenem). The third study involved 726 participants who were using a ventilator and who had either hospital-acquired pneumonia or ventilator-associated pneumonia.
=== Eligibility === In the 11th version of the International Classification of Diseases (ICD-11), the diagnosis is known as gender incongruence. ICD-11 states that "Gender variant behaviour and preferences alone are not a basis for assigning the diagnosis." The US Diagnostic and Statistical Manual of Mental Disorders (DSM) names it gender dysphoria (in version 5). Some people who are validly diagnosed have no desire for all or some parts of hormone replacement therapy, or gender affirming surgery, and/or are not appropriate candidates for such treatment. The general standards for diagnosing, as well as treating distress caused by gender incongruence or gender dysphoria are outlined in the WPATH Standards of Care for the Health of Transgender and Gender Diverse People. As of February 2023, the most recent version of the standards is Version 8, called SOC8 in short. According to the standards of care, "Gender Dysphoria describes a state of distress or discomfort that may be experienced because a person's gender identity differs from that which is physically and/or socially attributed to their sex assigned at birth... Not all transgender and gender diverse people experience gender dysphoria." Gender nonconformity is not the same as gender dysphoria; nonconformity, according to the standards of care, is not a pathology and does not require medical treatment. The WPATH Standards of Care in the latest version 8 from February 2023, follow an informed consent model, which is the default approach that most medical professionals administering gender-affirming care follow today.
==== Learning ==== Since the seminal studies of Charles Darwin on earthworm intelligence much work has been done on the capacity of earthworms, in particular members of the widespread Lumbricus terrestris, to learn, although some doubts were raised about the use of T-maze experiments for demonstrating learning by earthworms.
Sources: en.wikipedia.org
=== Electrical conductivity and electrolysis === Pure water has a low electrical conductivity, which increases with the dissolution of a small amount of ionic material such as common salt. Liquid water can be split into the elements hydrogen and oxygen by passing an electric current through it—a process called electrolysis. The decomposition requires more energy input than the heat released by the inverse process (285.8 kJ/mol, or 15.9 MJ/kg).
=== Other functions === Knockout and molecular studies in mice suggest that this kinase is important for regulating behavioural response to morphine and alcohol. It also plays a role lipopolysaccharide (LPS)-mediated signaling in activated macrophages and in controlling anxiety-like behavior.
transposase Any of a class of self-acting enzymes capable of binding to the flanking sequences of the transposable element which encodes them and catalyzing its movement to another part of the genome, typically by an excision/insertion mechanism or a replicative mechanism, in a process known as transposition.
=== 2021: Olympic gold, second ATP Finals title === Zverev began his season in February with the ATP Cup, where he represented Germany with Jan-Lennard Struff, Kevin Krawietz and Andreas Mies to reach the semi-finals. In his first Grand Slam tournament appearance at the 2021 Australian Open, he defeated Marcos Giron, Maxime Cressy, Adrian Mannarino and Dušan Lajović. His run ended in the quarterfinals, where he lost to the eventual champion and world No. 1 Novak Djokovic. In March his first tournament was in Rotterdam, where he lost in the first round to Kazakh Alexander Bublik. He continued his performances in Acapulco, where he won his 14th ATP title by defeating Stefanos Tsitsipas in the final. At the tournament in Miami, he lost in the second round to Finland's Emil Ruusuvuori. At his first tournament in 2021 on clay in Monte Carlo, Zverev finished in the third round, losing to David Goffin. In Munich, he reached the quarterfinals, losing to the 107th ranked tennis player in the world, Ilya Ivashka. At the Madrid Open, Zverev defeated Rafael Nadal, Dominic Thiem, and Matteo Berrettini en route to his fourth Masters 1000 title and 15th career title. At the same tournament, he also reached his first semifinal in doubles at a Masters 1000, partnering with compatriot Tim Pütz, but withdrew from the match. He reached the quarterfinals of the Masters 1000 in Rome, losing to eventual tournament winner Rafael Nadal. In his second Grand Slam tournament of the year – in Paris, where he was seeded No.
The Russian Empire organized its Cossacks into several voiskos (hosts), which lived along the Russian border and internal borders between Russian and non-Russian peoples. Each host originally had its own leadership, ranks, regalia, and uniforms. By the late 19th century, ranks were standardized following the example of the Imperial Russian Army. The ranks and insignia were kept after the 1988 law allowing the hosts to reform, and the 2005 law legally recognizing the hosts as a combat service. They are given below as per all military tickets that are standard for the Russian Army.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
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.