If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
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。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
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。
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.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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.
=== Dimension-5 proton decay operators === Also dimension-5 operators are possible in supersymmetric models, even after the introduction of R-parity, for instance where a heavy color-triplet Higgs exchange (represented by the internal Higgsino lines
=== Transdermal administration === Transdermal estradiol is available in the forms of patches, gels, emulsions, and sprays. In the case of gels, emulsions, and sprays, the route is sometimes referred to as topical rather than as transdermal. Topical administration can also refer to vaginal administration of gels and creams however. Estradiol has moderate skin permeability, which is based on the lipophilicity and hydrophilicity of a compound. In general, the more polar groups, such as hydroxyl groups, that are present in a steroid, and hence the more hydrophilic and less lipophilic it is, the lower its skin permeability. For this reason, estrone and progesterone have higher skin permeability, while estriol and cortisol have lower skin permeability. The transdermal bioavailability of estradiol in an alcohol solution is approximately 10%. Transdermal estradiol reservoir patches have been reported to have a bioavailability of 3 to 5%. Estradiol is a highly potent compound and circulates at picomolar concentrations (pg/mL), which makes it ideal for transdermal application as only small amounts of substance need to be delivered across the skin. Conversely, progesterone, which circulates at levels in the nanomolar range and requires a far higher quantity of substance for biological effect, is not well-suited for transdermal delivery.
On April 2, 2011, a month and a half before the municipal elections and autonomous communities elections were held, Zapatero, under pressure from his own party, announced that he would not be the head of the list in the next general elections. However, Zapatero's resignation did not prevent the Socialist landslide in the municipal and autonomic elections, as the PSOE was 10 points behind the People's Party. Shortly afterwards the PSOE named Alfredo Pérez Rubalcaba as its new candidate for the presidency of government. The Sunday before the celebration of the municipal and autonomic elections, May 15, 2011, there were demonstrations of "outraged" ones, mostly young people, in the main Spanish cities called by the grassroots organization "¡Democracia Real YA!". The next day, a group of them decided to camp in the Puerta del Sol in Madrid and the eviction by the police only increased the number of campers who ended up occupying the entire square and getting great national and international media coverage, in addition to their example quickly spread to the squares of many cities. There they remained for several weeks. One of the most repeated slogans in the assemblies they held was "¡No nos representan!" ("They don't represent us!") in reference to the big political parties. Thus was born what would become known as the 15-M movement.
brevicaule complex. DNA analysis however shows that more than 99% of all current varieties of potatoes are direct descendants of a subspecies that once grew in the lowlands of south-central Chile. Most modern potatoes grown in North America arrived through European settlement and not independently from the South American sources. At least one wild potato species, Solanum fendleri, occurs in North America; it is used in breeding for resistance to a nematode species that attacks cultivated potatoes. A secondary center of genetic variability of the potato is Mexico, where important wild species used extensively in modern breeding are found, such as the hexaploid S. demissum, used as a source of resistance to the devastating late blight disease (Phytophthora infestans). Another relative native to this region, Solanum bulbocastanum, has been used to genetically engineer the potato to resist potato blight. Many such wild relatives are useful for breeding resistance to P. infestans. Little of the diversity found in Solanum ancestral and wild relatives is found outside the original South American range. This makes these South American species highly valuable in breeding. The importance of the potato to humanity is recognised in the United Nations International Day of Potato, to be celebrated on 30 May each year, starting in 2024.
Sources: en.wikipedia.org
==== 2025 CDC leadership dispute ==== On May 14, 2025, Robert F. Kennedy Jr. stated that lawyer Matthew Buzzelli is acting CDC director, though the CDC web site did not list that name. Susan Monarez was confirmed as CDC head on July 31, 2025, but on August 27, she was fired. Monarez disputed the legality of the firing, as it had not been carried out by the president, and it had been falsely reported that she had resigned. The president later officially carried out the firing. The firing was due to her refusing to rubber stamp what were expected to be unscientific recommendations from the senior staff vaccine experts, as well as refusing to fire them. The dispute began over demands from Kennedy and his top staff for changing the recommendation for COVID vaccine to persons with higher-risk conditions and senior citizens only. The official recommendation also affects insurance coverage and whether vaccines are available in pharmacies. Senator Bill Cassidy called for the next meeting of the Advisory Committee on Immunization Practices to be postponed. He said, "Serious allegations have been made about the meeting agenda, membership, and lack of scientific process being followed for the now announced September ACIP meeting. These decisions directly impact children's health and the meeting should not occur until significant oversight has been conducted." The next day, the Trump administration announced the selection of Deputy Secretary of Health and Human Services Jim O'Neill as a replacement.
== Genes == Fibrinogen is made and secreted into the blood primarily by liver hepatocyte cells. Endothelium cells are also reported to make small amounts of fibrinogen, but this fibrinogen has not been fully characterized; blood platelets and their precursors, bone marrow megakaryocytes, while once thought to make fibrinogen, are now known to take up and store but not make the glycoprotein. The final secreted, hepatocyte-derived glycoprotein is composed of two trimers, with each trimer composed of three different polypeptide chains, the fibrinogen alpha chain (also termed the Aα or α chain) encoded by the FGA gene, the fibrinogen beta chain (also termed the Bβ or β chain) encoded by the FGB gene, and the fibrinogen gamma chain (also termed the γ chain) encoded by the FGG gene. All three genes are located on the long or "q" arm of human chromosome 4 (at positions 4q31.3, 4q31.3, and 4q32.1, respectively).
CD38 (cluster of differentiation 38), also known as cyclic ADP ribose hydrolase, is a glycoprotein found on the surface of many immune cells (white blood cells), including CD4+, CD8+, B lymphocytes and natural killer cells. CD38 also functions in cell adhesion, signal transduction and calcium signaling. In humans, the CD38 protein is encoded by the CD38 gene which is located on chromosome 4. CD38 is a paralog of CD157, which is also located on chromosome 4 (4p15) in humans.
Sources: en.wikipedia.org
=== Differential diagnoses === The muscle weakness that worsens with activity (abnormal muscle fatigue) in myasthenia gravis is a symptom shared by other neuromuscular diseases. Most of the metabolic myopathies, such as McArdle disease (GSD-V), have abnormal muscle fatigue rather than fixed muscle weakness. Also, like myasthenia gravis, exercise intolerance in McArdle disease improves with regular physical activity (performed safely using activity adaptations such as getting into second wind, the "30 for 80 rule," and "six second rule"). A small minority of people with McArdle disease also have the comorbidity of ptosis (drooping upper eyelid). Late-onset GSD-II (Pompe disease) and GSD-XV also have muscle weakness or fatigue with comorbidities of ptosis and ophthalmoplegia; as do many of the mitochondrial myopathies. Other diseases that involve abnormal muscle fatigue (which may be described as exercise-induced muscle weakness, reversible muscle weakness, or muscle weakness that improves with rest) include: endocrine myopathies (such as Hoffman syndrome), Tubular aggregate myopathy (TAM), ischemia (such as intermittent claudication, popliteal artery entrapment syndrome, and chronic venous insufficiency), and poor diet or malabsorption diseases that lead to vitamin D deficiency (osteomalic myopathy). Although limb-girdle muscular dystrophies (LGMDs) involve fixed muscle weakness, LGMDR8 also involves muscle fatigue; as do some limb-girdle muscular dystrophy-dystroglycanopathies such as MDDGC3 (a.k.a. LGMDR15 and LGMD2O).
1993/851) Value Added Tax (General) (Amendment) (No.3) Regulations 1993 (S.I. 1993/856) Social Security (Industrial Injuries and Adjudication) Regulations 1993 (S.I. 1993/861) Social Security (Industrial Injuries) (Prescribed Diseases) Amendment Regulations 1993 (S.I. 1993/862) Official Secrets (Prohibited Places) (Amendment) Order 1993 S.I. 1993/863) Devon and Cornwall Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/864) West Mercia Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/865) Sussex Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/866) Avon and Somerset Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/867) Thames Valley Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/868) South Wales Police (Amalgamation) (Amendment) Order 1993 (S.I. 1993/869) Education (Designated Institutions in Further and Higher Education) (Interpretation) (Amendment) Order 1993 (S.I. 1993/870) A13 Trunk Road (Newham, Barking and Dagenham, and Havering) (Speed Limits) Order 1988 (Variation) Order 1993 (S.I. 1993/871) Western Isles Islands Council (Lochmaddy) Water Order 1993 (S.I. 1993/872) Oil Related and Petrochemical Plants (Rateable Values) (Scotland) Order 1993 (S.I. 1993/873) Electricity Generators (Rateable Values) (Scotland) Order 1993 (S.I. 1993/874) Scottish Hydro-Electric plc. (Rateable Values) (Scotland) Order 1993 (S.I. 1993/875) Industrial and Freight Transport (Rateable Values) (Scotland) Order 1993 (S.I. 1993/876) Scottish Nuclear Limited (Rateable Values) (Scotland) Order 1993 (S.I. 1993/877) Scottish Power plc.
Clinicians use drug detoxification to reduce or relieve withdrawal symptoms while helping an addicted person adjust to living without drug use. Drug detoxification does not aim to treat addiction but rather represents an early step within long-term treatment. Detoxification may be achieved drug-free or may use medications as an aspect of treatment. Often drug detoxification and treatment will occur in a community program that lasts several months and takes place in a residential setting rather than in a medical center. Drug detoxification varies depending on the location of treatment, but most detox centers provide treatment to avoid the symptoms of physical withdrawal from alcohol and from other drugs. Most also incorporate counseling and therapy during detox to help with the consequences of withdrawal.
Cocaine should not be used in individuals with a known allergy or hypersensitivity to the drug or any components of its topical formulation. It is also contraindicated in elderly patients and those with a history of hypertension or cardiovascular disease.
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.