The short version of synthetic heptapeptide 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.
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.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
His dialogue sounds composed entirely of sentences memorized from tourist phrase books." Mark Olsen of the Los Angeles Times wrote that "All of the film's purposeful weirdness is conveyed with an unaffected simplicity that recalls the dead-aim haphazard compositions of photographer William Eggleston", concluding that, "as a film, it's pure and singular, but it's not quite fully formed enough to be what one could call truly visionary." A. O. Scott of The New York Times wrote that the film "at times seems as much an exercise in perversity as an examination of it", and that "The static wide-screen compositions are beautiful and strange, with the heads and limbs of the characters frequently cropped. The light is gauzy and diffuse, helping to produce an atmosphere that is insistently and not always unpleasantly dreamlike. You might think of paintings by Balthus or maybe Alex Katz, though the implied stories in those pictures are more genuinely evocative and haunting than the actual narrative of Dogtooth." Several reviewers, such as Harkness and Bradshaw, made comparisons to the 2008 Fritzl case, although they noted that the screenplay was written before the case emerged. Scott, like Ebert, made references to homeschooling. The film's larger meaning eluded easy expression. Scott called the film "a conversation piece. Though the conversation may... be more along the lines of: 'What was that?' 'I don't know. Weird.' 'Yeah.' [shudder].
Halliwell was awarded the Public Administration Medal (Silver) in 2010 by the President of Singapore for contributions to Singapore and awarded the President's Science and Technology Medal (2013) by the President of Singapore "for distinguished sustained and exceptional contributions to Singapore's Science and Engineering landscape". Halliwell was conferred the Outstanding Service Award at the NUS University Awards on 8 September 2023. In 2008, Halliwell was awarded the "Lifetime Achievement Award" by the Society for Free Radical Biology and Medicine in the US for overall sustained excellence in the field. He was described as a "Research Pioneer" by the journal Antioxidants & Redox Signaling in 2011. Same year, he was also awarded the Ken Bowman Research Award for outstanding achievements in the field of cardiovascular research from the Institute of Cardiovascular Sciences (Canada) and NUS University Award – Outstanding Researcher Award. He was elected a fellow of the American Association for the Advancement of Science in 2012. Halliwell was awarded a Doctor of Science honoris causa by King's College London in 2018. He was again identified as a "Highly Cited Scientist" for cross-disciplinary work by Clarivate Analytics in 2018. He was honoured as a Citation Laureate (2021) for "pioneering research in free-radical chemistry including the role of free radicals and antioxidants in human disease".
== Safety risk == HCPs in biopharmaceutical products pose a potential safety risk to humans by introducing foreign proteins and biomolecules to the human immune system. Since common host cells used to produce biopharmaceutical drugs are E. coli, yeast, mouse myeloma cell line (NS0) and Chinese hamster ovary (CHO), the resultant HCPs are genetically different to what the human body recognizes. As a consequence of this, the presence of HCPs in humans can activate an immune response, which can lead to possibly severe health concerns. There is a correlation between the amount of foreign antigens (HPCs) in our body and the level of immune response our body produces. The more HCPs present in a drug, the higher the immune response that will be activated. Several studies have linked a reduction in HCPs to a decline in specific inflammatory cytokines. Other HCPs may be very similar to a human protein and may induce an immune response with cross reactivity against the human protein or the drug substance protein. The exact consequences of HCPs for an individual patient is uncertain and difficult to determine with the current analytical methods used in biopharmaceutical production and analysis.
== A == ABC-Transporter Genes - abl gene - acetic acid - acetyl CoA - acetylcholine - acetylcysteine - acid - acidic fibroblast growth factor - acrosin - actin - action potential - activation energy - active site - active transport - adenosine - adenosine diphosphate (ADP) - adenosine monophosphate (AMP) - adenosine triphosphate (ATP) - adenovirus - adrenergic receptor - adrenodoxin - aequorin - aerobic respiration - agonist - alanine - albumin - alcohol - alcoholic fermentation - alicyclic compound - aliphatic compound - alkali - allosteric site - allostery - allotrope - allotropy - alpha adrenergic receptor - alpha helix - alpha-1 adrenergic receptor - alpha-2 adrenergic receptor - alpha-beta T-cell antigen receptor - alpha-fetoprotein - alpha-globulin - alpha-macroglobulin - alpha-MSH - Ames test - amide - amine - amino - amino acid - amino acid receptor - amino acid sequence - amino acid sequence homology - aminobutyric acid - ammonia - AMPA receptor - amyloid - anabolism - anaerobic respiration - analytical chemistry - androgen receptor - angiotensin - angiotensin II - angiotensin receptor - ankyrin - annexin II - antibiotic - antibody - apoenzyme - apolipoprotein - apoptosis - aquaporin - archaea - arginine - argipressin - aromatic amine - aromatic compound - arrestin - Arrhenius equation - aryl hydrocarbon receptor - asparagine - aspartic acid - atom - atomic absorption spectroscopy - atomic mass - atomic nucleus - atomic number - atomic orbital - atomic radius - Atomic weight - ATP synthase - ATPase - atrial natriuretic factor - atrial natriuretic factor receptor - Avogadro constant - axon
Sources: en.wikipedia.org
== Research == Nefazodone was under development for the treatment of panic disorder, and reached phase 3 clinical trials for this indication, but development was discontinued in 2004. The use of nefazodone to prevent migraine has been studied, due to its antagonism of the serotonin 5-HT2A and 5-HT2C receptors.
== Mechanism == Antivenoms act by binding to and neutralizing venoms. The principle of antivenom is based on that of vaccines, developed by Edward Jenner; however, instead of inducing immunity in the person directly, it is induced in a host animal and the hyperimmunized serum is transfused into the person. The host animals may include horses, donkeys, goats, sheep, rabbits, chickens, llamas, and camels. In addition, opossums are being studied for antivenom production, as unique opossum blood proteins such as lethal toxin neutralizing factor can neutralize snake venoms. Antivenoms for medical use are often preserved as freeze-dried ampoules, but some are available only in liquid form and must be kept refrigerated. They are not immediately inactivated by heat, however, so a minor gap in the cold chain is not disastrous.
=== Ontologies and data integration === Biological ontologies are directed acyclic graphs of controlled vocabularies. They create categories for biological concepts and descriptions so they can be easily analyzed with computers. When categorised in this way, it is possible to gain added value from holistic and integrated analysis. The OBO Foundry was an effort to standardise certain ontologies. One of the most widespread is the Gene ontology which describes gene function. There are also ontologies which describe phenotypes.
Various ecosystems are represented in the Beach Gardens and the Hauser Park (caves). Finally, the Plateau of Dollemard was classified as a "Sensitive Natural Area" of the department in 2001 to protect its landscape and ecosystems on the cliff. The streets are lined with 13,000 trees of 150 different varieties.
== External links == Histology image: 13906loa – Histology Learning System at Boston University - "Respiratory System: lung (human), alveolar macrophages" Histology at KUMC resp-resp16 "Alveoli" Slide at ufl.edu
Sources: en.wikipedia.org
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.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.