Semax 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 2025-11-20. Numbers and descriptions here follow the published literature rather than marketing material.
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 a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
| 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 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.
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.
Like autistic savants, some hyperthymesiacs develop an obsessive fascination with dates. Jill Price, the first documented case, differed notably from mnemonist Solomon Shereshevsky, described by psychologist Alexander Luria. Shereshevsky could deliberately memorise vast amounts of information, whereas Price could recall only autobiographical events and generally performed poorly at memorisation tasks. Hyperthymestic individuals may even have below-average memory for arbitrary information. Another parallel drawn between Price and Shereshevsky is the role of synesthesia. Shereshevsky exemplified time-space synesthesia, and some researchers suggest superior autobiographical memory may be linked to this phenomenon.
1993/931) Friendly Societies Act 1992 (Transitional and Consequential Provisions and Savings) Regulations 1993 (S.I. 1993/932) Finance Act 1991, section 58, (Commencement No. 3) Regulations 1993 (S.I. 1993/933) Legal Aid in Criminal and Care Proceedings (Costs) (Amendment) Regulations 1993 (S.I. 1993/934) Housing Benefit and Community Charge Benefit (Subsidy) (No. 2) Order 1993 (S.I. 1993/935) Certification Officer (Amendment of Fees) Regulations 1993 (S.I. 1993/936) Further Education (Exclusion of Land from Transfer) (No. 2) Order 1993 (S.I. 1993/937) Land Registry Trading Fund Order 1993 (S.I. 1993/938) Land Registration (Determination of Costs) Order 1993 (S.I. 1993/939) Local Government Administration (Matters Subject to Investigation) Order 1993 (S.I. 1993/940) Local Elections (Variation of Limits of Candidates' Election Expenses) (Northern Ireland) Order 1993 (S.I. 1993/941) Copyright (Application to Other Countries) Order 1993 (S.I. 1993/942) Performances (Reciprocal Protection) (Convention Countries) Order 1993 (S.I. 1993/943) European Communities (Definition of Treaties) (International Railway Tariffs Agreements) Order 1993 (S.I. 1993/944) Insurance Companies (Accounts and Statements) (Amendment) Regulations 1993 (S.I. 1993/946) Patents (Supplementary Protection Certificate for Medicinal Products) (Amendment) Rules 1993 (S.I. 1993/947) Chessington Computer Centre Trading Fund Order 1993 (S.I. 1993/948) Income Tax (Interest Relief) (Qualifying Lenders) Order 1993 (S.I. 1993/949) Capital Gains Tax (Gilt-edged Securities) Order 1993 (S.I.
It has been suggested that snakes evolved the mechanisms necessary for venom formation and delivery sometime during the Miocene epoch. During the mid-Tertiary, most snakes were large ambush predators belonging to the superfamily Henophidia, which use constriction to kill their prey. As open grasslands replaced forested areas in parts of the world, some snake families evolved to become smaller and thus more agile. However, subduing and killing prey became more difficult for the smaller snakes, leading to the evolution of snake venom. The most likely hypothesis holds that venom glands evolved from specialized salivary glands. The venom itself evolved through the process of natural selection; it retained and emphasized the qualities that made it useful in killing or subduing prey. Today we can find various snake species in stages of this hypothesized development. There are the highly efficient envenoming machines - like the rattlesnakes - with large capacity venom storage, hollow fangs that swing into position immediately before the snake bites, and spare fangs ready to replace those damaged or lost. Other research on Toxicofera, a hypothetical clade thought to be ancestral to most living reptiles, suggests an earlier time frame for the evolution of snake venom, possibly to the order of tens of millions of years, during the Late Cretaceous. Snake venom is produced in modified parotid glands normally responsible for secreting saliva. It is stored in structures called alveoli behind the animal's eyes and ejected voluntarily through its hollow tubular fangs.
Sources: en.wikipedia.org
Birds have featured in culture and art since prehistoric times, when they were represented in early cave painting and carvings. Some birds have been perceived as monsters, including the mythological Roc and the Māori's legendary Pouākai, a giant bird capable of snatching humans. Birds were later used as symbols of power, as in the magnificent Peacock Throne of the Mughal and Persian emperors. With the advent of scientific interest in birds, many paintings of birds were commissioned for books. Among the most famous of these bird artists was John James Audubon, whose paintings of North American birds were a great commercial success in Europe and who later lent his name to the National Audubon Society. Birds are also important figures in poetry; for example, Homer incorporated nightingales into his Odyssey, and Catullus used a sparrow as an erotic symbol in his Catullus 2. The relationship between an albatross and a sailor is the central theme of Samuel Taylor Coleridge's The Rime of the Ancient Mariner, which led to the use of the term as a metaphor for a 'burden'. Other English metaphors derive from birds; vulture funds and vulture investors, for instance, take their name from the scavenging vulture. Aircraft, particularly military aircraft, are frequently named after birds. The predatory nature of raptors make them popular choices for fighter aircraft such as the F-16 Fighting Falcon and the Harrier Jump Jet, while the names of seabirds may be chosen for aircraft primarily used by naval forces such as the HU-16 Albatross and the V-22 Osprey.
It is a situation similar to lipocalins (from Greek lipos=fat and Greek kalyx=cup), where the name designates a superfamily of widely distributed and heterogenous proteins, which transport small hydrophobic molecules including steroids and lipids. However, in contrast to lipocalins, the “CSP” family refers to homogenous evolutionary-well conserved proteins with characteristic sequence (4 cysteines), tissue profiling (ubiquitously expressed), and rather highly diverse binding properties (not only to long fatty acids (FAs) and straight lipid chains, but also to cyclic compounds such as cinnamaldehyde) [34]. Therefore, it is rather difficult to name groups and sub-groups within the CSP family, although numerous CSP proteins are mainly produced in the gut and the fat body that are considered as the insect body’s principle storage organs for energy in the forms of FAs and lipids, which are mobilized through lipolysis process to provide fuel to other organs to develop, regenerate or grow and/or to respond to an infectious agent [4, 14, 50]. In moths, specific lipid chains are mobilized for pheromone synthesis [9-14].
==== Relationship with Rod Blagojevich ==== Illinois Governor Rod Blagojevich appointed Pritzker to chair the Illinois Human Rights Commission in 2003. He held that position until 2006. After Pritzker left the chairmanship, Blagojevich appointed former White House counsel and federal judge Abner J. Mikva to succeed him. A controversial phone call between Pritzker and Blagojevich, which was recorded on an FBI wiretap, took place during the 2008 corruption scandal. The Chicago Tribune described Pritzker at the time as a "businessman with political ambitions". On the call, Blagojevich asked Pritzker whether he would like to be appointed state treasurer, to which Pritzker responded, "Yeah, that's the one I would want." He and Blagojevich also discussed filling Barack Obama's U.S. Senate seat, with Pritzker saying that appointing then-Secretary of State Jesse White would "cover you on the African-American thing" and that he was the "least offensive" Black candidate. After the Tribune released the recording during the 2018 gubernatorial election, Governor Bruce Rauner and Pritzker's Democratic primary opponents criticized his conduct. Pritzker responded: "I've not been accused of any wrongdoing.
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.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.