The short version of ACTH analog fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-07 and is reviewed periodically as new material appears.
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 compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
A Dyson tree is a hypothetical genetically engineered plant (perhaps resembling a tree) capable of growing inside a comet, suggested by the physicist Freeman Dyson. Plants may be able to produce a breathable atmosphere within the hollow spaces of the comet (or maybe even within the plants themselves), utilising solar energy for photosynthesis and cometary materials for nutrients, thus providing self-sustaining habitats for humanity in the outer solar system analogous to a greenhouse in space, a shell grown by a mollusc or the actions of thermogenic plants, such as the skunk cabbage or the voodoo lily. A Dyson tree might consist of a few main trunk structures growing out from a comet nucleus, branching into limbs and foliage that intertwine, forming a spherical structure possibly dozens of kilometers across.
=== Gray baby syndrome === Intravenous chloramphenicol use has been associated with the so-called gray baby syndrome. This phenomenon occurs in newborn infants because they do not yet have fully functional liver enzymes (i.e. UDP-glucuronyl transferase), so chloramphenicol remains unmetabolized in the body. This causes several adverse effects, including hypotension and cyanosis. The condition can be prevented by using the drug at the recommended doses, and monitoring blood levels.
=== Coatings === Castor oil is used as a biobased polyol in the polyurethane industry. The average functionality (number of hydroxyl groups per triglyceride molecule) of castor oil is 2.7, so it is widely used as a rigid polyol and in coatings. One particular use is in a polyurethane concrete where a castor-oil emulsion is reacted with an isocyanate (usually polymeric methylene diphenyl diisocyanate) and a cement and construction aggregate. This is applied fairly thickly as a slurry, which is self-levelling. This base is usually further coated with other systems to build a resilient floor. Castor oil is not a drying oil, meaning that it has a low reactivity with air compared with oils such as linseed oil and tung oil. However, dehydration of castor oil yields linoleic acids, which do have drying properties. In this process, the OH group on the ricinoleic acid along with a hydrogen from the next carbon atom are removed, forming a double bond which then has oxidative cross-linking properties and yields the drying oil. It is considered a vital raw material.
== Evolution == Mycorrhizal symbioses are ubiquitous in terrestrial ecosystems, and it is possible that these associations helped to facilitate land colonization by plants. There is paleobiological and molecular evidence that arbuscular mycorrhizas (AM) originated at least 460 million years ago. EcM plants and fungi exhibit a wide taxonomic distribution across all continents (apart from Antarctica), suggesting that the EcM symbiosis has ancient evolutionary roots. Pinaceae is the oldest extant plant family in which symbiosis with EcM fungi occurs, and fossils from this family date back to 156 million years ago. It has been proposed that habitat type and the distinct functions of different mycorrhizas help determine which type of symbiosis is predominant in a given area. In this theory, EcM symbioses evolved in ecosystems such as boreal forests that are relatively productive but in which nutrient cycling is still limiting. Ectomycorrhizas are intermediate in their ability to take up nutrients, being more efficient than arbuscular mycorrhizas and less so than ericoid mycorrhizas, making them useful in an intermediate nutrient situation.
Laidlaw left Valve in 2016. He said later that he had grown tired of the FPS genre and was "less interested in trying to solve the story problems inherent in a Half-Life style of narrative". In 2017, Laidlaw posted a short story titled "Epistle 3" on his website, describing it as "a snapshot of a dream I had many years ago". It features characters with names similar to Half-Life characters, such as Gertie Fremont for Gordon Freeman. Journalists interpreted the story as a synopsis of what could have been the plot for Episode Three, or for Borealis, another canceled project led by Laidlaw. Substituting the characters and locations with their Half-Life counterparts, "Epistle 3" has Gordon and Alyx travel to the Arctic to board the Borealis, a ship that travels erratically through time and space, where they confront alternative versions of themselves. They rig the Borealis to travel to the heart of the alien Combine empire and self-destruct. Before it explodes, the mysterious G-Man extracts Alyx and Gordon is rescued by the friendly Vortigaunt aliens. Walker denied that the story had been Valve's plan for Episode Three, and said that it was likely just one of many ideas by Laidlaw. In a 2023 interview, Laidlaw said it was not representative of Episode Three, as "all the real story development can only happen in the crucible of developing the game". He said he regretted publishing it, as it had created problems for his former colleagues at Valve, and that he had been "deranged" and "completely out of touch".
Sources: en.wikipedia.org
The main steroid hormones, testosterone, estradiol, and progesterone as well as prolactin play important physiological functions in puberty. The production of gonadal steroids in females starts with production of testosterone, which is typically quickly converted to estradiol inside the ovaries. However the rate of conversion from testosterone to estradiol (driven by FSH/LH balance) during early puberty is highly individual, resulting in very diverse development patterns of secondary sexual characteristics. Production of progesterone in the ovaries begins with the development of ovulatory cycles in females (during the lutheal phase of the cycle), before puberty low levels of progesterone are produced in the adrenal glands of both males and females. Estradiol levels rise earlier and reach higher levels in women than in men. While estradiol promotes growth of the breasts and uterus, it is also the principal hormone driving the pubertal growth spurt and epiphyseal maturation and closure.
=== Advantages and disadvantages === A fever response to an infectious disease is generally regarded as protective, whereas fever in non-infections may be maladaptive. Studies have not been consistent on whether treating fever generally worsens or improves mortality risk. Benefits or harms may depend on the type of infection, health status of the patient and other factors. Studies using warm-blooded vertebrates suggest that they recover more rapidly from infections or critical illness due to fever. In sepsis, fever is associated with reduced mortality.
Movement demands include strength, endurance and range of motion. Training oversights occurs when the body is overused. Internally, the joints, muscles, tendons, and ligaments can affect one's flexibility. As previously mentioned, each part of the body has its own limitations and combined, the range of motion can be affected. The mental attitude of the performer during the state of motion can also affect their range.
Biodistribution of 14C-labelled docetaxel in three patients showed the bulk of the drug to be metabolised and excreted in bile to the faeces. Of the radioactively labelled docetaxel administered, 80% was eliminated to the faeces with 5% in the urine over seven days, an indication that urinary excretion of docetaxel is minimal. Saliva contributed minimal excretion and no excretion was detected through pulmonary means. The terminal half-life of docetaxel was determined as approximately 86 hours, through prolonged plasma sampling, contrary to the clinically stated terminal half-life of 10–18 hours.
Sources: en.wikipedia.org
=== Budget authority versus outlays === The amount of budget authority and outlays for a fiscal year usually differ because the government can incur obligations for future years. This means that budget authority from a previous fiscal year can, in many cases, be used for expenditure of funds in future fiscal years; for example, a multi-year contract. Budget authority is the legal authority provided by federal law to enter into financial obligations that will result in immediate or future outlays involving federal government funds. Outlays refer to the issuance of checks, disbursement of cash or electronic transfer of funds made to liquidate a federal obligation and is usually synonymous with "expenditure" or "spending". The term "appropriations" refers to budget authority to incur obligations and to make payments from the Treasury for specified purposes. Some military and some housing programs have multi-year appropriations, in which their budget authority is specified for several coming fiscal years. In the congressional budgeting process, an "authorization" (technically the "authorization act") provides the legal authority for the executive branch to act, establishes an account which can receive money to implement the action, and sets a limit on how much money may be expended. However, this account remains empty until Congress approves an "appropriation", which requires the U.S. Treasury to provide funds (up to the limit provided for in the authorization). Congress is not required to appropriate as much money as is authorized.
=== Denaturing ribonucleases === 2-Mercaptoethanol is used in some RNA isolation procedures to eliminate ribonuclease released during cell lysis. Numerous disulfide bonds make ribonucleases very stable enzymes, so 2-mercaptoethanol is used to reduce these disulfide bonds and irreversibly denature the proteins. This prevents them from digesting the RNA during its extraction procedure.
To minimize this problem, commercial supplies of THF are often stabilized with butylated hydroxytoluene (BHT). Distillation of THF to dryness is unsafe because the explosive peroxides can concentrate in the residue.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.