The short version of 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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
=== Taiwan === In October 2006, Taiwan banned ractopamine along with other beta-adrenergic agonists. In a 2012 climb-down, its legislature passed amendments to its Act Governing Food Sanitation, authorising government agencies to set safety standards for ractopamine. The Taiwanese Department of Health ultimately established an MRL of 10 ppb for ractopamine in beef on 31 July 2012. The American Institute in Taiwan, which represents US interests in Taiwan, states that these "and many other countries have determined that meat from animals fed ractopamine is safe for human consumption"; this is in the context of an ongoing trade dispute between Taiwan and the US on this subject, which threatened to prevent Taiwan's entry to the Trans-Pacific Partnership trade pact. In 2020, restrictions on imports of US pork with ractopamine were relaxed, leading to protests. A referendum took place on December 18, 2021, deciding whether to ban the import of pork with ractopamine, and the ban was rejected.
Prigozhin denied the allegations in a Telegram statement on 15 May, while the Kremlin described the report as a hoax. The Ukrainian air force said it destroyed 25 drones and three cruise missiles in another massive overnight attack by Russia. Seven people were killed and another 16 were injured in Russian shelling in Donetsk and Kherson oblasts. Russian-installed officials said mobile internet was temporarily suspended in occupied areas of Luhansk oblast due to increased shelling by Ukrainian troops.
The end point of translational research in medicine is the production of a promising new treatment that can be used clinically. Translational research is conceived due to the elongated time often taken to bring to bear discovered medical idea in practical terms in a health system. It is for these reasons that translational research is more effective in dedicated university science departments or isolated, dedicated research centers. Since 2009, the field has had specialized journals, the American Journal of Translational Research and Translational Research dedicated to translational research and its findings. Translational research in biomedicine is broken down into different stages. In a two-stage model, T1 research, refers to the "bench-to-bedside" enterprise of translating knowledge from the basic sciences into the development of new treatments and T2 research refers to translating the findings from clinical trials into everyday practice, although this model is actually referring to the 2 "roadblocks" T1 and T2. Waldman et al. propose a scheme going from T0 to T5. T0 is laboratory (before human) research. In T1-translation, new laboratory discoveries are first translated to human application, which includes phase I & II clinical trials. In T2-translation, candidate health applications progress through clinical development to engender the evidence base for integration into clinical practice guidelines. This includes phase III clinical trials. In T3-translation, dissemination into community practices happens.
== Analogs == Structural analogs of desmethylprodine with different N-substituents than a methyl group on the piperidine have been investigated. Several of these have significantly greater in vitro potency compared to desmethylprodine.
==== Nanofiber self-assembly ==== Molecular self-assembly is one of the few methods for creating biomaterials with properties similar in scale and chemistry to that of the natural in vivo extracellular matrix (ECM), a crucial step toward tissue engineering of complex tissues. Moreover, these hydrogel scaffolds have shown superiority in in vivo toxicology and biocompatibility compared to traditional macro-scaffolds and animal-derived materials.
Sources: en.wikipedia.org
In cases of chronic arsenic exposure, the nitric oxide levels are depleted, due to the superoxide reactions. The enzyme NO synthase (NOS) uses L-arginine to form nitric oxide, but this enzyme is inhibited by monomethylated arsenic (III) compounds.
Eukaryotic algae contain chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular DNA like that in cyanobacteria and are interpreted as representing reduced endosymbiotic cyanobacteria. However, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. Many groups contain some members that are no longer photosynthetic. Some retain plastids, but not chloroplasts, while others have lost plastids entirely.
He and his teammates were initially found not guilty in March 2015 by the AFL Anti-Doping Tribunal, but a guilty verdict was returned in January 2016 after an appeal by the World Anti-Doping Agency. He was suspended for two years which, with backdating, ended in November 2016; as a result, he served approximately fourteen months of his suspension and missed the entire 2016 AFL season. The suspension sparked speculation that Hooker would leave Essendon as a free agent, but he signed a new five-year contract with Essendon in April 2016, rejecting larger offers from several other clubs. On 17 August 2021, Hooker announced that he would retire at the end of this season.
One theory is that because bisphosphonates are preferentially deposited in bone with high turnover, it is possible that the levels of bisphosphonate within the jaw are selectively elevated. To date, there have been no reported cases of bisphosphonate-associated complications within bones outside the craniofacial skeleton.
Sources: en.wikipedia.org
Likewise, polymeric residue can contribute to a similar decrease in the thermal conductivity of suspended graphene to approximately 500 – 600 W⋅m−1⋅K−1 for bilayer graphene. Isotopic composition, specifically the ratio of 12C to 13C, significantly affects graphene's thermal conductivity. Isotopically pure 12C graphene exhibits higher thermal conductivity than either a 50:50 isotope ratio or the naturally occurring 99:1 ratio. It can be shown by using the Wiedemann–Franz law, that the thermal conduction is phonon-dominated. However, for a gated graphene strip, an applied gate bias causing a Fermi energy shift much larger than kBT can cause the electronic contribution to increase and dominate over the phonon contribution at low temperatures. The ballistic thermal conductance of graphene is isotropic. Graphite, a 3D counterpart to graphene, exhibits a basal plane thermal conductivity exceeding 1000 W⋅m−1⋅K−1 (similar to diamond), In graphite, the c-axis (out of plane) thermal conductivity is over a factor of ~100 smaller due to the weak binding forces between basal planes as well as the larger lattice spacing. In addition, the ballistic thermal conductance of graphene is shown to give the lower limit of the ballistic thermal conductance, per unit circumference, length of carbon nanotubes. Graphene's thermal conductivity is influenced by its three acoustic phonon modes: two linear dispersion relation dispersion relation in-plane modes (LA, TA) and one quadratic dispersion relation out-of-plane mode (ZA).
=== Cultivation === White-barked birches in particular are cultivated as ornamental trees, largely for their appearance in winter. The Himalayan birch, Betula utilis, especially the variety or subspecies jacquemontii, is among the most widely planted for this purpose. It has been cultivated since the 1870s, and many cultivars are available, including 'Doorenbos', 'Grayswood Ghost' and 'Silver Shadow'; 'Knightshayes' has a slightly weeping habit. Other species with ornamental white bark include Betula ermanii, Betula papyrifera, Betula pendula and Betula raddeana.
=== Other types === A further class of alcohol dehydrogenases belongs to quinoenzymes and requires quinoid cofactors (e.g., pyrroloquinoline quinone, PQQ) as enzyme-bound electron acceptors. A typical example for this type of enzyme is methanol dehydrogenase of methylotrophic bacteria.
Over six of these private airline firms offer commercial flights to both domestic and international locations, including Daallo Airlines, Jubba Airways, African Express Airways, East Africa 540, Central Air and Hajara. In 2025, it was announced that Somali Airlines would be making a return with the acquisition of two Airbus A320 aircraft. Possessing the longest coastline on the continent, Somalia has several major seaports. Maritime transport facilities are found in the port cities of Mogadishu, Bosaso, Berbera, Kismayo and Merca. There is also one merchant marine. Established in 2008, it is cargo-based.
=== 1925: White Castle Official House Organ, success, expansion and imitators === The company also began publishing its own internal employee magazine, the White Castle Official House Organ, circa November 1925 (it was originally named The Hot Hamburger). The bulk of the material was contributed by company personnel and consisted mostly of letters and photographs of workers, promotional announcements, 25-year milestones, retirements, and similar items of interest arranged by geographic area. "Employees could... read about the progress and innovations made by those in other areas which made everyone aware of the entire system's direction and condition." The White Castle Official House Organ was published quarterly at least through the early 1980s, and at some point was renamed The Slider Times. The Ohio History Connection houses an extensive archive of White Castle System, Inc. records from 1921 to 1991, including issues dating from 1927 to 1970 of the White Castle Official House Organ.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
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.