A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-06-30. Anything still debated is marked as such rather than presented as settled.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
| 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 |
==== MeSH D12.125.154 – amino acids, neutral ==== MeSH D12.125.154.049 – asparagine MeSH D12.125.154.299 – cysteine MeSH D12.125.154.424 – glutamine MeSH D12.125.154.549 – methionine MeSH D12.125.154.800 – serine MeSH D12.125.154.900 – threonine
While other plants have δ15N values that range from 2 to 6‰, legumes have lower 14N/15N ratios (close to 0‰, i.e. atmospheric N2) because they can fix molecular nitrogen, rather than having to rely on soil nitrates and nitrites. Therefore, one potential explanation for lower δ15N values in human remains is an increased consumption of legumes or animals that eat them. 15N values increase with meat consumption, and decrease with legume consumption. The 14N/15N ratio could be used to gauge the contribution of meat and legumes to the diet.
I.E.M. (album) Inborn error of metabolism In-ear monitors, devices used by musicians, audio engineers and audiophiles to listen to music Incredible Expanding Mindfuck (Music) Information Engineering Methodology Institute of Electronic Music and Acoustics (Institut für Elektronische Musik und Akustik), part of the University of Music and Performing Arts, Graz Institute of Engineering and Management Integrated Enterprise Modeling Institute of Engineering in Medicine, part of the University of California, San Diego Institute for Experimental Mathematics, a central scientific facility of the University of Duisburg-Essen Intel Extreme Masters, a series of international esports tournaments International emergency medicine Internet Explorer Mobile Ion evaporation model, a model explaining electrospray ionization in mass spectrometry Iowa Electronic Markets Internal Energy Market, of the European Union
The AAV genome is built of single-stranded deoxyribonucleic acid (ssDNA), either positive- or negative-sensed, which is about 4.7 kilobase long. The genome comprises ITRs at both ends of the DNA strand, and two open reading frames (ORFs): rep and cap. The former is composed of four overlapping genes encoding Rep proteins required for the AAV life cycle, and the latter contains overlapping nucleotide sequences of capsid proteins: VP1, VP2 and VP3, which interact to form a capsid with icosahedral symmetry.
Modified bases occur in DNA. The first of these recognized was 5-methylcytosine, which was found in the genome of Mycobacterium tuberculosis in 1925. The reason for the presence of these noncanonical bases in bacterial viruses (bacteriophages) is to avoid the restriction enzymes present in bacteria. This enzyme system acts at least in part as a molecular immune system protecting bacteria from infection by viruses. Modifications of the bases cytosine and adenine, the more common and modified DNA bases, play vital roles in the epigenetic control of gene expression in plants and animals. A number of noncanonical bases are known to occur in DNA. Most of these are modifications of the canonical bases plus uracil.
Sources: en.wikipedia.org
=== Neutron activation === Molybdenum-99, which decays to form technetium-99m, can be formed by the neutron activation of molybdenum-98. When needed, other technetium isotopes are not produced in significant quantities by fission, but are manufactured by neutron irradiation of parent isotopes (for example, technetium-97 can be made by neutron irradiation of ruthenium-96).
== History == Dated back to 1956, the first protein modified transition metal catalyst was documented. The Palladium(II) salt was absorbed onto silk fibroin fiber, reduced by hydrogen to get the first reported ArM, which can catalyze asymmetric hydrogenation. This work was not reproducible, but it is considered to be the first work in the field of artificial metalloenzymes. At that time, the major challenge that blocked further studies was underdeveloped protein production and purification technology. The first attempt to anchor an abiotic metal center onto a protein was reported by Whitesides et al. using biotin-avidin interaction, making an artificial hydrogenase. The presence of avidin can significantly increase the catalytic capacity of Rhodium(I) cofactor in aqueous phosphate buffer. Another pioneering work was conducted by Kaiser et al. where carboxypeptidase A (CPA) was repurposed into an oxidase by substituting Zn(II) center by Cu(II), for the oxidation of ascorbic acid. The real potential of ArMs was unleashed when recombinant protein production was developed, namely in 1997 Distefano and Davies reported a scaffold modification of a recombinant adipocyte lipid-binding protein (ALBP) with iodoacetamido-1,10-phenanthroline coordinating Cu(II) for the stereoselective hydrolysis of racemic esters.
=== Venezuela === Colombia and neighbouring Venezuela have met regularly in the South American Championship, the Copa América and World Cup qualification. Colombia has historically held the superior head-to-head record, but the fixture has gained importance as Venezuela's national team became more competitive from the late 1990s. Venezuela's 1–0 victory in Barranquilla during 2006 World Cup qualification was regarded as a landmark result for the Venezuelan side. In 2026 World Cup qualification, Colombia won 1–0 in Barranquilla in September 2023 and 6–3 in Maturín in September 2025; the latter result eliminated Venezuela from contention for the CONMEBOL inter-confederation play-off place.
=== Antiviral properties === Peppermint has been shown to suppress viruses such as Influenza A, herpes simplex virus (HSV), and Vaccinia virus in laboratory studies. Mint extracts can also limit viral replication in HIV‑1, the most common strain of HIV.
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 a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.