heptapeptide 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.
Last reviewed on 2025-09-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
| 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 |
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
== Other animals == The prostate is found only in mammals. The prostate glands of male marsupials are proportionally larger than those of placental mammals. The presence of a functional prostate in monotremes is controversial, and if monotremes do possess functional prostates, they may not make the same contribution to semen as in other mammals. The structure of the prostate varies, ranging from tubuloalveolar (as in humans) to branched tubular. The gland is particularly well developed in carnivorans and boars, though in other mammals, such as bulls, it can be small and inconspicuous. In other animals, such as marsupials and small ruminants, the prostate is disseminate, meaning not specifically localisable as a distinct tissue, but present throughout the relevant part of the urethra; in other animals, such as red deer and American elk, it may be present as a specific organ and in a disseminate form. In some marsupial species, the size of the prostate gland changes seasonally. The prostate is the only accessory gland that occurs in male dogs. Dogs can produce in one hour as much prostatic fluid as a human can in a day. They excrete this fluid along with their urine to mark their territory. Additionally, dogs are the only species apart from humans seen to have a significant incidence of prostate cancer. The prostate is the only male accessory gland that occurs in cetaceans, consisting of diffuse urethral glands surrounded by a very powerful compressor muscle. The prostate gland originates with tissues in the urethral wall.
The lotus roots grow in pond or river bottom soil, while the leaves float on the water's surface or are held well above it. The leaf stalks (petioles) can be up to 200 cm (6 ft 7 in) long, allowing the plant to grow in water to that depth. The peltate leaf blade or lamina can have a diameter of 80–100 cm (2 ft 7 in – 3 ft 3 in). The leaves are spaced up to 2 m (6 ft 7 in) apart along the rhizome, which can grow as much as 20 m (66 ft) in one year. The internodes are not cylindrical but swollen in the middle.
=== Alanine === Alanine is produced by the transamination of one molecule of pyruvate using two alternate steps: 1) conversion of glutamate to α-ketoglutarate using a glutamate-alanine transaminase, and 2) conversion of valine to α-ketoisovalerate via Transaminase C. Not much is known about the regulation of alanine synthesis. The only definite method is the bacterium's ability to repress Transaminase C activity by either valine or leucine (see ilvEDA operon). Other than that, alanine biosynthesis does not seem to be regulated.
=== Secondary standards === Secondary standards do not satisfy the requirements for a primary standard. A standard solution created from a secondary standard cannot have its concentration accurately known without stoichiometric analysis against a primary standard. An example of a secondary standard is sodium hydroxide, a hydroscopic compound that is highly reactive with its surroundings. The concentration of a standard solution made with sodium hydroxide may fluctuate over time due to the instability of the compound, requiring for calibration using a primary standard before use.
Following three constitutional conferences, the British North America Act, 1867 officially proclaimed Canadian Confederation on July 1, 1867, initially with four provinces: Ontario, Quebec, Nova Scotia, and New Brunswick. Canada assumed control of Rupert's Land and the North-Western Territory to form the Northwest Territories, where the Métis' grievances ignited the Red River Rebellion and the creation of the province of Manitoba in July 1870. British Columbia and Vancouver Island (which had been united in 1866) joined the confederation in 1871 on the promise of a transcontinental railway extending to Victoria in the province within 10 years, while Prince Edward Island joined in 1873. In 1898, during the Klondike Gold Rush in the Northwest Territories, Parliament created the Yukon Territory. Alberta and Saskatchewan became provinces in 1905. Between 1871 and 1896, almost one quarter of the Canadian population emigrated south to the US. To settle the West and attract European immigrants, Canada sponsored the construction of three transcontinental railways, enacted the Dominion Lands Act and founded the North-West Mounted Police to maintain regional authority. This period of westward expansion and nation building resulted in the displacement of many Indigenous peoples of the Canadian Prairies to "Indian reserves", clearing the way for ethnic European block settlements. This caused the collapse of the Plains Bison in western Canada and the introduction of European cattle farms and wheat fields dominating the land.
Sources: en.wikipedia.org
For generic manufacturers, the act created a new approval mechanism, the Abbreviated New Drug Application (ANDA), in which the generic drug manufacturer need only demonstrate that their generic formulation has the same active ingredient, route of administration, dosage form, strength, and pharmacokinetic properties ("bioequivalence") as the corresponding brand-name drug. This act has been credited with, in essence, creating the modern generic drug industry. Concerns about the length of the drug approval process were brought to the fore early in the AIDS epidemic. In the mid and late 1980s, ACT-UP and other HIV activist organizations accused the FDA of unnecessarily delaying the approval of medications to fight HIV and opportunistic infections. Partly in response to these criticisms, the FDA issued new rules to expedite approval of drugs for life-threatening diseases, and expanded pre-approval access to drugs for patients with limited treatment options. All of the initial drugs approved for the treatment of HIV/AIDS were approved through these accelerated approval mechanisms. Frank Young, then commissioner of the FDA, was behind the Action Plan Phase II, established in August 1987 for quicker approval of AIDS medication. In two instances, state governments have sought to legalize drugs that the FDA has not approved.
=== Oceania === 14UD The Australian National University, Canberra, Australia SSAMS The Australian National University, Canberra, Australia ANTARES 10MV, STAR 2MV, Sydney, Australia Rafter Radiocarbon Laboratory, GNS Science, New Zealand Chronos 14Carbon-Cycle Facility, UNSW, Australia.
Nostalgia for the Soviet Union is gradually on the rise in Russia. Communist symbols continue to form an important part of the rhetoric used in state-controlled media, as banning on them in other countries is seen by the Russian foreign ministry as "sacrilege" and "a perverse idea of good and evil". The process of decommunization in Ukraine, a neighbouring post-Soviet state, was met with fierce criticism by Russia. The State Anthem of the Russian Federation, adopted in 2000 (the same year Vladimir Putin began his first term as president of Russia), uses the exact same music as the State Anthem of the Soviet Union, but with new lyrics written by Sergey Mikhalkov. Conversely, decommunization in Ukraine started during and after the dissolution of the Soviet Union in 1991. With the success of the Revolution of Dignity in 2014, the Ukrainian government approved laws that outlawed communist symbols. In July 2015, President of Ukraine Petro Poroshenko signed a set of laws that started a six-month period for the removal of communist monuments (excluding World War II monuments) and renaming of public places named after communist-related themes. At the time, this meant that 22 cities and 44 villages were set to get new names. In 2016, 51,493 streets and 987 cities and villages were renamed, and 1,320 Lenin monuments and 1,069 monuments to other communist figures removed. Violation of the law carries a penalty of a potential media ban and prison sentences of up to five years.
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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.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.