The short version of Pro-Gly-Pro tail fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-14 and is reviewed periodically as new material appears.
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.
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.
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.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
| 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 |
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.
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.
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.
==== Objective Colour Analysis ==== Objective colour analysis can be performed using digital images taken with a digital camera, either in the field or in a laboratory. This method was developed to replace subjective colour reporting, such as by-eye observations, with quantitative RGB and HSV values. The method has previously been demonstrated on the thermal treatment of uranyl peroxide powders, which yield distinctive yellow to brown hues. Hence, this method is noted as particularly useful in determining thermal processing history, especially where colour changes occur in uranium compounds of various oxidation states.
== Interactions == The enzymes in NexoBrid inhibit the liver enzymes CYP2C8 and CYP2C9 when ingested. These are involved in the breaking down of a number of drugs, including amiodarone, chloroquine, ibuprofen, and warfarin. It is not known whether this mechanism has any clinical relevance.
== In popular culture == In Monty Python's Life of Brian (1979), some people mishear parts of the Sermon on the Mount's beatitudes, including "Blessed are the cheesemakers" rather than "Blessed are the peacemakers" (Matthew 5:9). Cheesemaking has served as the theme of several fictional works and games. This includes Fromage, a 2024 strategy board game.
Hydrothermal circulation occurs within the Earth's crust wherever fluid becomes heated and begins to convect. These fluids are thought to reach supercritical conditions under a number of different settings, such as in the formation of porphyry copper deposits or high temperature circulation of seawater in the sea floor. At mid-ocean ridges, this circulation is most evident by the appearance of hydrothermal vents known as "black smokers". These are large (metres high) chimneys of sulfide and sulfate minerals which vent fluids up to 400 °C. The fluids appear like great black billowing clouds of smoke due to the precipitation of dissolved metals in the fluid. It is likely that at that depth many of these vent sites reach supercritical conditions, but most cool sufficiently by the time they reach the sea floor to be subcritical. One particular vent site, Turtle Pits, has displayed a brief period of supercriticality at the vent site. A further site, Beebe, in the Cayman Trough, is thought to display sustained supercriticality at the vent orifice.
Carbon has the highest melting point of any element, and in carbon arc lamps it had been demonstrated to produce incandescence fairly close to that of sunlight. However, carbon has a tendency to sublimate before reaching its melting point depending on pressure, which led to rapid blackening of vacuumed bulbs. The first commercially successful light bulb filaments were made from carbonized paper or bamboo. Carbon filaments have a negative temperature coefficient of resistance—as they get hotter, their electrical resistance decreases. This made the lamp sensitive to fluctuations in the power supply, since a small increase of voltage would cause the filament to heat up, reducing its resistance and causing it to draw even more power and heat even further. Carbon filaments were "flashed" by heating in a hydrocarbon vapor (usually gasoline), to improve their strength and uniformity. Metallized or "graphitized" filaments were first heated to high temperature to transform them into graphite, which further strengthened and smoothed the filament. These filaments have a positive temperature coefficient, like a metallic conductor, which stabilized the lamps operating properties against minor variations in supply voltage. Metal filaments were tried in 1897 and started to displace carbon starting around 1904. Tungsten has the highest available melting point, but brittleness was an obstacle. By 1910, a process was developed by William D. Coolidge at General Electric for production of a ductile form of tungsten.
Sources: en.wikipedia.org
==== Cubans call for Urquía Carreño to resign ==== On January 12, 2024, after the document was sent out by the Board to the larger community of Cuban Freemasons, a group of 18 Lodge Masters from all over Cuba demanded the immediate resignation of Urquía Carreño. When the robbery was made public, Llansó received large donations of food from other Freemasons and the Daughters of Acacia. Urquía Carreño refused to step down, and asked the Freemasons of Cuba to remain patient while the investigation was underway. Instead of stepping down, Urquía Carreño sent all 18 of those Lodge Masters to be sent in front of the Supreme Court of Masonic Justice for trials and investigations, and also ordered Viñas Alonso to be tried by the Supreme Court.
=== Inflammation === CCN1 promotes the apoptotic functions of inflammatory cytokines such as TNFα, FasL, and TRAIL. It also reprograms macrophages towards M1 polarization through αMβ2-mediated activation of NF-κB. CCN1 is upregulated in patients with Crohn's disease and ulcerative colitis. CCN1 supports the patrolling behavior of murine resident Ly6Clow monocytes along the endothelial in the steady state and is required for their accumulation under viral-mimicking vascular inflammation.
== Clinical significance == Haptotaxis plays a major role in the efficient healing of wounds. For example, when corneal integrity is compromised, epithelial cells quickly cover the damaged area by proliferation and migration (haptotaxis). In the corneal stroma, keratocytes within the wounded area undergo apoptosis, leaving the stroma devoid of cells that must be replaced. Keratocytes surrounding the wounded area proliferate and become fibroblasts that migrate to fill the wounded area. This creates a healthy environment with myofibroblasts and extracellular matrix. This is known as light backscattering or subepithial haze. When there is injury to an epithelial cell heptotaxis occurs, which is highly influenced by the cell's velocity, which is in turn influenced by direction of cell motility. Cells migrate easily and quickly in packs, so when one cell moves the rest follow in response to the gradient and initial cell movement. Mechanical effects like the buildup of tensile forces may play an important role for both division as well as motility of cells in tissue.
Rearing a relatively small number of grazing animals can be beneficial, as the Food Climate Research Network at Surrey University reports: "A little bit of livestock production is probably a good thing for the environment". In May 2009, Ghent, Belgium, was reported to be "the first [city] in the world to go vegetarian at least once a week" for environmental reasons, when local authorities decided to implement a "weekly meatless day". Civil servants would eat vegetarian meals one day per week, in recognition of the United Nations' report. Posters were put up by local authorities to encourage the population to take part on vegetarian days, and "veggie street maps" were printed to highlight vegetarian restaurants. In September 2009, schools in Ghent are due to have a weekly veggiedag ("vegetarian day") too. Public opinion and acceptance of meat-free food is expected to be more successful if its descriptive words focus less on the health aspects and more on the flavor.
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.
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.