lyophilized powder 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.
Updated 2026-01-27. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
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.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
=== Factors with no effect === BV is designed to ignore variation in digestibility of a food — which in turn largely depends on the food preparation. For example, compare raw soy beans and extracted soy bean protein. The raw soy beans, with tough cell walls protecting the protein, have a far lower digestibility than the purified, unprotected, soy bean protein extract. As a foodstuff far more protein can be absorbed from the extract than the raw beans, however the BV will be the same. The exclusion of digestibility is a point of misunderstanding and leads to misrepresentation of the meaning of a high or low BV.
Another common demonstration is suspending a ball in a jet or plume of air. It is often claimed that this is due to the air in the plume having lower pressure since it is moving faster. However, the air in the plume has the same pressure as the surrounding air. The ball remains in the plume since as it moves away from the center of the plume it experiences an asymmetric air flow which pushes it back toward the center. Other common classroom demonstrations, such as blowing between two suspended spheres, or inflating a large bag are sometimes explained in a similarly misleading manner by saying "faster moving air has lower pressure".
=== Follicular phase === GnSAF prevents a pre-ovulatory surge in LH during this time, allowing sufficient time for the dominant follicle to mature before ovulation. At the start of the follicular phase, high serum FSH concentrations stimulate the development and proliferation of the granulosa cells of the small antral follicles, resulting in a steady increase in GnSAF biosynthesis. The relatively high GnSAF bioactivity dampens the response of the pituitary gland to GnRH by antagonising the sensitising effects of estradiol on the pituitary gland. The GnRH pulse, in the presence of GnSAF, is not frequent or potent enough to stimulate LH secretion from the anterior pituitary above basal levels.
=== Stage V: Sequelae === The disease is over, but sequelae from the gangrenous and scarring stages remain. Tissue may be missing, teeth may still be exposed, and the face may be disfigured. The patient may have difficulty eating, drinking, and speaking. Teeth may become set in the wrong places, or be lost altogether. There may still be problems with drooling and with opening/closing the jaw. Reconstructive surgery is an option at this phase. Social reintegration is also very important.
Through this catabolic process, GSNOR regulates the cellular concentrations of GSNO and plays a central role in regulating the levels of endogenous S-nitrosothiols and controlling protein S-nitrosylation-based signaling. As an example of S-nitrosylation-based signaling, Barglow et al. showed that GSNO selectively S-nitrosylates reduced thioredoxin at cysteine 62. Nitrosylated thioredoxin, via directed protein-protein interaction, trans-nitrosylates the active site cysteine of caspase-3 thus inactivating caspase-3 and preventing induction of apoptosis. As might be expected of an enzyme involved in regulating NO levels and signaling, pleiotropic effects are observed in GSNOR knockout models. Deleting the GSNOR gene from both yeast and mice increased the cellular levels of GSNO and nitrosylated proteins, and the yeast cells showed increased susceptibility to nitrosative stress. Null mice show increased levels of S-nitrosated proteins, increased beta adrenergic receptor numbers in lung and heart, diminished tachyphylaxis to β2-adrenergic receptor agonists, hyporesponsiveness to methacholine and allergen challenge and reduced infarct size after occlusion of the coronary artery. In addition, null mice show increased tissue damage and mortality following challenge with bacteria or endotoxin and are hypotensive under anesthesia yet normotensive in the conscious state.
Sources: en.wikipedia.org
Many exiled Poles could not return to the country for which they had fought because they belonged to political groups incompatible with the new communist regimes, or because they originated from areas of pre-war eastern Poland that were incorporated into the Soviet Union (see Polish population transfers (1944–1946)). Some were deterred from returning simply on the strength of warnings that anyone who had served in military units in the West would be endangered. Many Poles were pursued, arrested, tortured and imprisoned by the Soviet authorities for belonging to the Home Army or other formations (see Anti-communist resistance in Poland (1944–1946)), or were persecuted because they had fought on the Western front.
=== United States === Similar to the law of Canada, the U.S. law (27 CFR 5.148) says that tequila must be "made in Mexico, in compliance with the laws and regulations of Mexico governing the manufacture of Tequila for consumption in that country."
=== Electrodiagnostic testing === Electromyography (EMG) and nerve conduction studies help distinguish myopathic from neurogenic causes of weakness and may show characteristic myopathic motor unit potentials or myotonic discharges. A myopathic EMG combined with proximal weakness and hyperCKemia substantially increases the likelihood of a positive muscle biopsy, although a normal EMG does not exclude myopathy.
=== Development === On January 31, 2023, it was announced that a remake version of Matlock was in development, and Jennie Snyder Urman signed on to write a pilot episode to be aired by CBS. Urman is expected to executive produce alongside Joanna Klein, Eric Christian Olsen, and Kathy Bates. On May 9, 2023, the Matlock remake was given a series order. The series is developed by Urman. John Will and Kat Coiro were added as executive producers. Coiro also directed the pilot. Production companies involved with the series are Sutton Street, Cloud Nine, and CBS Studios. Matlock was moved to the 2024–25 season due to strike-related production delays. It was later reported that it was a 19-episode order. On October 22, 2024, CBS renewed the series for a second season. Though set in New York City, the show is filmed at Paramount Studios in California after the pilot was shot in Toronto. On January 22, 2026, CBS renewed the series for a third season.
Sources: en.wikipedia.org
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.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.