This is a working overview of Semax, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-27 and is reviewed periodically as new material appears.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
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.
40. Pain Physician. 2026 Sep;29(6):E751. Comment on "Cervical Erector Spinae Plane Block vs. Epidural Steroid Injection for Cervical Radicular Pain: A Clinical Trial". Sacaklidir GY(1), Sacaklidir R(2). Author information: (1)Cam and Sakura City Hospital, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey. (2)Sisli Hamidiye Etfal Training and Research Hospital, Department of Physical Medicine and Rehabilitation, Pain Management Section, Istanbul, Turkey.
=== Eight others === Synthesis of americium, berkelium, and californium followed soon. Einsteinium and fermium were discovered by a team of scientists led by Albert Ghiorso in 1952 while studying the composition of radioactive debris from the detonation of the first hydrogen bomb. The isotopes synthesized were einsteinium-253, with a half-life of 20.5 days, and fermium-255, with a half-life of about 20 hours. The creation of mendelevium, nobelium, and lawrencium followed.
=== Military lull (August) === Active hostilities slowed in August 2026, when the formal 60-day deadline set by the June MoU officially expired. The Strait of Hormuz remained disrupted during this period and mediators Oman and Qatar were involved in backdoor diplomacy, slowing world energy shipping to a fraction of its pre-war volume.
On 23 January 2026, Danish prime minister Mette Frederiksen visited Greenland to express support for the people and the island's self-governing government, following comments by US president Donald Trump indicating his willingness to annex the territory. Trump had previously discussed strengthening security in the Arctic region with NATO secretary general Mark Rutte. Both the Danish and Greenlandic governments have affirmed that the island's sovereignty is indisputable, but remain open to discussions on issues such as security and economic development. The crisis eased after Trump withdrew threats of force and new tariffs.
Sources: pubmed.ncbi.nlm.nih.gov
Clinically, venom of this snake does not usually cause local effects at the bite site and is usually painless. However, the etiology progresses to systemic neurotoxic and myalgic symptoms, with frequent kidney failure accompanied by acute tubular necrosis. The huge area of distribution, potent venom in fairly large quantities and a definite willingness to defend themselves are important factors in their dangerousness. In Brazil and probably also in other countries in their area of distribution, this species is probably the most dangerous rattlesnake. After the fer-de-lance (Bothrops asper), it is the most common cause of snake envenoming. In the first half of the 20th century as well as in the 1950s and 1960s, 12% of treated cases ended fatally. Untreated cases apparently had a mortality rate of 72% in the same period, but this was due to the fact that there was no antivenom, poor medical care and neglect (Rosenfeld, 1971). In more recent times, an average of 20,000 snakebites are registered each year in Brazil, almost 10% of them caused by the neotropical rattlesnake. The mortality rate is estimated at 3.3% and is thus much lower than in the past (Ribeiro, 1990b). A study from southeastern Brazil documented only one fatality from 87 treated cases (Silveira and Nishioka, 1992).
== Awards == Borden Award (American Chemical Society) 1957 Bond Award (American Oil Chemists’ Society) 1973 Agricultural and Food Chemistry Award (American Chemical Society) 1973 Senior Scientist Award (Alexander von Humboldt Foundation) 1981 Macy-Gyorgy Award for Research in Human Milk and Lactation 1997 Penn State Alumni Fellow Award 2001 Penn State Distinguished Alumnus Award 2002
The total weight of the breast tissues removed was 44.8 kilograms (99 lb). Another extreme case was observed in 2008 in Maria Vittoria Hospital in Turin, Italy, where the amount removed from both breasts was 17.2 kg (38 lb). The growth occurred during puberty making it a case of juvenile gigantomastia, but the patient did not seek treatment until the age of 29. Another extreme case was observed on August 28, 2003, when a 24-year-old woman was admitted to the Clinical Center Skopje in North Macedonia with gigantomastia of pregnancy and the amount later removed from both breasts was 15 kg (33 lb) in total. A second case in North Macedonia was reported when the breasts of a 30-year-old woman from a remote mountain village in eastern North Macedonia suddenly grew to more than 30 kilograms (66 lb) total. As the disorder becomes more widely known, media reports have increased. French Canadian Isabelle Lanthier appeared on Montel Williams' talk show where she told how her chest grew from 86 cm (34 in) to 133 cm (52 in) in five months during her pregnancy. At their largest, one breast weighed 6.8 kg (15 lb) and the other 5.4 kg (12 lb). Her husband custom-made a special bra to support her breasts. In 2007, a Chilean TV station covered the story of 32-year-old Yasna Galleguillos from Antofagasta, who experienced ongoing back pain, making everyday tasks very difficult to perform. She underwent breast reduction surgery to relieve her pain. Surgeons removed 4.25 kilograms (9.4 lb) from one breast and 3.33 kilograms (7.3 lb) from the other breast.
Electroconvulsive therapy can differ in its application in three ways: electrode placement, frequency of treatments, and the electrical waveform of the stimulus. These three forms of application have significant differences in both adverse side effects and symptom remission. After treatment, drug therapy is usually continued, and some patients receive maintenance ECT. ECT appears to work in the short term via an anticonvulsant effect mostly in the frontal lobes, and longer term via neurotrophic effects primarily in the medial temporal lobe.
=== Backing === Since finer turquoise is often found as thin seams, it may be glued to a base of stronger foreign material for reinforcement. These stones are termed "backed", and it is standard practice that all thinly cut turquoise in the Southwestern United States is backed. Native indigenous peoples of this region, because of their considerable use and wearing of turquoise, have found that backing increases the durability of thinly cut slabs and cabochons of turquoise. They observe that if the stone is not backed it will often crack. Backing of turquoise is not widely known outside of the Native American and Southwestern United States jewellery trade. Backing does not diminish the value of high quality turquoise, and indeed the process is expected for most thinly cut American commercial gemstones.
Sources: en.wikipedia.org
=== Embryology === Retinoic acid via the retinoic acid receptor influences the process of cell differentiation and, hence, the growth and development of embryos. During development, there is a concentration gradient of retinoic acid along the anterior-posterior (head-tail) axis. Cells in the embryo respond to retinoic acid differently depending on the amount present. For example, in vertebrates, the hindbrain transiently forms eight rhombomeres and each rhombomere has a specific pattern of genes being expressed. If retinoic acid is not present the last four rhombomeres do not develop. Instead, rhombomeres 1–4 grow to cover the same amount of space as all eight would normally occupy. Retinoic acid has its effects by turning on a differential pattern of Homeobox (Hox) genes that encode different homeodomain transcription factors which in turn can turn on cell type-specific genes. Deletion of the Homeobox (Hox-1) gene from rhombomere 4 makes the neurons growing in that region behave like neurons from rhombomere 2. Retinoic acid is not required for patterning of the retina as originally proposed, but retinoic acid synthesized in the retina is secreted into the surrounding mesenchyme where it is required to prevent overgrowth of perioptic mesenchyme which can cause microphthalmia, defects in the cornea and eyelid, and rotation of the optic cup.
Photoactivated peptides are modified natural or synthetic peptides whose functions can be activated or controlled using light. These peptides incorporate light-sensitive elements that allow for precise regulation their biological activity in both space and time. The activation can be either irreversible, as in the case of caged peptides with photocleavable protecting groups, or reversible, utilizing molecular photoswitches like azobenzenes or diarylethenes, and diarylethenes By incorporating these light-responsive components into the peptide structure, peptide properties, functions, and biological activities can be manipulated with high precision. This approach enables targeted activation of peptides in specific areas, making photoactivated peptides valuable tools for applications in cancer therapy, drug delivery, and probing molecular interactions in living cells and in organisms.
=== Lymphatic drainage === Approximately 75% of the lymph from the breast travels to the axillary lymph nodes on the same side of the body, while 25% of the lymph travels to the parasternal nodes (beside the sternum bone). A small amount of remaining lymph travels to the other breast and to the abdominal lymph nodes. The subareolar region has a lymphatic plexus known as the "subareolar plexus of Sappey". The axillary lymph nodes include the pectoral (chest), subscapular (under the scapula), and humeral (humerus-bone area) lymph-node groups, which drain to the central axillary lymph nodes and to the apical axillary lymph nodes. The lymphatic drainage of the breasts is especially relevant to oncology because breast cancer is common to the mammary gland, and cancer cells can metastasize (break away) from a tumor and be dispersed to other parts of the body by means of the lymphatic system.
Creatine kinase (CK), also known as creatine phosphokinase (CPK) or phosphocreatine kinase, is an enzyme (EC 2.7.3.2) expressed by various tissues and cell types. CK catalyses the conversion of creatine and uses adenosine triphosphate (ATP) to create phosphocreatine (PCr) and adenosine diphosphate (ADP). This CK enzyme reaction is reversible and thus ATP can be generated from PCr and ADP. In tissues and cells that consume ATP rapidly, especially skeletal muscle, but also brain, photoreceptor cells of the retina, hair cells of the inner ear, spermatozoa and smooth muscle, PCr serves as an energy reservoir for the rapid buffering and regeneration of ATP in situ, as well as for intracellular energy transport by the PCr shuttle or circuit. Thus creatine kinase is an important enzyme in such tissues. Clinically, creatine kinase is assayed in blood tests as a marker of damage of CK-rich tissue such as in myocardial infarction (heart attack), rhabdomyolysis (severe muscle breakdown), muscular dystrophy, autoimmune myositides, and acute kidney injury.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.