A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
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.
=== Vasculitis === A link has been shown between ANCA-associated vasculitis and SNPs in the COL11A2 gene in a Genomewide Association Study. It is proposed that this association may be due to linkage disequilibrium between a SNP in the HLA-DP locus and SNPs in COL11A2. This is theorised as the SNP in the HLA molecule was found to be very strongly associated with these diseases with evidence for a single genetic association.
=== Chemistry === Pure lisinopril powder is white to off-white in color. Lisinopril is soluble in water (approximately 13 mg/L at room temperature), less soluble in methanol, and virtually insoluble in ethanol.
=== In Singapore === On 3 August, Arcturus Therapeutics confirmed that the company had received approval for a clinical trial of ARCT-154 and another vaccine called ARCT-165 in Singapore. The Phase I-II clinical trial will evaluate the vaccines as a primary vaccination series and a booster following first dose with Pfizer–BioNTech COVID-19 vaccine. The study is being partially funded by a grant from the Singapore Government.
==== Buddhism ==== Liu was a major patron of Tibetan Buddhism, allocating funds to repair temples, distribute alms, and even to pay stipends to monks studying in Lhasa and Kangding. Around 1939, he established the Xikang Buddhist Affairs Committee to settle disputes between monks and laypeople.
Sources: en.wikipedia.org
The beginning of this period is marked by the ascent of Mikhail Gorbachev to the position of General Secretary of the Communist Party of the Soviet Union. Seeking to bring an end to the economic stagnation associated with the Brezhnev Era, Gorbachev initiated economic reforms (perestroika), and political liberalization (glasnost). His rise coincided with a gradual thaw in relations with President Ronald Reagan's administration. Over four summit meetings between 1985 and 1988, the two leaders negotiated the Intermediate-Range Nuclear Forces Treaty, eliminating an entire class of nuclear weapons for the first time in the Cold War's history. Popular revolutions swept Eastern Europe in 1989, toppling Communist governments in Poland, Hungary, Czechoslovakia, and Romania. The sentiment culminated in the fall of the Berlin Wall on 9 November, which, in turn, reopened the long-dormant question of German unity. Within a year—following negotiations—the once politically distinctive countries of West Germany and East Germany were reunified into a single nation state that became a member of NATO. The Soviet Union itself did not survive the changes it had unleashed. Independence movements in the Baltic states and elsewhere gathered pace through 1990 and 1991, and a coup attempt by hardliners against Gorbachev in August 1991 accelerated rather than halted the union's disintegration that December.
=== Other uses === Leaves of the palm may be made into hats, mats, baskets, brooms and roof thatch for homes, and trunk wood, resistant to pests, for building construction. Tree trunks may be processed to yield dietary minerals. Comprising 80% of the fruit mass, açaí seeds may be ground for livestock food or as a component of organic soil for plants. Planted seeds are used for new palm tree stock, which, under the right growing conditions, can require months to form seedlings. Seeds may become waste in landfills or used as fuel for producing bricks.
The most pressing complications of type 1 diabetes are the always-present risks of poor blood sugar control: severe hypoglycemia and diabetic ketoacidosis. Hypoglycemia – typically blood sugar below 70 mg/dL (3.9 mmol/L) – triggers the release of epinephrine, and can cause people to feel shaky, anxious, or irritable. People with hypoglycemia may also experience hunger, nausea, sweats, chills, headaches, dizziness, and a fast heartbeat. Some feel lightheaded, sleepy, or weak. Severe hypoglycemia can develop rapidly, causing confusion, coordination problems, loss of consciousness, and seizure. On average, people with type 1 diabetes experience a hypoglycemia event that requires assistance of another 16–20 times in 100 person-years, and an event leading to unconsciousness or seizure 2–8 times per 100 person-years. The American Diabetes Association recommends treating hypoglycemia by the "15–15 rule": eat 15 grams of carbohydrates, then wait 15 minutes before checking blood sugar; repeat until blood sugar is at least 70 mg/dL (3.9 mmol/L). Severe hypoglycemia that impairs someone's ability to eat is typically treated with injectable glucagon, which triggers glucose release from the liver into the bloodstream. People with repeated bouts of hypoglycemia can develop hypoglycemia unawareness, where the blood sugar threshold at which they experience symptoms of hypoglycemia decreases, increasing their risk of severe hypoglycemic events.
== Effects of behavior == GnRH production/release is one of the few confirmed examples in which behavior influences hormones, rather than the other way around. Cichlid fish that become socially dominant in turn experience an upregulation of GnRH secretion whereas cichlid fish that are socially subordinate have a down regulation of GnRH secretion. Besides secretion, the social environment as well as their behavior affects the size of GnRH neurons. Specifically, males that are more territorial have larger GnRH neurons than males that are less territorial. Differences are also seen in females, with brooding females having smaller GnRH neurons than either spawning or control females. These examples suggest that GnRH is a socially regulated hormone. Multiple neuronal regions in the limbic system send signals to the hypothalamus to modulate the amount of GnRH production and the frequency of pulses. This provides a possible explanation for why psychic influences typically affect female sexual function.
=== Pain in mammals === In mutant yellow-orange mice and human redheads, both with nonfunctional MC1R, both genotypes display reduced sensitivity to noxious stimuli and increased analgesic responsiveness to morphine-metabolite analgesics. These observations suggest a role for mammalian MC1R outside the pigment cell, though the exact mechanism through which the protein can modulate pain sensation is not known. In a certain genetic background in mice it has been reported that animals lacking MC1R had increased tolerance to capsaicin acting through the TRPV1 receptor and decreased response to chemically induced inflammatory pain. Humans with MC1R mutations have been reported to need approximately 20% more inhalational anaesthetic than controls. Lidocaine was reported to be much less effective in reducing pain in another study of humans with MC1R mutations
Sources: en.wikipedia.org
Multiple factors can trigger HHS, including infection, myocardial infarction, and trauma, as well as infections in the respiratory, digestive, and urinary systems. Rising obesity rates and the greater consumption of high-carbohydrate beverages have both played a role in the increased incidence of HHS. Moreover, certain medications prescribed for different conditions have the potential to cause HHS. As with DKA, urgent medical treatment is necessary, commonly beginning with fluid volume replacement. On the whole, HHS is a medical emergency marked with hyperglycemia, hyperosmolarity, dehydration, and mild or no ketosis.
=== Archaeology in Neuchâtel during the 19th and 20th century === During the second half of the 19th century, many lake dwellings were found on the banks of lakes Neuchâtel, Bienne and Morat during a period dubbed "lake dwellings fever" (fièvre lacustre in french). The Jura waters correction lowered lake Neuchâtel height by 2.7 m which resulted in dozens of lake dwellings sites exiting from the waters. This made access to the artifacts far easier. Later, the construction of the A5 motorway (from Yverdon-les-Bains to Solothurn) alongside the north bank of Lake Neuchâtel led to the discovery of about 500'000 artifacts, many of them got included into the museum's collections.
== Gochujang hot-taste unit == Gochujang hot-taste unit (GHU) is a unit of measurement for the pungency (spicy heat) of gochujang, based on the gas chromatography and the high-performance liquid chromatography of capsaicin and dihydrocapsaicin concentrations. Gochujang products are assigned to one of the five levels of spiciness: Mild, Slight Hot, Medium Hot, Very Hot, and Extreme Hot.
Obsessional slowness is a controversial diagnosis, with presentations ranging from severe but common manifestations of obsessive compulsive disorder to catatonia. Down syndrome disintegrative disorder (or Down Syndrome Regression Disorder, DSDD / DSRD) is a chronic condition characterized by loss of previously acquired adaptive, cognitive and social functioning occurring in persons with Down syndrome, usually during adolescence or early adulthood. The clinical picture is variable, but often includes catatonic signs, which is why it was called "catatonic psychosis" in initial reports in 1946. DSDD seems to phenotypically overlap with obsessional slowness (see above) and catatonia-like regression occurring in ASD.
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.