If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 |
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.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
=== Calibration === Continuous glucose monitoring systems do not always produce readings identical to those obtained through fingerstick blood glucose testing. Differences between CGM and fingerstick values are expected due to physiological and technical factors, including the lag time between glucose levels in interstitial fluid and those in capillary blood. While the Dexcom G7 has a reported MARD of approximately 8.2%, variations of up to 20% between CGM and fingerstick readings are considered within the normal accuracy range. These differences are particularly noticeable during periods of rapid glucose change, such as after meals, physical activity, or insulin administration. As a result, CGM readings are most reliable when glucose levels are stable, and discrepancies may occur during times of fluctuation. There is an option to calibrate using a blood glucose reading taken from another device such as a blood glucose meter that uses a fingerstick lancing device, but it is not mandatory on any currently available Dexcom CGMs. The "20 rule" (or 20/20 rule) is commonly used to assess the accuracy of the CGM. If the difference between the Dexcom G6 or G7 reading and the fingerstick blood glucose meter value is within 20% (or 20 mg/dL when glucose levels are under 80 mg/dL), the sensor is operating within its expected error margin. While CGM and meter readings may not match exactly, they should generally fall within this acceptable range, especially when glucose levels are stable.
=== Nuclear actin === Nuclear actin was first noticed and described in 1977 by Clark and Merriam. Authors describe a protein present in the nuclear fraction, obtained from Xenopus laevis oocytes, which shows the same features as skeletal muscle actin. Since that time there have been many scientific reports about the structure and functions of actin in the nucleus. The controlled level of actin in the nucleus, its interaction with actin-binding proteins (ABP) and the presence of different isoforms allows actin to play an important role in many important nuclear processes.
=== Drug lead optimization === Thermofluor measurements of Tm can be quantitatively related to drug Kd values, although this requires the additional calorimetric measurements of the target proteins' enthalpy of unfolding, determined using DSC. The dynamic range of the Thermofluor assay is very large, so that the same assay can be used to find micromolar hits and to optimize sub-nanomolar leads, making the method particularly useful in the development of QSAR relationships for lead optimization.
molecules such as antibodies (immunoglobulins), which interact directly with antigens. molecules of the major histocompatibility complex (or MHC), which are expressed on the surface of cells and interact with T cells as part of the adaptive immune response. Sialyl-Lewis X antigen on the surface of leukocytes. H antigen of the ABO blood compatibility antigens. Other examples of glycoproteins include:
Sources: en.wikipedia.org
==== Current neuroimaging evidence ==== The task of elucidating the exact role of claustrum in mediating sensory information and conscioussness remains a topic of active debate. And findings on whether distruptions of claustral activity lead to the loss of consciousness are conflicting. Recent imaging studies have confirmed the suspected complexity and multi-regional character of specifically KOR-mediated alterations, and argued that the neural substrates involve cortico-thalamic integration and default mode network (DMN) disruption rather than claustrum-centric mechanism. Salvinorin A induces decreases in default mode network connectivity, specifically within the medial prefrontal cortex and posterior cingulate cortex and increased between-network connectivity with reduced dynamic connectivity stability. While both salvinorin A and psilocybin attenuate default mode network connectivity, their effects on thalamocortical networks differ; salvinorin A-induced thalamic modulation is independent of 5-HT2A receptor activation. The thalamus, especially the centromedian, paraventricular, and centrolateral nucleus, expresses high KOR density and mediates cortical arousal, viscero-limbic integration, and relay of sensory and interoceptive information to cortical processing hierarchies. KOR activation within these thalamic nuclei reduces the relay of exteroceptive and interoceptive information to the cortex, producing the characteristic dissociation from external reality and loss of contact with self-representation and body schema.
==== United States ==== 4-HO-DPT is not an explicitly controlled substance in the United States. However, the drug is a close analogue of psilocin (4-HO-DMT), which is a Schedule I controlled substance in this country, and hence sale for intended human consumption could be illegal under the Federal Analogue Act.
== In popular culture == In Winter Light (1963), directed by Ingmar Bergman, the church sexton Algot Frövik was modeled on prop master K.A. Bergman, whose Bekhterev's disease (ankylosing spondylitis) served as the basis for the character's illness. The Oxbow Cure (2013) follows Lena, a woman recently diagnosed with ankylosing spondylitis as she comes to terms with the disease while living in rural Ontario.
According to Rhie, the "Cave of the Musicians" is probably the earliest of the "central pillar" caves at Kizil, dated to the mid-4th century CE, and its iconography is also among the earliest. Carbon testing by Su Bai gave dates ranging from 310 +/-80 CE to 350 +/-60 CE (i.e. a maximum range of 230-410 CE). Huo and Wang attributed the cave to the Second Period, giving it a date from mid-4th to late 5th century (circa 350–499 CE). The traditional German datation estimated the cave to be from the 600–650 CE period, and presented it as an example of the later "Blue-green style", said to succeed chronologically the "Orange-green style" group. The so-called "central pillar" which appears on a plan is actually not a pillar at all but only the rock at the back of the cave, into which was bored a circular corridor allowing for circumambulation. There is a niche in the "central pillar" designed to house a statue of the Buddha, and two other niches on each side of the main entrance, and niches in the back corridor. The central niche probably depicted the Buddha meditating in the Indrasala Cave, with a background decoration of a mountain, a recurring central theme at Kizil. Maitreya, the Buddha of the future, in the Tusita Heaven, appears in a beautiful mural over the exit door. Structurally, the cave remains relatively simple, as it does not have an anteroom or vestibule. The style of the paintings is derived from the Art of Gandhara and Kashmir, the Art of Mathura and early Gupta art, with striking influences from Roman art and the art of Palmyra.
== Marketing as dietary supplement == Patrick Arnold reintroduced methylhexanamine in 2006 as a dietary supplement, after the final ban of ephedrine in the United States in 2005. Arnold introduced it under the trademarked name Geranamine, a name held by his company, Proviant Technologies. A large number of supplements focusing on fat loss and workout energy (thermogenic or general-purpose stimulants) used the ingredient in concert with other substances such as caffeine, a combination similar to the combination of ephedrine and caffeine. Methylhexanamine-containing supplements sometimes list "geranium oil" or "geranium extract" as a source of methylhexanamine. However, geranium oils do not contain methylhexanamine, and the methylhexanamine in these supplements is added in the form of synthetic material. A variety of studies have explored the possibility that DMAA is found in some types of geraniums, but at present, high quality evidence of DMAA's presence in plants is lacking. Methylhexanamine is synthesized by reacting 4-methylhexan-2-one with hydroxylamine, which converts the 4-methylhexan-2-one to 4-methylhexan-2-one oxime, which is reduced via catalytic hydrogenation; the resulting methylhexanamine can be purified by distillation.
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.
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.