lyophilised 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 2026-01-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
The European Union and Japan also reviewed safety and concluded – as had the United States – that there was insufficient evidence to set an upper limit for vitamin K. For US food and dietary supplement labeling purposes, the amount in a serving is expressed as a percentage of daily value. For vitamin K labeling purposes, 100% of the daily value was 80 μg, but on 27 May 2016 it was revised upwards to 120 μg, to bring it into agreement with the highest value for adequate intake. Compliance with the updated labeling regulations was required by 1 January 2020 for manufacturers with US$10 million or more in annual food sales, and by 1 January 2021 for manufacturers with lower volume food sales. A table of the old and new adult daily values is provided at Reference Daily Intake.
== Function == The GLP2 receptor (GLP2R) is a G protein-coupled receptor superfamily member closely related to the glucagon receptor (GLP1 receptor). Glucagon-like peptide-2 (GLP2) is a 33-amino acid proglucagon-derived peptide produced by intestinal enteroendocrine cells. Like glucagon-like peptide-1 (GLP1) and glucagon itself, it is derived from the proglucagon peptide encoded by the GCG gene. GLP2 stimulates intestinal growth and upregulates villus height in the small intestine, concomitant with increased crypt cell proliferation and decreased enterocyte apoptosis. Moreover, GLP2 prevents intestinal hypoplasia resulting from total parenteral nutrition. GLP2R, a G protein-coupled receptor superfamily member is expressed in the gut and closely related to the glucagon receptor (GCGR) and the receptor for GLP1 (GLP1R).
== Complications == Vaginal support structures can be damaged or weakened during childbirth or pelvic surgery. Other conditions that repeatedly strain or increase pressure in the pelvic area can also compromise support. Examples are:
Research links regular MDMA use to reduced grey matter volume, particularly in the hippocampus. Structural MRI scans show significant volume reductions in the hippocampus, specifically subregions such as CA1, which directly control memory formation.
Sources: en.wikipedia.org
== Implementation == In one of various embodiments of EWOD-based microfluidic biochips, investigated first by Cytonix in 1987 and subsequently commercialized by Advanced Liquid Logic, there are two parallel glass plates. The bottom plate contains a patterned array of individually controllable electrodes and the top plate is coated with a continuous grounding electrode. A dielectric insulator coated with a hydrophobic is added to the plates to decrease the wet-ability of the surface and to add capacitance between the droplet and the control electrode. The droplet containing biochemical samples and the filler medium, such as the silicone oil, a fluorinated oil, or air, are sandwiched between the plates and the droplets travel inside the filler medium. In order to move a droplet, a control voltage is applied to an electrode adjacent to the droplet, and at the same time, the electrode just under the droplet is deactivated. By varying the electric potential along a linear array of electrodes, electrowetting can be used to move droplets along this line of electrodes.
BRD-6929, also widely known as "compound 60" (Cpd-60 or Cmpd60), is a histone deacetylase (HDAC) inhibitor which is used in scientific research. It has been described in the past as the prototypical selective HDAC1 and HDAC2 inhibitor. However, subsequent findings suggest that BRD-6929 may not actually be selective for HDAC1 and HDAC2 over HDAC3.
25 December – Gull New Zealand and NPD announce plans to merge their New Zealand operations, subject to approval from the Commerce Commission. 29 December — Gale force winds disrupt camping grounds and festivals, down trees and cause power outages in the upper North Island and Buller District in the South Island's West Coast Region. 30 December — Strong winds cause power disruptions to 10,000 homes and at least 50 cellphone towers in the Tasman District. 31 December – The 2026 New Year Honours are announced.
In March 1916 (BR.23–BR.26), Robertson announced the results of a series of experiments that he and his assistant, Louis Adolph Ray, had conducted with the white mice — chosen as his "experimental animal" because of their "hardiness, rapid growth, smallness, and fecundity" (BR.23, p.366) — wherein the oral administration of tethelin, a "growth-controlling principle" (which they later described as "the ether-precipitable fraction of an alcoholic extract of the anterior lobe of the pituitary body"), produced precisely "the same effects on their growth" as those "which [had] accompan[ied] the [oral] administration of the whole tissue of the anterior lobe of the pituitary body" to his control group (BR.25, p.397). As Everitt (AE.2, p.63) notes — having distinguished (p.66) Robertson and Ray's "growth controlling principle" of the pituitary (BR.35) from Moon, et al.'s "growth stimulating principle" (HM.2) — it was not until the (1921) work of Herbert Evans and Joseph Long (HE.1; HE.2) that "[it was] conclusively proved that the pituitary contained a growth-stimulating hormone". Evans and Long also discovered that, whilst the oral administration of their "pituitary principle" had no effect, administration per medium of an intraperitoneal injection was effective: which led them to the conclusion that whatever the pituitary's 'active principle' might be, it was "digested in the alimentary canal".
Robin Harper, a former leader of the Scottish Greens, joins Scottish Labour, citing his former party's failure on the environment for his decision. 12 June – MSPs vote for the early release of 500 prisoners in order to ease overcrowding in the Scottish Prison Service. Edinburgh City Council approves plans by AEG to build an 8,500 capacity stadium at Edinburgh Park. 13 June – Stagecoach Group announces plaans to cut services in north Scotland as it launches a review of its operations. 14 June – Five Scotland fans are taken to hospital after their hire car crashed as they left an airport in Germany driving on the wrong side of the road. The Independent Parliamentary Standards Authority clears Douglas Ross of misusing his travel expenses following an investigation. The 2024 Birthday Honours are published. Among Scots to be recognised are former Prime Minister Gordon Brown, who becomes a Companion of Honour, and footballers Graeme Souness (CBE) and Ally McCoist (MBE). 16 June – Aberdeen City Council cancels the 2024 Highland Games shortly before it is due to commence following "heavier than forecast" rain. 17 June – NHS Dumfries and Galloway warns residents living in the area to assume some of their data has been published online after its database was hacked. 18 June – Scottish Labour launches its general election manifesto. 19 June – The Scottish National Party launches its election manifesto, with plans to "end Westminster cuts" and increase investment in the NHS.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.