Everything below concerns shelf life. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-21. Numbers and descriptions here follow the published literature rather than marketing material.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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.
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.
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.
=== Hemoglobin A1c === Hemoglobin A1c is a measure of the percent of red blood cells that are glycated, or have a glucose molecule attached. This can be used as an indicator of blood glucose level over a longer period of time and is often used to diagnose prediabetes as well as diabetes. HbA1c may not accurately represent blood glucose levels and should not be used in certain medical conditions such as iron-deficiency anemia, Vitamin B12 and folate deficiency, pregnancy, hemolytic anemia, an enlarged spleen, and end-stage kidney failure.
=== Intracellular transport === Little is known about intracellular kinetics of thyroid hormones. However, recently it could be demonstrated that the crystallin CRYM binds 3,5,3′-triiodothyronine in vivo.
=== Treatment options for antiviral resistant pathogens === If a virus is not fully wiped out during a regimen of antivirals, treatment creates a bottleneck in the viral population that selects for resistance, and there is a chance that a resistant strain may repopulate the host. Viral treatment mechanisms must therefore account for the selection of resistant viruses. The most commonly used method for treating resistant viruses is combination therapy, which uses multiple antivirals in one treatment regimen. This is thought to decrease the likelihood that one mutation could cause antiviral resistance, as the antivirals in the cocktail target different stages of the viral life cycle. This is frequently used in retroviruses like HIV, but a number of studies have demonstrated its effectiveness against influenza A, as well. Viruses can also be screened for resistance to drugs before treatment is started. This minimizes exposure to unnecessary antivirals and ensures that an effective medication is being used. This may improve patient outcomes and could help detect new resistance mutations during routine scanning for known mutants. However, this has not been consistently implemented in treatment facilities at this time. The new potential approach is the combination of DAA and HTA which create a genetic barrier against mutations.
Lavín, José L; Kiil, Kristoffer; Resano, Ohiana; Ussery, David W; Oguiza, José A (2007). "Comparative genomic analysis of two-component regulatory proteins in Pseudomonas syringae". BMC Genomics. 8 397. doi:10.1186/1471-2164-8-397. PMC 2222644. PMID 17971244. Type strain of Pseudomonas syringae at BacDive – the Bacterial Diversity Metadatabase
=== Humanitarian work === Collins is a supporter of animal rights. She has appeared in numerous campaigns for the animal rights organisation PETA. In 2013, she posed naked for the "I'd Rather Go Naked Than Wear Fur" campaign. In 2020, Collins was photographed in a bathtub to highlight the fact that marine animals are separated from their families and confined to concrete tanks. In 2021, she posed with a skinned fox as she backed the campaign to end the fur trade in the United Kingdom. Addressing then prime minister Boris Johnson, Collins said "Take it from an icon, Boris – no one needs fur in their wardrobe. Do the right thing – ban fur imports and sales. Let's wear our skin and let the animals keep theirs." Speaking on her podcast, Collins expressed her interest in becoming a humanitarian and said she wishes to promote conservation and animal welfare to the next generation. In November 2022, Collins opened a newly refurbished Cats Protection adoption centre in Chelmsford, during which she was given a tour and the opportunity to name one of the cats, which she named after Mr. Mistoffelees from Cats. Following the re-opening, Collins said she was "putting out a plea to help these amazing people give cats a home". In March 2023, Collins assisted with the launch of the Be A Cat Cafe in Soho, a pop-up experience from cat food brand Felix. Attending the event, Collins said "I'm here for cattitude and think that if people tried being more like a cat, they'd be a lot more chilled out and relaxed".
Sources: en.wikipedia.org
== Materials and techniques == In the late 1990s, with the huge popularity of surgical rejuvenation and the concomitant increase of cosmetic surgery procedures worldwide, more substances, along with biocompatible materials commonly used in other medical applications for years, became available to surgeons for use in augmenting thinning or misshapen lips into more plump and attractive features. Some of the first widely used lip augmentation substances were:
== External links == Anatomy photo: TermsCells&Tissues/connective/reticular/reticular1 - Comparative Organology at University of California, Davis - "Connective tissue, reticular (LM, Medium)" Histology at uwa.edu.au
In such a situation the risk for another affected child is higher than in a genotypically normal parent. Type III collagen could also be important in several other human diseases. Increased amounts of type III collagen are found in many fibrotic conditions such as liver and kidney fibrosis, and systemic sclerosis. This has led to a search for serum biomarkers that could be used for diagnosing these conditions without having to obtain a tissue biopsy. The most widely used biomarker is the N-terminal propeptide of type III procollagen, which is cleaved off during the biosynthesis of type III collagen.
==== Keratan sulfate ==== Keratan sulfates have a variable sulfate content and, unlike many other GAGs, do not contain uronic acid. They are present in the cornea, cartilage, bones, and the horns of animals.
Sources: en.wikipedia.org
== History == Insulin lispro (brand name Humalog) was granted marketing authorization in the European Union in April 1996, and it was approved for use in the United States in June 1996. Insulin lispro (brand name Liprolog) was granted marketing authorization in the European Union in May 1997, and again in August 2001. Combination drugs combining insulin lispro and other forms of insulin were approved for use in the United States in December 1999. Insulin lispro Sanofi was granted marketing authorization as a biosimilar in the European Union in July 2017. Insulin lispro injection (brand name Admelog) was approved for use in the United States in December 2017. In January 2020, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency recommended granting of a marketing authorization for insulin lispro acid (brand name Lyumjev) for the treatment of diabetes in adults. Insulin lispro (Lyumjev) was approved for use in the European Union in March 2020, and in the United States in June 2020.
As an antagonist at ionotropic AMPA, NMDA and Kainate glutamate receptors in the concentration range of 0.1-2.5 mM. As a noncompetitive antagonist at the glycine site of the NMDA receptor. As an antagonist of the α7 nicotinic acetylcholine receptor. However, recently (2011) direct recording of α7 nicotinic acetylcholine receptor currents in adult (noncultured) hippocampal interneurons by the Cooper laboratory validated a 2009 study that failed to find any blocking effect of kynurenic acid across a wide range of concentrations, thus suggesting that in noncultured, intact preparations from adult animals there is no effect of kynurenic acid on α7 nicotinic acetylcholine receptor currents. As a ligand for the orphan G protein-coupled receptor GPR35. As an agonist for the G protein-coupled receptor HCAR3.
=== Ion Exchange Chromatography === Ion exchange chromatography separates proteins based on their net charge at a given pH. The stationary phase consists of charged resin beads that interact with oppositely charged proteins. As the sample passes through the column, proteins bind to the resin while unbound proteins are washed away. By gradually changing the ionic strength or pH of the elution buffer, bound proteins can be released in a controlled manner, allowing for effective separation.
A herpetarium is a zoological exhibition space for reptiles and amphibians. In the Western world, some snakes (especially relatively docile species such as the ball python and corn snake) are sometimes kept as pets. Numerous species of lizard are kept as pets, including bearded dragons, iguanas, anoles, and geckos (such as the popular leopard gecko and the crested gecko). Turtles and tortoises are increasingly popular pets, but keeping them can be challenging due to their particular requirements, such as temperature control, the need for UV light sources, and a varied diet. The long lifespans of turtles and especially tortoises mean they can potentially outlive their owners. Good hygiene and significant maintenance is necessary when keeping reptiles, due to the risks of Salmonella and other pathogens. Regular hand-washing after handling is an important measure to prevent infection.
== Role in cancer == IRS-1, as a signalling adapter protein, is able to integrate different signalling cascades, which indicates its possible role in cancer progression. IRS-1 protein is known to be involved in various types of cancer, including colorectal, lung, prostate and breast cancer. IRS-1 integrates signalling from insulin receptor (InsR), insulin-like growth factor-1 receptor (IGF1R) and many other cytokine receptors and is elevated in β-catenin induced cells. Some evidence shows that TCF/LEF-β-catenin complexes directly regulate IRS-1. IRS-1 is required for maintenance of neoplasmic phenotype in adenomatous polyposis coli (APC) - mutated cells, it is also needed for transformation in ectopically expressing oncogenic β-catenin cells. IRS-1 dominant-negative mutant functions as tumor suppressor, whereas ectopic IRS-1 stimulates oncogenic transformation. IRS-1 is upregulated in colorectal cancers (CRC) with elevated levels of β-catenin, c-MYC, InsRβ and IGF1R. IRS-1 promotes CRC metastasis to the liver. Decreased apoptosis of crypt stem cells is associated with colon cancer risk. Reduced expression of IRS-1 in Apc (min/+) mutated mice shows increased irradiation-induced apoptosis in crypt. Deficiency in IRS-1 - partial (+/-) or absolute (-/-) - in Apc (min/+) mice demonstrates reduced amount of tumors comparing to IRS-1 (+/+)/ Apc (min/+) mice. In lung adenocarcinoma cell line A549 overexpression of IRS-1 leads to reduced growth. Tumor infiltrating neutrophils have recently been thought to adjust tumor growth and invasiveness.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
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.