A practical reference on AEDG tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-27 and is reviewed periodically as new material appears.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Compound class | Synthetic tetrapeptide | Not a natural free peptide |
| Research origin | Russian gerontology institutes | Developed during the 1990s |
| Main research claim | Telomerase activation | Evidence mainly from cultured cells |
| Regulatory status | Not an approved drug | Handled as a research material |
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
Remains may be exhumed and reburied en masse when a cemetery is relocated, once local planning and religious requirements are met. It also enables construction agencies to clear the way for new constructions. One example of this is cemeteries in Chicago next to O'Hare International Airport to expand the runways. The remains of the Venerable or the Blessed are sometimes exhumed to ensure their bodies lie in their correctly marked graves, as their gravesites usually become places for devotees to gather, and also to collect relics. The bodies may also be transferred to a more dignified place. It also serves the purpose to see if they are supernaturally Incorrupt. An incorrupt corpse is no longer considered miraculous, but it is a characteristic of several known saints. Exhumation is no longer a requirement in the beatification process, but still may be carried out. For ethical and cultural reasons, repatriation and reburial of human remains may be carried out when museums and academic institutions return remains to their place of origin.
Intensive insulin therapy or flexible insulin therapy is a therapeutic regimen for diabetes mellitus treatment. This newer approach contrasts with conventional insulin therapy. Rather than minimize the number of insulin injections per day (a technique which demands a rigid schedule for food and activities), the intensive approach favors flexible meal times with variable carbohydrate as well as flexible physical activities. The trade-off is the increase from 2 or 3 injections per day to 4 or more injections per day, which was considered "intensive" relative to the older approach. In North America in 2004, many endocrinologists prefer the term "flexible insulin therapy" (FIT) to "intensive therapy" and use it to refer to any method of replacing insulin that attempts to mimic the pattern of small continuous basal insulin secretion of a working pancreas combined with larger insulin secretions at mealtimes. The semantic distinction reflects changing treatment.
=== Reactions of strained alkenes === Strained alkenes also use strain-relief as a driving force that allows for their participation in click reactions. Trans-cycloalkenes (usually cyclooctenes) and other strained alkenes such as oxanorbornadiene react in click reactions with a number of partners including azides, tetrazines, and tetrazoles. These reaction partners may interact specifically with the strained alkene, staying bioorthogonal to endogenous alkenes found in lipids, fatty acids, cofactors, and other natural products.
In 1939, the Soviet Union and Nazi Germany agreed to the Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics (Molotov–Ribbentrop Pact, 23 August 1939) and to jointly invade and partition Poland, by way of which Nazi Germany started the Second World War (1 September 1939). In the 1941–1942 period of the Great Patriotic War, the German invasion of the Soviet Union (Operation Barbarossa, 22 June 1941) was ineffectively opposed by the Red Army, who were poorly led, ill-trained and under-equipped. As a result, they fought poorly and suffered great losses of soldiers (killed, wounded and captured). The weakness of the Red Army was partly consequence of the Great Purge (1936–1938) of senior officers and career soldiers whom Stalin considered politically unreliable. Strategically, the Wehrmacht's extensive and effective attack threatened the territorial integrity of the Soviet Union and the political integrity of Stalin's model of a communist state, when the Nazis were initially welcomed as liberators by the anti-communist and nationalist populations in the Byelorussian Soviet Socialist Republic, the Georgian Soviet Socialist Republic and the Ukrainian Soviet Socialist Republic. The anti-Soviet nationalists' collaboration with the Nazi's lasted until the Schutzstaffel and the Einsatzgruppen began their Lebensraum killings of the Jewish populations, the local communists, the civil and community leaders—the Holocaust meant to realise the Nazi German colonisation of Bolshevik Russia.
Sources: en.wikipedia.org
=== Primary cold agglutinin disease === In single-center series, primary CAD has been found to account for 13–15% of the cases of AIHA. In a population-based clinical study of primary CAD in Norway, the prevalence was found to be 16 per million in habitants and the incidence rate 1 per million inhabitants per year. Little is known about possible geographic variations. Median age of CAD patients was 76 years and median age at onset of symptoms was approximately 67 years. The male/female ratio has been reported to be 0.5–0.6 which is not very different from a male/female ratio of 0.72 in an age-matched general population. The frequency of auto-immune disorders other than CAD does probably not differ from what is to be expected in an elderly population with some female predominance. as about 12.5 years from diagnosis and median age at death was 82 years, which implies a life expectancy in these patients similar to that of an age-matched general population. More than 90% of patients with primary CAD have Cold-induced circulatory symptoms ranging from moderate acrocyanosis to severe Raynaud phenomena precipitated even by very slight cold exposure.
This steroid hormone acts on the epithelial cells of the upper small intestine, increasing their capacity to absorb calcium from the gut contents into the blood. The second homeostatic mechanism, with its sensors in the thyroid gland, releases calcitonin into the blood when the blood ionized calcium rises. This hormone acts primarily on bone, causing the rapid removal of calcium from the blood and depositing it, in insoluble form, in the bones. The two homeostatic mechanisms working through PTH on the one hand, and calcitonin on the other can very rapidly correct any impending error in the plasma ionized calcium level by either removing calcium from the blood and depositing it in the skeleton, or by removing calcium from it. The skeleton acts as an extremely large calcium store (about 1 kg) compared with the plasma calcium store (about 180 mg). Longer term regulation occurs through calcium absorption or loss from the gut. Another example are the most well-characterised endocannabinoids like anandamide (N-arachidonoylethanolamide; AEA) and 2-arachidonoylglycerol (2-AG), whose synthesis occurs through the action of a series of intracellular enzymes activated in response to a rise in intracellular calcium levels to introduce homeostasis and prevention of tumor development through putative protective mechanisms that prevent cell growth and migration by activation of CB1 and/or CB2 and adjoining receptors.
==== Rivaroxaban ==== Rivaroxaban chemically belongs to the group of n-aryloxazolidinones. Other drugs of that group are linezolid and tedizolid, both of whom are antibiotics. A synthesis of n-aryloxazolidinones starting with an O-silyl protected ethyl(2,3-dihydroxypropyl)-carbamate was published in 2016. In a one-pot reaction the carbamate cyclisizes to a 2-oxazolidone ring under slightly basic conditions while simultaneously the oxazolidone nitrogen is arylized by copper-catalization. For rivaroxaban in particular, 3-morpholinone substitutes the iodine in p-position of the benzene ring by copper-catalization. Afterwards, the silyl protecting group is removed and the resulting alcohol is replaced by an amino group which is then acylated in the last step. An industrial preparation of rivaroxaban was registered as a patent by Bayer Healthcare in 2005. It starts from N-(4-aminophenol)-morpholinone which is alkylated by a propylene oxide derivate that also contains a primary amine involved in a phthalimide protection group. Next, a phosgene equivalent is added to form the 2-oxazolidone ring and the phthalimide is removed. The free amine can now be acylated which leads to rivaroxaban. However, according to the patent the synthesis has “various disadvantages in the reaction management which has particularly unfavourable effects for preparation“. The patent also explains another synthesis starting from a chlorothiophene derivate that would be more suitable for the industrial process but points out that toxic solvents or reagents have to be removed from the final product.
Sources: en.wikipedia.org
Chloral hydrate is a geminal diol with the formula Cl3C−CH(OH)2. It was first used as a sedative and hypnotic in Germany in the 1870s. Over time it was replaced by safer and more effective alternatives but it remained in use in the United States until at least the 1970s. It sometimes finds usage as a laboratory chemical reagent and precursor. It is derived from chloral (trichloroacetaldehyde) by the addition of one equivalent of water.
Chemistry... Key to Better Living. Diamond Jubilee Volume: A Record of Chemical Progress During the First 75 Years of the American Chemical Society. American Chemical Society. 1951. Skolnik, Herman; Reese, Kenneth M., eds. (1976). A Century of chemistry: the role of chemists and the American Chemical Society. Washington, D.C.: American Chemical Society. ISBN 978-0841203075. J. J. Bohning 2001. American Chemical Society Founded 1876. ACS, Washington, D.C. Reese, Kenneth M., ed. (2002). The American Chemical Society at 125: A recent history 1976–2001. American Chemical Society. ISBN 978-0-8412-3851-0. ACS website ACS Publications website ACS Chemical & Engineering News ACS Chemical Abstracts Service (CAS) International Year of Chemistry 2011(archived) A Cauldron Bubbles: PubChem and the American Chemical Society — Information Today, June 2005 ACS Chemical Biology WIKI(archived) ACS Chemical Biology Community(archived) ACS Green Chemistry Institute ACS Organic Division Leete Award Gassman Award
Team Fortress Classic is a 1999 first-person shooter game developed by Valve and published by Sierra Studios. It was originally released in April 1999 as a mod for Valve's 1998 Windows game Half-Life, and is based on Team Fortress, a mod for the 1996 game Quake. In Team Fortress Classic, two teams compete in online multiplayer matches. Players choose one of nine classes, each with different skills. The scenarios include capture the flag, territorial control, and escorting a "VIP" player. Valve hired the developers of the Team Fortress mod to develop Team Fortress Classic. It received generally positive reviews, although the graphics were a point for criticism. In 2000, Valve released a standalone version, Team Fortress 1.5, with new character models, maps and other features. Team Fortress 2 was released in 2007.
== Adverse effects == In about 0.1% of cases people have had anaphylactic reactions to lixisenatide and in about 0.2% of cases the drug has caused pancreatitis. Use with insulin or sulfonylurea may cause hypoglycemia. In some cases, people with no kidney disease have had acute kidney injury and in some people with existing kidney disease the condition has gotten worse. Because lixisenatide is a peptide people can and do develop an immune response to it that will eventually make the drug ineffective; people who have developed antibodies to lixisenatide tend to have more inflammation at the injection site. At least 5% of people had nausea, vomiting, diarrhea, headache, or dizziness after taking lixisenatide.
Sources: en.wikipedia.org
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.
That question is not settled. Cell culture studies have reported increased telomerase activity after treatment, but comparable evidence from controlled human trials is lacking. Any claim about telomere lengthening in people should be treated as unproven.
It has not completed the large, controlled trials required for drug approval in major jurisdictions. Most human reports involve small samples and limited follow-up. As a result, it is sold as a research chemical rather than a licensed pharmaceutical product.
It is a synthetic tetrapeptide built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.