If you have been reading about Replicative senescence 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 2026-07-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
== Research and advocacy == The Muscular Dystrophy Association (MDA) is involved in research, advocacy, and services for individuals affected by muscular dystrophy. The organization provides resources that contribute to understanding and addressing this condition.
=== BLT (bone marrow/liver/thymus) model === The BLT model is constituted with human HSCs, bone marrow, liver, and thymus. The engraftment is carried out by implantation of liver and thymus under the kidney capsule and by transplantation of HSCs obtained from fetal liver. The BLT model has a complete and totally functional human immune system with HLA-restricted T lymphocytes. The model also comprises a mucosal system that is similar to that of humans. Moreover, among all models the BLT model has the highest level of human cell reconstitution. However, since it requires surgical implantation, this model is the most difficult and time-consuming to develop. Other drawbacks associated with the model are that it portrays weak immune responses to xenobiotics, sub-optimal class switching and may develop GvHD.
== History == Fosfomycin (originally known as phosphonomycin) was discovered in a joint effort of Merck and Co. and Spain's Compañía Española de Penicilina y Antibióticos (CEPA). It was first isolated by screening broth cultures of Streptomyces fradiae isolated from soil samples for the ability to cause formation of spheroplasts by growing bacteria. The discovery was described in a series of papers published in 1969. CEPA began producing fosfomycin on an industrial scale in 1971 at its Aranjuez facility.
== Nomenclature == A tRNA is commonly named by its intended amino acid (e.g. tRNA-Asn), by its anticodon sequence (e.g. tRNA(GUU)), or by both (e.g. tRNA-Asn(GUU) or tRNAAsnGUU). These two features describe the main function of the tRNA, but do not actually cover the whole diversity of tRNA variation; as a result, numerical suffixes are added to differentiate. tRNAs intended for the same amino acid are called "isotypes"; when isotypes also share the same anticodon they are called "isoacceptors"; and when isotypes have an identical mature sequence they are called "isodecoders".
Sources: en.wikipedia.org
Apart from several bog bodies, Denmark has also yielded several other mummies, such as the three Borum Eshøj mummies, the Skrydstrup Woman and the Egtved Girl, who were all found inside burial mounds, or tumuli. In 1875, the Borum Eshøj grave mound was uncovered, which had been built around three coffins, which belonged to a middle aged man and woman as well as a man in his early twenties. Through examination, the woman was discovered to be around 50–60 years old. She was found with several artifacts made of bronze, consisting of buttons, a belt plate, and rings, showing she was of higher class. All of the hair had been removed from the skull later when farmers had dug through the casket. Her original hairstyle is unknown. The two men wore kilts, and the younger man wore a sheath which contained a bronze dagger. All three mummies were dated to 1351–1345 BC. The Skrydstrup Woman was unearthed from a tumulus in Southern Jutland, in 1935. Carbon-14 dating showed that she had died around 1300 BC; examination also revealed that she was around 18–19 years old at the time of death, and that she had been buried in the summertime. Her hair had been drawn up in an elaborate hairstyle, which was then covered by a horse hair hairnet made by the sprang technique. She was wearing a blouse and a necklace as well as two golden earrings, showing she was of higher class. The Egtved Girl, dated to 1370 BC, was also found inside a sealed coffin within a tumulus, in 1921. She was wearing a bodice and a skirt, including a belt and bronze bracelets.
The first step in testing a new treatment in humans. These studies test the best way to give a new treatment (for example, by mouth, intravenous infusion, or injection) and the best dose. The dose is usually increased a little at a time in order to find the highest dose that does not cause harmful side effects. Because little is known about the possible risks and benefits of the treatments being tested, phase I trials usually include only a small number of patients who have not been helped by other treatments. (NCI) Initial studies to determine the metabolism and pharmacologic actions of drugs in humans, the side effects associated with increasing doses, and to gain early evidence of effectiveness; may include healthy participants and/or patients. (NLM) Phase 1 includes the initial introduction of an investigational new drug into humans. Phase 1 studies are typically closely monitored and may be conducted in patients or normal volunteer subjects. These studies are designed to determine the metabolism and pharmacologic actions of the drug in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on effectiveness. During Phase 1, sufficient information about the drug's pharmacokinetics and pharmacological effects should be obtained to permit the design of well-controlled, scientifically valid, Phase 2 studies. The total number of subjects and patients included in Phase 1 studies varies with the drug, but is generally in the range of 20 to 80.
A 100-gram reference quantity of raw soybeans supplies 1,866 kilojoules (446 kilocalories) of food energy and are 9% water, 30% carbohydrates, 20% total fat and 36% protein. Peanuts are the only legumes with a higher fat content (48%) and calorie count (2,385 kJ). They contain less carbohydrates (21%), protein (25%) and dietary fiber (9%). Soybeans are a rich source of essential nutrients, providing in a 100-gram serving (raw, for reference) high contents of the Daily Value (DV) especially for protein (36% DV), dietary fiber (37%), iron (121%), manganese (120%), phosphorus (101%) and several B vitamins, including folate (94%) (table). High contents also exist for vitamin K, magnesium, zinc and potassium. For human consumption, soybeans must be processed prior to consumption–either by cooking, roasting, or fermenting–to destroy the trypsin inhibitors (serine protease inhibitors). Raw soybeans, including the immature green form, are toxic to all monogastric animals.
Maximum levels for baby foods and chocolate/cocoa products were established under Commission Regulation (EU) No 488/2014. 1986 California Proposition 65 requires a warning label on chocolate products having more than 4.1 mg of cadmium per daily serving of a single product.
On successful completion of Module D, the Officer Cadets receive their Commission and become Second Lieutenants. Further training that is required prior to them being considered for operational deployment and promotion to Lieutenant includes: Post Commissioning Training (formerly known as Module 5), again run at an OTC, over 3 weekends. Special To Arm training is specific to the type of unit the Subaltern is joining and covers a 2-week period. This is increasingly integrated with the tactics phase of a Regular training course. For example, the Platoon Commander's Battle Course held at the Infantry Battle School in Brecon, which is integrated within a Regular training course, or the Light Cavalry Commander's Course held at the Reconnaissance & Armoured Tactics Division in Warminster, which is run separately to Regular training courses.
Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
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.