If you have been reading about Khavinson 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 2026-04-23. 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.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
| 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 proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
Menthol's ability to chemically trigger the cold-sensitive TRPM8 receptors in the skin is responsible for the well-known cooling sensation it provokes when inhaled, eaten, or applied to the skin. In this sense, it is similar to capsaicin, the chemical responsible for the spiciness of hot chilis (which stimulates heat sensors, also without causing an actual change in temperature). Menthol's analgesic properties are mediated through a selective activation of κ-opioid receptors. Menthol blocks calcium channels and voltage-sensitive sodium channels, reducing neural activity that may stimulate muscles. Some studies show that menthol acts as a GABAA receptor positive allosteric modulator and increases GABAergic transmission in PAG neurons. Menthol has anesthetic properties similar to, though less potent than, propofol because it interacts with the same sites on the GABAA receptor. Menthol may also enhance the activity of glycine receptors and negatively modulate 5-HT3 receptors and nAChRs. Menthol is widely used in dental care as a topical antibacterial agent, effective against several types of streptococci and lactobacilli. Menthol also lowers blood pressure and antagonizes vasoconstriction through TRPM8 activation. Menthol inhalation was demonstrated to improve cognitive decline in Alzheimer's disease mouse models. It also produced immunostimulatory effects in the mice.
== Adverse effects == Products containing lisdexamphetamine have a comparable drug safety profile to those containing amphetamine. The major side effects of lisdexamphetamine in short-term clinical trials (≥5% incidence) have included decreased appetite, insomnia, dry mouth, weight loss, irritability, upper abdominal pain, nausea, vomiting, diarrhea, constipation, increased heart rate, anxiety, dizziness, and feeling jittery. Rates of side effects may vary in adults, adolescents, and children. Rare but serious side effects of lisdexamphetamine may include mania, sudden cardiac death in those with underlying heart problems, stimulant psychosis, and serotonin syndrome.
The maximum life span of transgenic mice has been extended about 20% by overexpression of human catalase targeted to mitochondria A comparison of 7 non-primate mammals (mouse, hamster, rat, guinea-pig, rabbit, pig and cow) showed that the rate of mitochondrial superoxide and hydrogen peroxide production in heart and kidney were inversely correlated with maximum life span A study of 8 non-primate mammals showed an inverse correlation between maximum life span and oxidative damage to mtDNA (mitochondrial DNA) in heart & brain A study of several species of mammals and a bird (pigeon) indicated a linear relationship between oxidative damage to protein and maximum life span There is a direct correlation between DNA repair and maximum life span for mammalian species Drosophila (fruit-flies) bred for 15 generations by only using eggs that were laid toward the end of reproductive life achieved maximum life spans 30% greater than that of controls Overexpression of the enzyme which synthesizes glutathione in long-lived transgenic Drosophila (fruit-flies) extended maximum lifespan by nearly 50% A mutation in the age−1 gene of the nematode worm Caenorhabditis elegans increased mean life span 65% and maximum life span 110%. However, the degree of lifespan extension in relative terms by both the age-1 and daf-2 mutations is strongly dependent on ambient temperature, with ≈10% extension at 16 °C and 65% extension at 27 °C. Fat-specific Insulin Receptor KnockOut (FIRKO) mice have reduced fat mass, normal calorie intake and an increased maximum life span of 18%.
According to Analayo, each of the twelve nidanas "re-quires all five aggregates to be in existence concurrently." Furthermore:The teaching on dependent arising does not posit the existence of any of the links in the abstract, but instead show how a particular link, as an aspect of the continuity of the five aggregates, has a conditioning influence on another link. It does not imply that any of these links exist apart from the five aggregates.
Sources: en.wikipedia.org
AAA proteases use the energy from ATP hydrolysis to translocate a protein inside the proteasome for degradation. Cdc48p/p97 functions as a hexameric AAA+ ATPase that provides the mechanical force necessary for substrate dislocation. Its activity is tightly regulated by ATP binding and hydrolysis, which induce conformational changes required for protein unfolding and extraction. The HbYX motif plays a crucial role in regulating this process by mediating interactions between Cdc48p/p97 and downstream effectors such as the 20S proteasome or specific cofactors (e.g., Ufd1/Npl4). This interaction facilitates substrate transfer from Cdc48p/p97 to the proteasome, ensuring efficient protein degradation. Given its pivotal role in protein homeostasis, Cdc48p/p97 has been implicated in a wide range of cellular processes beyond ERAD, including autophagy, mitochondrial quality control, and DNA repair. The dysregulation of its function, particularly through mutations affecting the ATPase domain or HbYX-mediated interactions, has been linked to neurodegenerative diseases and cancer.
Technetium exits the generator in the form of the pertechnetate ion, TcO4−. The oxidation state of Tc in this compound is +7. This is directly suitable for medical applications only in bone scans (it is taken up by osteoblasts) and some thyroid scans (it is taken up in place of iodine by normal thyroid tissues). In other types of scans relying on 99mTc, a reducing agent is added to the pertechnetate solution to bring the oxidation state of the technecium down to +3 or +4. Secondly, a ligand is added to form a coordination complex. The ligand is chosen to have an affinity for the specific organ to be targeted. For example, the exametazime complex of Tc in oxidation state +3 is able to cross the blood–brain barrier and flow through the vessels in the brain for cerebral blood flow imaging. Other ligands include sestamibi for myocardial perfusion imaging and mercapto acetyl triglycine for MAG3 scan to measure renal function.
=== Dosage units === One international unit of insulin (1 IU) is defined as the "biological equivalent" of 34.7 μg pure crystalline insulin. The first definition of a unit of insulin was the amount required to induce hypoglycemia in a rabbit. This was set by James Collip at the University of Toronto in 1922. Of course, this was dependent on the size and diet of the rabbits. The unit of insulin was set by the insulin committee at the University of Toronto. The unit evolved eventually to the old USP insulin unit, where one unit (U) of insulin was set equal to the amount of insulin required to reduce the concentration of blood glucose in a fasting rabbit to 45 m g/d L (2.5 m mol/L). Once the chemical structure and mass of insulin was known, the unit of insulin was defined by the mass of pure crystalline insulin required to obtain the USP unit. The unit of measurement used in insulin therapy is not part of the International System of Units (abbreviated SI) which is the modern form of the metric system. Instead the pharmacological international unit (IU) is defined by the WHO Expert Committee on Biological Standardization.
=== Carbon metabolism === Clostridium scindens can anaerobically ferment several different carbon sources, including monosaccharides (fructose, galactose, glucose, mannose, ribose, and xylose), a disaccharide (lactose), and a couple of 2-sugar alcohols (dulcitol and sorbitol). Glucose metabolism takes the form of mixed acid fermentation, as the fermentation products include acetate, ethanol, and formate. In defined and minimal media, the preferred glucose fermentation product for C. scindens is ethanol, while the production of hydrogen, acetate, and formate significantly decreases during growth in minimal media.
=== Iminodisuccinic acid (IDS) === Commercially used since 1998, iminodisuccinic acid (IDS) biodegrades by about 80% after only 7 days. IDS binds to calcium exceptionally well and forms stable compounds with other heavy metal ions. In addition to having a lower toxicity after chelation, IDS is degraded by Agrobacterium tumefaciens (BY6), which can be harvested on a large scale. The enzymes involved, IDS epimerase and C−N lyase, do not require any cofactors.
Sources: en.wikipedia.org
Following settlement in northward regions of Asia and Europe which seasonally get less sunlight, the selective pressure for radiation-protective skin tone decreased while a need for efficient vitamin D synthesis in skin increased, resulting in low-melanin, lighter skin tones in the rest of the prehistoric world. For people with low skin melanin, moderate sun exposure to the face, arms and lower legs several times a week is sufficient. However, for recent cultural changes such as indoor living and working, UV-blocking skin products to reduce the risk of sunburn and emigration of dark-skinned people to countries far from the equator have all contributed to an increased incidence of vitamin D insufficiency and deficiency that need to be addressed by food fortification and vitamin D dietary supplements.
Surgeons performing an amputation have to first ligate the supplying artery and vein, so as to prevent hemorrhage (bleeding). The muscles are transected, and finally, the bone is sawed through with an oscillating saw. Sharp and rough edges of bones are filed, and skin and muscle flaps are then transposed over the stump, occasionally with the insertion of elements to attach a prosthesis.
The first consignment of dressed beef left the Chicago stock yards in 1857 in ordinary boxcars retrofitted with bins filled with ice. Placing meat directly against ice resulted in discoloration and affected the taste, making it impractical. During the same period, Gustavus Swift experimented by moving cut meat using a string of ten boxcars with their doors removed, and made a few test shipments to New York during the winter months over the Grand Trunk Railway (GTR). The method proved too limited to be practical. Detroit's William Davis patented a refrigerator car that employed metal racks to suspend the carcasses above a frozen mixture of ice and salt. In 1868, he sold the design to George H. Hammond, a Detroit meatpacker, who built a set of cars to transport his products to Boston, using ice from the Great Lakes for cooling. The load tended to swing to one side when the car entered a curve at high speed, and use of the units was discontinued after several derailments. In 1878, Swift hired engineer Andrew Chase to design a ventilated, well-insulated car and positioned the ice in a compartment at the top of the car, allowing the chilled air to flow naturally downward. The meat was packed tightly at the bottom of the car to keep the center of gravity low and to prevent the cargo from shifting. Chase's design proved to be a practical solution, providing temperature-controlled carriage of dressed meats. This allowed Swift and Company to ship their products across the United States and internationally.
=== Micro-mechanical cleavage === The most famous, clean and rather straightforward method of isolating graphene sheets, called micro-mechanical cleavage or more colloquially called the scotch tape method, was introduced by Novoselov et al. in 2004, which uses adhesive tape to mechanically cleave high-quality graphite crystals into successively thinner platelets. Other methods do exist like exfoliation.
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.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.