epitalon 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.
Last reviewed on 2025-08-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Synthetic tetrapeptide, four residues |
| Nominal mass | Approximately 390 Da | Free peptide; salt forms differ |
| Appearance | White to off-white powder | Commonly supplied lyophilised |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffer |
| Typical storage | −20 °C, desiccated | Cold packs used during transport |
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
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.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
==== Prevalence of medical diagnosis ==== In a study published in 2016, based on US health insurance claims data, out of 19,833,939 US males aged ≥18 years, only 1,108,842 (5.6%), were medically diagnosed with erectile dysfunction or on a PDE5I prescription (μ age 55.2 years, σ 11.2 years). Prevalence of diagnosis or prescription was the highest for age group 60–69 at 11.5%, lowest for age group 18–29 at 0.4%, and 2.1% for 30–39, 5.7% for 40–49, 10% for 50–59, 11% for 70–79, 4.6% for 80–89, 0.9% for ≥90, respectively.
== Speech at LMU Munich (2017) == In a speech marking the 20th anniversary of the Chair of Jewish History and Culture at LMU Munich, Kermani spoke about his feelings during a visit to the Auschwitz concentration camp memorial site and about how living and working in the German language entails a sense of responsibility for the crimes of World War II.
=== Dry skin === Dry skin does not have enough moisture. It will show signs like flaking, tightness, roughness, redness, or cracks. If the skin is very dry, it might also look swollen or extra soft. Common areas that get dry include the face, scalp, and back—especially when exposed to air or clothing. However, places where the skin folds, like under the arms, between the toes, and around the groin, usually do not get as dry. Washing dry skin should be done daily using lukewarm water (less than 37 °C (99 °F)). Avoid long or frequent baths and showers. Try to keep bath time under five minutes per day. If the skin is extremely dry, avoid using regular soap and water, as they can make dryness worse. Instead, use gentle, alkali-free cleansers with a pH of 4 to 5, especially ones with ingredients like urea, lactic acid, or glycerin, which help keep moisture in. Moisturizing dry skin at least twice a day is important. If the skin is very dry, moisturizing more often may help. Thicker, oil-based creams work best for very dry skin. Aqueous cream should be avoided. It also helps to apply a skin protectant. Using a moisturizer with niacinamide and glycerin twice a day has been shown to strengthen the skin and reduce dryness, versus moisturizers without niacinamide.
Nevertheless, the successful synthesis of superheavy elements up to Z = 118 (oganesson) with up to 177 neutrons demonstrates a slight stabilizing effect around elements 110 to 114 that may continue in heavier isotopes, consistent with the existence of the island of stability.
Sources: en.wikipedia.org
In the oil and gas industry, polyacrylamide derivatives (especially co-polymers) have a substantial effect on production by enhanced oil recovery by viscosity enhancement. High viscosity aqueous solutions can be generated with low concentrations of polyacrylamide polymers, which are injected to improve the economics of conventional water-flooding. In a separate application, hydraulic fracturing benefits from drag reduction resulting from injection of these solutions. These applications use large volumes of polymer solutions at concentration of 30–3000 mg/L.
== Chemical synthesis == In 1964, a team of scientists led by Robert B. Woodward elucidated the structure of tetrodotoxin. The structure was confirmed by X-ray crystallography in 1970. Yoshito Kishi and coworkers reported the first total synthesis of racemic tetrodotoxin in 1972. M. Isobe and coworkers and J. Du Bois reported the asymmetric total synthesis of tetrodotoxin in 2003. The two 2003 syntheses used very different strategies, with Isobe's route based on a Diels-Alder approach and Du Bois's work using C–H bond activation. Since then, methods have rapidly advanced, with several new strategies for the synthesis of tetrodotoxin having been developed.
Methods have been developed to purify DNA from organisms, such as phenol-chloroform extraction, and to manipulate it in the laboratory, such as restriction digests and the polymerase chain reaction. Modern biology and biochemistry make intensive use of these techniques in recombinant DNA technology. Recombinant DNA is a man-made DNA sequence that has been assembled from other DNA sequences. They can be transformed into organisms in the form of plasmids or in the appropriate format, by using a viral vector. The genetically modified organisms produced can be used to produce products such as recombinant proteins, used in medical research, or be grown in agriculture.
A notable excision was the removal of the Glen Grey and Herschel Districts, and their allocation to the newly independent Transkei, with the populations of the districts moving into the rest of Ciskei to retain their South African citizenship (which was subsequently lost when Ciskei became independent). By the 1970s, the South African government decided on the final boundaries of Ciskei, as a consolidated area, through the amalgamation of existing reserves allocated to Ciskei, and the purchase of intervening white-owned land. This amalgamation reduced the total length of Ciskei's borders, making them easier for the South African government to police, as well being an attempt to create a more viable area for the homeland.
== Development == For over 150 years, scientists from all around the world have known about the crystallization of protein molecules. In 1840, Friedrich Ludwig Hünefeld accidentally discovered the formation of crystalline material in samples of earthworm blood held under two glass slides and occasionally observed small plate-like crystals in desiccated swine or human blood samples. These crystals were named as 'haemoglobin', by Felix Hoppe-Seyler in 1864. The seminal findings of Hünefeld inspired many scientists in the future. In 1851, Otto Funke described the process of producing human haemoglobin crystals by diluting red blood cells with solvents, such as pure water, alcohol or ether, followed by slow evaporation of the solvent from the protein solution. In 1871, William T. Preyer, Professor at University of Jena, published a book entitled Die Blutkrystalle (The Crystals of Blood), reviewing the features of haemoglobin crystals from around 50 species of mammals, birds, reptiles and fishes. These early approaches relied on simple evaporation techniques and worked mainly with naturally abundant proteins such as hemoglobin. In 1909, the physiologist Edward T. Reichert, together with the mineralogist Amos P. Brown, published a treatise on the preparation, physiology and geometrical characterization of hemeoglobin crystals from several hundreds animals, including extinct species such as the Tasmanian wolf. Increasing protein crystals were found.
Sources: en.wikipedia.org
Because sites of protein-protein interaction have often been found to be flanked by prolines, the presence of the two prolines in this ‘finger’ of the structure indicates a possible interaction site. A short polypeptide of eight amino acid residues, containing this sequence, was indeed found to block the L-type calcium channels, though with a lesser activity. These interacting amino acids are also found in two other L-type calcium channel blocking proteins, C10S2C2 and S4C8. Although both of these toxins are members of the three-fingered family, the three-fingered structure is probably not a requirement for channel blocking: other snake toxins, including dendrotoxin, have similar effects on various channels, but do not show the three-fingered structure.
Therapeutic, diagnostic and preventive monoclonal antibodies are clones of a single parent cell. When used as drugs, the International Nonproprietary Names (INNs) end in -mab. The remaining syllables of the INNs, as well as the column Source, are explained in Nomenclature of monoclonal antibodies.
This means that the signal can be measured by an oscilloscope in trigger mode. Indeed, the first GC-MS was done in 1950 using an oscilloscope. The experimenters took quick photos of the oscilloscope screen for each component exiting the gas chromatography machine. This distribution in velocities broadens the peaks shown on the count vs m/z plot, but will generally not change the central location of the peaks, since the starting velocity of ions is generally centered at zero. To fix this problem, time-lag focusing/delayed extraction has been coupled with TOF-MS. If the ions do not start at identical kinetic energies, then some ions may lag behind higher kinetic energy ions decreasing resolution. Reflectron geometries are commonly employed to correct this problem. Longer tubes result in higher resolution. A reflector doubles the effective tube length. A reflector-TOF can reach a resolution of several thousands. For their low resolution, TOF mass spectrometers makes up for it in speed. They are particularly useful in chemical kinetics studies. It can study rapid reactions such as combustion and explosions.
β particles emit lower energy as compared to α-emitters, but they have the advantage of having longer path length. However, due to their lower energy, more β particles are required to cause damage to tumor cells as compared to α-emitters. Some examples of β-emitters are 177Lu, 90Y, and 131I.
Banting, November 14, 1891–February 22, 1941". Journal of the American Dietetic Association. 29 (11): 1093. PMID 13108539. Les caprices du Nobel by William Rostène, ed. L'Harmattan (Paris), 2013 (in French) ISBN 978-2-343-01844-7
Sources: en.wikipedia.org
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.
No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.
It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.