A practical reference on epithalamin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-26 and is reviewed periodically as new material appears.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by HPLC area | Higher grades are also offered |
| Primary analytical method | Reversed-phase HPLC, UV detection | Frequently paired with mass spectrometry |
| Confirmatory technique | Electrospray mass spectrometry | Observed mass compared with theory |
| Storage temperature | Minus 20 degrees Celsius, dry powder | Sealed, desiccated, protected from light |
| Solution handling | Prepare fresh before use | Hydrolysis proceeds in aqueous media |
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.
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.
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.
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.
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.
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.
=== Absorption === Pentamidine is completely absorbed when given intravenously or intramuscularly. When inhaled through a nebulizer, pentamidine accumulates in the bronchoalveolar fluid of the lungs at a higher concentration compared to injections. The inhaled form is minimally absorbed in the blood, but the effects of chronic inhaled administration on these levels are not known. Absorption is unreliable when given orally.
In Lima the problem was that the delivery of territories had to be immediate, but not the payment of the debt, which caused the chancellor José María Pando and the President of the Governing Board Andrés de Santa Cruz to reject the treaty. They make it clear that they would hand over Arica or Iquique but only for immediate benefits. As for the federative idea, what was agreed established a very weak executive and legislature that would only generate chaos and make them dependent on Gran Colombia to maintain order, denouncing an anti-Peruvianism of part of Simón Bolívar and Antonio José de Sucre. Looking for alternatives, the Upper Peruvians sent the secret "legislative legation", a commission to ask Bolívar to suspend the decree of May 16, 1825 by which Arica was Peruvian, but they failed, since Bolívar did not want to provoke the people of Lima any more. There is also the anti-Peruvian belief that the War against the Peru-Bolivian Confederation was a Peruvian betrayal of Bolivia due to Bolivian nationalist hoaxes that the opposition of several Peruvians to the Union was motivated by being governed by a Bolivian (Andres de Santa Cruz), and that to avoid it, they ended up allying with Chile to achieve the fall of the confederation.
== Science and technology == Linear hashing, a computer science algorithm for a dynamic hash LH, a type of single-mode optical fiber LH (complexity) (for "logarithmic hierarchy"), a computational complexity class LH (DOS command), a DOS command that loads a program into the upper memory area Luteinizing hormone, a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland Windows Longhorn, the original code name during the development of Windows Vista
Hermes: A Java "mzData, mzXML, mzML" converter to all directions: publicly available, runs with a graphical user interface, by the Institute of Molecular Systems Biology, ETH Zurich FileConverter: A command line tool that converts to/from various mass spectrometry formats, part of TOPP Known converters for mzXML:
Sources: en.wikipedia.org
=== Product recalls === In May 2006, a sale of the seats from Arsenal F.C.'s old stadium, Highbury in London, England was cancelled when the seats were discovered to contain trace amounts of cadmium. Reports of high levels of cadmium use in children's jewelry in 2010 led to a US Consumer Product Safety Commission investigation. The U.S. CPSC issued specific recall notices for cadmium content in jewelry sold by Claire's and Wal-Mart stores. In June 2010, McDonald's voluntarily recalled more than 12 million promotional Shrek Forever After 3D Collectible Drinking Glasses because of the cadmium levels in paint pigments on the glassware. The glasses were manufactured by Arc International, of Millville, New Jersey, USA.
Immediately after the atomic bombings of Japan, the status of atomic weapons in international and military relations was unclear. Presumably, the United States hoped atomic weapons could offset the Soviet Union's larger conventional ground forces in Eastern Europe, and possibly be used to pressure Soviet leader Joseph Stalin into making concessions. Under Stalin, the Soviet Union pursued its own atomic capabilities through a combination of scientific research and espionage directed against the American program. The Soviets believed that the Americans, with their limited nuclear arsenal, were unlikely to engage in any new world wars, while the Americans were not confident they could prevent a Soviet takeover of Europe, despite their atomic advantage. Within the United States, the authority to produce and develop nuclear weapons was removed from military control and put instead under the civilian control of the United States Atomic Energy Commission. This decision reflected an understanding that nuclear weapons had unique risks and benefits that were separate from other military technology known at the time.
During World War II, German Type XXI submarines (also known as "Elektroboote") were the first submarines designed to operate submerged for extended periods. Initially they were to carry hydrogen peroxide for long-term, fast air-independent propulsion, but were ultimately built with very large batteries instead. At the end of the War, the British and Soviets experimented with hydrogen peroxide/kerosene (paraffin) engines that could run surfaced and submerged. The results were not encouraging. Though the Soviet Union deployed a class of submarines with this engine type (codenamed Quebec by NATO), they were considered unsuccessful. The United States also used hydrogen peroxide in an experimental midget submarine, X-1. It was originally powered by a hydrogen peroxide/diesel engine and battery system until an explosion of her hydrogen peroxide supply on 20 May 1957. X-1 was later converted to use diesel–electric drive. Today several navies use air-independent propulsion. Notably Sweden uses Stirling technology on the Gotland-class and Södermanland-class submarines. The Stirling engine is heated by burning diesel fuel with liquid oxygen from cryogenic tanks. A newer development in air-independent propulsion is hydrogen fuel cells, first used on the German Type 212 submarine, with nine 34 kW or two 120 kW cells. Fuel cells are also used in the new Spanish S-80-class submarines although with the fuel stored as ethanol and then converted into hydrogen before use.
Sources: en.wikipedia.org
On 20 February 1990 the Volkskammer passed a new electoral law, reducing it in size to 400 members elected via party-list proportional representation, with no electoral threshold. Joint lists between parties were allowed, and a number of parties formed alliances for the election, including the Association of Free Democrats, Alliance 90, and an alliance between the Green Party and Independent Women's Association. Seats were calculated nationally using the largest remainder method, and distributed in multi-member constituencies corresponding to the fifteen Bezirke.
Progesterone (P4), sold under the brand name Prometrium among others, is a medication and naturally occurring steroid hormone. It is a progestogen and is used in combination with estrogens mainly in hormone therapy for menopausal symptoms, and low sex hormone levels in women, as well as gender affirming therapy in transgender women. It is also used in women to support pregnancy and fertility and to treat gynecological disorders. Progesterone can be taken by mouth, vaginally, and by injection into muscle or fat, among other routes. A progesterone vaginal ring and progesterone intrauterine device used for birth control also exist in some areas of the world. Progesterone is well tolerated and often produces few or no side effects. However, a number of side effects are possible, for instance mood changes. If progesterone is taken by mouth or at high doses, certain central side effects including sedation, sleepiness, and cognitive impairment can also occur. The medication is a naturally occurring progestogen and hence is an agonist of the progesterone receptor (PR), the biological target of progestogens like endogenous progesterone. It opposes the effects of estrogens in various parts of the body like the uterus and also blocks the effects of the hormone aldosterone. In addition, progesterone has neurosteroid effects in the brain. Progesterone was first isolated in pure form in 1934. It first became available as a medication later that year. Oral micronized progesterone (OMP), which allowed progesterone to be taken by mouth, was introduced in 1980.
Briton Callum Tindal-Draper is killed while fighting with the 4th International Legion in Ukraine. 6 November – At Newcastle Crown Court, former GP Thomas Kwan is sentenced to 31 years in prison after posing as a community nurse to inject his mother's partner with a substance that caused him to contract a flesh eating disease following a row over inheritance. 7 November The Bank of England cuts the UK interest rate by 0.25% to 4.75%, but indicates further cuts may take longer than previously thought following the October budget, which it forecasts will lead to price increases. Argentinian authorities announce that three people have been charged in connection with the death of One Direction's Liam Payne. A report into more than 100 allegations of sexual abuse against barrister John Smyth QC, who died in 2018, finds his activities were covered up by the Church of England for several decades. Smyth used his home as a Christian summer camp during the 1970s and 1980s, when the abuse of boys and young men is thought to have happened. The Football Association opens a safeguarding inquiry into a Premiership club official following sexual allegations made by three women. The charity organisation Care England estimates that as a result of the increase in employers' National Insurance contributions and the national minimum wage in the recent budget, that the cost of providing care will increase by over £3,000 per person and that the increases are expected to be passed on to care home residents and their relatives.
=== Defects === There are two kinds of defects: Equilibrium defects, and Non-Equilibrium defects. Self-assembled structures contain defects. Dislocations caused during the assembling of nanomaterials can majorly affect the final structure and in general defects are never completely avoidable. Current research on defects is focused on controlling defect density.[23] In most cases, the thermodynamic driving force for self-assembly is provided by weak intermolecular interactions and is usually of the same order of magnitude as the entropy term. In order for a self-assembling system to reach the minimum free energy configuration, there has to be enough thermal energy to allow the mass transport of the self-assembling molecules. For defect formation, the free energy of single defect formation is given by:
Sources: en.wikipedia.org
The usual approach is reversed-phase HPLC with ultraviolet detection, reported as a percentage of total peak area. Mass spectrometry is used alongside chromatography to confirm identity rather than purity alone.
The dry powder is commonly kept at minus twenty degrees Celsius, desiccated and away from light. Solutions are generally prepared fresh because they break down faster than the solid form.
Tandem mass spectrometry or enzymatic peptide mapping can establish residue order. A single intact mass value indicates composition and molecular weight but not always the precise arrangement of residues.
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.