This is a working overview of counterion, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-12-26. Anything still debated is marked as such rather than presented as settled.
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.
| 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 |
Typical storage for the lyophilized powder is −20 °C or lower, in a sealed container protected from light and moisture. Hygroscopic material should be allowed to equilibrate to room temperature before the vial is opened, which limits condensation on the contents. Working solutions are commonly divided into single-use aliquots and frozen to avoid repeated freeze-thaw cycles. Dilute solutions are more prone to adsorption onto plastic surfaces and to loss during filtration, so procedures that minimize transfers and use low-binding labware are preferable.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
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.
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.
== Overdose == In the event of arsenic poisoning (manifesting as seizures, muscle weakness, confusion), the administration of the drug should be immediately discontinued, and appropriate treatment should be initiated. Penicillamine is commonly used at a dose of up to 1 g/day. For patients unable to take oral medications, dimercaprol can be administered intramuscularly at a dose of 3 mg/kg body weight every 4 hours until life-threatening symptoms subside. In cases of coagulopathy, DMSA is recommended at a dose of 10 mg/kg body weight every 8 hours for 5 days, followed by every 12 hours for 2 weeks. Kidney dialysis may also be considered.
=== Lodotra === "Lodotra" is the brand name of an oral formulation, which releases prednisone four hours after ingestion. It is indicated for rheumatoid arthritis with morning stiffness. Taken at 10 p.m., it releases the drug at around 2 a.m. The plasmic peak level is reached at 4 a.m., which is considered to be the optimal time for relieving morning stiffness. The drug was approved in the European Union, in January 2009.
=== Interwar years (1919-1941) === Following the Ottoman Empire's post-World War I dismemberment and the foundation of the successor Turkish Republic in 1923, Mustafa Kemal Atatürk banned all Sufi orders and installed the Directorate of Religious Affairs as sole governing entity over religion. Bektashi lodges in Turkey were subsequently closed in 1925, with the order's leadership relocating to Albania and establishing its headquarters in Tirana. Salih Nijazi was the last Dedebaba in Turkey and the first in Albania, formerly appointed to his role in the latter country on 30 March 1930. The order became involved in Albanian politics, and some of its members, including Ismail Qemali, were major leaders of the Albanian National Awakening (Rilindja). After the lodges in Turkey were shut down, the order's headquarters moved to Albania. On 20 March 1930, Salih Nijazi was elected as the Dedebaba of the Bektashi community in Albania. Before Nijazi, the Dedebaba was Haxhi Fejzullah in Turkey. Njazi established the Bektashi World Headquarters in Tirana. Its construction was finished in 1941 during the Italian occupation of Albania. Nijazi promoted Bektashi Islam by introducing major ceremonies at popular tekkes. After he was murdered in 1941, Ali Riza succeeded him as the Dedebaba.
April 9: Law establishing the postal savings bank: regardless of her marital status, a wife does not need her husband's permission to open a postal savings account or withdraw money from it—unless the husband expressly objects. June 16: Law establishing free primary education in public schools: these also include girls' schools in communes with more than 400 inhabitants. August 2: Decree organizing nursery schools—coeducational, they accept children aged 2 to 7; all directors and workers are women; female general and departmental inspectors are assigned to their oversight. Girls are granted access to secondary education, with specific provisions and a diploma different from the baccalaureate (which boys may obtain). March 28, 1882: Law on mandatory primary education for both boys and girls between the ages of 6 and 13; school curricula differ only in that girls learn needlework and boys take military exercises. July 27, 1884: Law reinstating divorce. 1885
Sources: en.wikipedia.org
=== Availability === Buserelin is marketed in the United Kingdom, Ireland, other European countries, Canada, New Zealand, and South Africa, as well as in Latin America, Asia, and elsewhere in the world. It is not available in the United States or Australia.
These discoveries led numerous countries to begin working on the development of nuclear weapons and nuclear power. Despite fission having been discovered in Germany, the Uranverein ("uranium club") Germany's wartime project to research nuclear power and/or weapons was hampered by limited resources, infighting, the exile or non-involvement of several prominent scientists in the field and several crucial mistakes such as failing to account for impurities in available graphite samples which made it appear less suitable as a neutron moderator than it is in reality. Germany's attempts to build a natural uranium / heavy water reactor had not come close to reaching criticality by the time the Americans reached Haigerloch, the site of the last German wartime reactor experiment. On 2 December 1942, as part of the Manhattan Project, another team led by Enrico Fermi was able to initiate the first artificial self-sustained nuclear chain reaction, Chicago Pile-1. An initial plan using enriched uranium-235 was abandoned as it was as yet unavailable in sufficient quantities. Working in a lab below the stands of Stagg Field at the University of Chicago, the team created the conditions needed for such a reaction by piling together 360 tonnes of graphite, 53 tonnes of uranium oxide, and 5.5 tonnes of uranium metal, most of which was supplied by Westinghouse Lamp Plant in a makeshift production process.
Neprilysin is also associated with other biochemical processes, and is particularly highly expressed in kidney and lung tissues. Inhibitors have been designed with the aim of developing analgesic and antihypertensive agents that act by preventing neprilysin's activity against signaling peptides such as enkephalins, substance P, endothelin, and atrial natriuretic peptide. Associations have been observed between neprilysin expression and various types of cancer; however, the relationship between neprilysin expression and carcinogenesis remains obscure. In cancer biomarker studies, the neprilysin gene is often referred to as CD10 or CALLA. In some types of cancer, such as metastatic carcinoma and some advanced melanomas, neprilysin is overexpressed; in other types, most notably lung cancers, neprilysin is downregulated, and thus unable to modulate the pro-growth autocrine signaling of cancer cells via secreted peptides such as mammalian homologs related to bombesin. Some plant extracts (methanol extracts of Ceropegia rupicola, Kniphofia sumarae, Plectranthus cf barbatus, and an aqueous extract of Pavetta longiflora) were found able to inhibit the enzymatic activity of neutral endopeptidase.
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 based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.