A practical reference on Tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-19 and is reviewed periodically as new material appears.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Free acid form of the tetrapeptide |
| Molecular mass | About 390.35 Da | Calculated monoisotopic value |
| Appearance | White to off-white powder | Typical lyophilized presentation |
| Solubility | Soluble in water | Also dissolves in buffered saline |
| Storage temperature | Minus 20 degrees Celsius | Dry, dark conditions; avoid repeated thawing |
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
=== Metabolome atlas of the aging mouse brain === In 2021, the first brain metabolome atlas of the mouse brain – and of an animal (a mammal) across different life stages – was released online. The data differentiates by brain regions and the metabolic changes could be "mapped to existing gene and protein brain atlases".
== Soundtrack == The film's original score was composed by Sylvester Levay. Electric guitars feature prominently, in contrast with Levay's more famous synth-driven sound. The film also features licensed songs, most notably from The Doobie Brothers and Sheryl Crow. Other featured artists, such as Saigon Kick and Cryer (who perform on screen during the strip club scene) were signed to Third Stone Records, a label recently founded by Michael Douglas and music producer Richard Rudolph.
=== Regional history prior to foundation of Lower Saxony === The name of Saxony derives from that of the Germanic confederation of tribes called the Saxons. Before the late medieval period, there was a single Duchy of Saxony. The term "Lower Saxony" was used after the dissolution of the stem duchy in the late 13th century to distinguish the parts of the former duchy ruled by the House of Welf from the Electorate of Saxony on one hand, and from the Duchy of Westphalia on the other.
Sources: en.wikipedia.org
, in order to characterize the geometry. This correction factor, also often referred to as the geometric shape factor, is given by empirically determined series and accounts for the type and geometry of the crack or notch. We thus have:
Therapeutic Heparin (>15 units/kg/h) Platelet count <30,000/mm3 Recent (within 6 weeks) gastrointestinal bleeding Recent administration (within 3 days) of thrombolytic therapy Recent administration (within 7 days) of oral anticoagulants or GP IIb/IIIa inhibitors Recent administration (within 7 days) of >650 mg/day of aspirin or other platelet inhibitors Recent (within 3 months) ischemic stroke Known or suspected intracranial AV malformation or aneurysm Known bleeding diathesis (e.g., hemophilia) except for acute coagulopathy related to sepsis Chronic severe hepatic disease HIV infection in association with a last known CD4 count of <50/mm3 Any other condition in which bleeding constitutes a significant hazard or would be particularly difficult to manage because of its location Because drotrecogin-alpha is a therapeutic protein, there exists a potential for immunogenicity. Antibodies against drotrecogin have been observed. There is insufficient data at this time to quantify the risk, but extreme caution should be exercised if a patient has previously received drotrecogin-alpha.
==== Illegal marketing of Rapamune settlement (2014) ==== A "whistleblower suit" was filed in 2005 against Wyeth, which was acquired by Pfizer in 2009, alleging that the company illegally marketed sirolimus (Rapamune) for off-label uses, targeted specific doctors and medical facilities to increase sales of Rapamune, tried to get transplant patients to change from their transplant drugs to Rapamune, and specifically targeted African Americans. According to the whistleblowers, Wyeth also provided doctors and hospitals that prescribed the drug with kickbacks such as grants, donations, and other money. In 2013, the company pleaded guilty to criminal mis-branding violations under the Federal Food, Drug, and Cosmetic Act. By August 2014, it had paid $491 million in civil and criminal penalties related to Rapamune.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.
No naturally occurring free form of the peptide has been described. The four-amino-acid sequence can appear as a fragment within larger proteins, but that is not the same as the intact compound being present as a circulating molecule. Materials used in research are synthetic.
Purity is usually checked by reverse-phase high-performance liquid chromatography, which separates the target peptide from related impurities. Mass spectrometry is commonly used alongside it to confirm molecular mass. Some suppliers also provide amino acid analysis for additional sequence confirmation.
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.