A practical reference on epitalon: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-02 and is reviewed periodically as new material appears.
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.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
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.
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.
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.
Tyrosine hydroxylase is a tetramer of four identical subunits (homotetramer). Each subunit consists of three domains. At the carboxyl terminal of the peptide chain there's a short alpha helix domain that allows tetramerization. The central ~300 amino acids make up a catalytic core, in which all the residues necessary for catalysis are located, along with a non-covalently bound iron atom. The iron is held in place by two histidine residues and one glutamate residue, making it a non-heme, non-iron-sulfur iron-containing enzyme. The amino terminal ~150 amino acids make up a regulatory domain, thought to control access of substrates to the active site. In humans there are thought to be four different versions of this regulatory domain, and thus four versions of the enzyme, depending on alternative splicing, though none of their structures have yet been properly determined. It has been suggested that this domain might be an intrinsically unstructured protein, which has no clearly defined tertiary structure, but so far no evidence has been presented supporting this claim. It has however been shown that the domain has a low occurrence of secondary structures, which doesn't weaken suspicions of it having a disordered overall structure. As for the tetramerization and catalytic domains their structure was found with rat tyrosine hydroxylase using X-ray crystallography. This has shown how its structure is very similar to that of phenylalanine hydroxylase and tryptophan hydroxylase; together the three make up a family of homologous aromatic amino acid hydroxylases.
Half-Life was followed by an expansion pack, Opposing Force, on November 1, 1999, developed by Gearbox Software. Players control US Marine corporal Adrian Shephard, who fights a new group of aliens and black operations units. Opposing Force was received favorably by critics, many citing the game as being as influential on setting expansion pack standards as the original game had been in influencing the overall genre. The game won the Computer Game of the Year Interactive Achievement Award of 2000 from the Academy of Interactive Arts & Sciences.
== Additional biological roles == Stress-induced adrenal hormone increase may upregulate GnIH release, as some GnIH neurons have adrenal glucocorticoid receptors. GnIH may therefore mediate interactions between the HPG and HPA (hypothalamic-pituitary-adrenal) axes and play a role in stress-related infertility. GnIH neurons of the paraventricular nucleus in the hypothalamus also express melatonin receptors. Because melatonin secretion is modulated by environmental light patterns, melatonin influence on GnIH production may enable photoperiodic regulation of reproduction in seasonally breeding birds, rodents, and sheep. GnIH increases food consumption, implying a role in appetite. This finding is consistent with the location of most GnIH neurons, as the dorsomedial nucleus of the hypothalamus is involved in appetite regulation. GnIH may allow the energy reserves of an organism to modulate reproduction. Higher levels of thyroid hormone suppress GnIH expression, and lower levels of thyroid hormone are associated with higher GnIH levels. The inactivation of GnIH expression prevents delayed puberty caused by hypothyroidism, demonstrating that GnIH mediates interactions between the HPG and HPT (hypothalamic-pituitary-thyroid) axes. Furthermore, thyroid hormone may function in a pathway for photoperiodic regulation of reproduction involving GnIH and energy status. Melatonin modulates thyroid-stimulating hormone (TSH) production in the anterior pituitary, and TSH promotes thyroid hormone production.
== External links == Roda, A. (2005). "Toward Multianalyte Immunoassays: A Flow-Assisted, Solid-Phase Format with Chemiluminescence Detection". Clinical Chemistry. 51 (10): 1993–1995. doi:10.1373/clinchem.2005.053108. ISSN 0009-9147. PMID 16299900.
Sources: en.wikipedia.org
The Gallery of Botany is on the Allée the Buffon facing the centre of the garden, between the Gallery of Mineralogy and the Gallery of Palaeontology. At the corner is one of the two oldest trees in Paris, a Robinia pseudoacacia or black locust, planted in 1635 by Vespasien Robin, the royal gardener and botanist, from an earlier tree brought from America by his brother, also a botanist, in 1601. It is tied in age with another from the same source planted at the same time on the square of Saint-Julien-le-Pauvre. The Gallery was built in 1930–35 with a grant from the Rockefeller Foundation. Directly in front is a statue entitled "Science and Mystery" by Jean-Louis Schroeder, made in 1889. It depicts an old man pondering an egg, contemplating the enigma of which came first. The primary content of the gallery is the Herbier National, a collection representing 7.5 million plants collected since the founding of the museum. They are divided for study into Spermatophytes, plants which reproduce with seeds, and cryptogams, plants which reproduce with spores, such as algae, lichens and mushrooms. Many of the plants were collected by Jean Baptiste Christophore Fusée Aublet, the royal pharmacist and botanist in French Guiana. In 1775 he published his "Histoire des plantes de la Guiane Française" describing 576 genera and 1,241 species of neotropical plants, including more than 400 species that were new to science, at a time when only 20,000 plants had been described, The ground floor interior of the gallery has vestibules built in a combination of Art Deco and Neo-Egyptian styles.
Afamelanotide is a synthetic tridecapeptide and a structural analogue of α-melanocyte stimulating hormone (α-MSH). It is a melanocortin receptor agonist and binds predominantly to the MC1 receptor. Its binding lasts longer than that of α-MSH. This results in part from afamelanotide's resistance to immediate degradation by serum or proteolytic enzymes. It is thought to cause skin darkening by binding to the MC1 receptor which in turn drives melanogenesis. It has a short half-life of approximately 30 minutes. After administration with implantation into the skin, the majority of the drug is released within two days, with 90% released by the fifth day. By the tenth day, no drug is detectable in plasma. The details of drug distribution, metabolism and excretion remain unclear (as of 2026), but since it is a small peptide with a short half-life, it is expected that it is quickly broken down into shorter peptide fragments and amino acids.
No paralogs of c7orf26 have been found in the human genome, however, six unique isoforms have been identified. They are c7orf26 isoform (X1, X2, X3, X4) and isoform 2 (two sub-isoforms identified). Below is a table of a variety of orthologs of the human c7orf26. The table include closely, intermediately and distantly related orthologs. Orthologs of the human protein c7orf26 are listed above in descending order of the date of divergence. c7orf26 is highly conserved throughout all orthologs, this is demonstrated with a 65% identity in the least similar ortholog. c7orf26 has evolved slowly and evenly over time. Below is a phylogenetic tree showing the evolutionary history of c7orf26 and its nearest orthologs.
The world annual production of the various species of Chlorella was 2000 tonnes (dry weight) in 2009, with the main producers being Germany, Japan and Taiwan. C. vulgaris is a candidate for commercial production due to its high resistance against adverse conditions and invading organisms. In addition, the production of the various organic macromolecules of interest (proteins, lipids, starch) differ depending on the technique used to create biomass and can be therefore targeted. Under more hostile conditions, the biomass decreases, but lipids and starch contents increase. Under nutrient and light-replete conditions, protein content increases along with the biomass. Different growth techniques have been developed. Different modes of growth (autotrophic, heterotrophic, and mixotrophic) has been investigated for Chlorella vulgaris; autotrophic growth is favoured as it does not require provision of costly organic carbon and relies on inorganic carbon sources (CO2, carbonates) and light for photosynthesis. Chlorella sp. cultivated in digested and membrane-pretreated swine manure is capable of improving the growth medium performance of microalgae cultivations in terms of final biomass productivity, showing that algal growth depends on the turbidity of liquid digestate streams rather than on their nutrient availability.
The kappa and lambda light chains undergo rearrangements of the V and J gene segments. In this process, a functional Vlambda can combine with four functional Jλ –Cλ combinations. On the other hands, Vk gene segments can join with either one of the Jk functional gene segments. The overall rearrangements result in a gene segment order from 5 prime to 3 prime end. These are a short leader (L) exon, a noncoding sequence (intron), a joined VJ segment, a second intron, and the constant region. There is a promoter upstream from each leader gene segment. The leader exon is important in the transcription of light chain by the RNA polymerase. This sequence is translated to guide the polypeptide to the internal environment of the endoplasmic reticulum, but is cleaved and absent from the mature protein. To remain with coding sequence only, the introns are removed during RNA- processing and repairing.
Sources: en.wikipedia.org
2. Int J Pharm Compd. 2026 Jul-Aug;30(4):329-336. Synthetic Peptides in Pharmacy Compounding: Analysis of PCAC Recommendations and Industry Safety Standards. Willis J(1), Vu N(2)(3). Author information: (1)University of Oklahoma College of Pharmacy. (2)ARL Bio Pharma, Oklahoma City, Oklahoma. Nvu@arlok.com. (3)University of Oklahoma College of Pharmacy, Oklahoma City, Oklahoma. Compounded peptides have quickly moved from a niche topic to a growing area of interest among patients and prescribers. These products are promoted for a wide range of uses, including tissue repair, inflammation, metabolic health, and healthy aging. This article examines the proposed uses of these peptides, the concerns raised during the review, and the practical implications for compounders. Copyright© by International Journal of Pharmaceutical Compounding, Inc.
== Animal harvesting == When not synthesized, collagen can be harvested from animal skin. This has led to deforestation, as has occurred in Paraguay, where large collagen producers buy large numbers of cattle hides from regions that have been clear-cut for cattle grazing.
=== Neutron source === The oxide of 241Am pressed with beryllium is an efficient neutron source. Here americium acts as the alpha source, and beryllium produces neutrons owing to its large cross-section for the (α,n) nuclear reaction:
Sanofi's application was considered by the same Endocrinologic and Metabolic Drugs Advisory FDA Committee that was considering lixisenatide as a single agent. In May 2016 by a vote of 12–2, with several members of the committee expressing reservations about Sanofi's plans to offer two pens with different ratios of insulin glargine and lixisenatide - one for people who had never taken insulin before and one for people who had; there was also concern about how to handle dosing when switching people from a single drug regimen to the combination drug. In August 2016 the FDA told Sanofi that it was delaying a final decision for three months, and asked Sanofi for more data on how people used the delivery devices. In November 2016, the FDA approved Sanofi's Soliqua formulation (insulin glargine 100 units/mL and lixisenatide 33 mcg/mL). Soliqua became available in American pharmacies in January 2017.
The term vitamin is derived from the word vitamine, which was coined in 1912 by Polish biochemist Casimir Funk, who isolated a complex of water-soluble micronutrients essential to life, all of which he presumed to be amines. When this presumption was later determined not to be true, the "e" was dropped from the name, hence "vitamin". Vitamin nomenclature was alphabetical, with Elmer McCollum calling these fat-soluble A and water-soluble B. Over time, eight chemically distinct, water-soluble B vitamins were isolated and numbered, with pantothenic acid as vitamin B5. The essential nature of pantothenic acid was discovered by Roger J. Williams in 1933 by showing it was required for the growth of yeast. Three years later Elvehjem and Jukes demonstrated that it was a growth and anti-dermatitis factor in chickens. Williams dubbed the compound "pantothenic acid", deriving the name from the Greek word pantothen, which translates as "from everywhere". His reason was that he found it to be present in almost every food he tested. Williams went on to determine the chemical structure in 1940. In 1953, Fritz Lipmann shared the Nobel Prize in Physiology or Medicine "for his discovery of co-enzyme A and its importance for intermediary metabolism", work he had published in 1946.
Sources: pubmed.ncbi.nlm.nih.gov
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.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
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.