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 2026-04-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
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.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
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.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
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.
== In individuals without HIV/AIDS == Since the HIV/AIDS epidemic in the 1980s, IRIS is now mostly associated with the initiation of HIV treatment with highly active antiretroviral therapy (HAART), also referred to as antiretroviral therapy (ART). However, IRIS can still occur in the following conditions that do not involve HIV:
11-Deoxycortisol in mammals has limited biological activity and mainly acts as metabolic intermediate within the glucocorticoid pathway, leading to cortisol. However, in sea lampreys, an early jawless fish species that originated over 500 million years ago, 11-deoxycortisol is the primary and ultimate glucocorticoid hormone with mineralocorticoid properties; 11-deoxycortisol also takes part, by binding to specific corticosteroid receptors, in intestinal osmoregulation in sea lamprey at metamorphosis, during which they develop seawater tolerance before downstream migration. Sea lampreys do not possess the 11β-hydroxylase enzyme (CYP11B1) responsible for converting 11-deoxycortisol to cortisol and 11-deoxycorticosterone to corticosterone, as observed in mammals. The absence of this enzyme in sea lampreys indicates the existence of a complex and highly specific corticosteroid signaling pathway that emerged at least 500 million years ago with the advent of early vertebrates. The lack of cortisol and corticosterone in sea lampreys suggests that the presence of the 11β-hydroxylase enzyme may have been absent during the early stages of vertebrate evolution. The absence of cortisol and corticosterone in sea lampreys suggests that the 11β-hydroxylase enzyme may not have been present early in vertebrate evolution.
In one well-known 1974 case series, 8 people accidentally insufflated two "lines" of nearly pure LSD powder that they thought were cocaine. The exact doses of LSD were unknown, but were considered to be massive. For context, a typical "line" of cocaine for insufflation is 50 to 100 mg. The individuals reported to the hospital within 10 to 15 minutes, with five of them comatose, three requiring intubation and mechanical ventilation, and the conscious individuals experiencing severe hallucinogenic effects, among other toxic symptoms. All of them completely recovered within 12 hours and there were no deaths. A subsequent 2020 case similarly involved accidental insufflation of a confirmed 55 mg dose of LSD instead of cocaine, which was without adverse health consequences. In other reports, a 5 mg overdose of LSD produced severe nausea and vomiting along with severe behavioral disturbances, while a 10 mg overdose was also non-fatal. Despite acting as non-selective serotonin receptor agonists, major psychedelics like LSD and psilocybin do not cause serotonin syndrome even with extreme overdose. This is thought to be because they act as partial agonists of serotonin receptors like the serotonin 5-HT2A receptor relative to serotonin itself. Conversely, NBOMe psychedelics like 25I-NBOMe are more efficacious and have been uniquely associated with serotonin syndrome-like toxicity. A 2018 retrospective analysis of 3,554 LSD-only exposures reported to poison control centers in the United States between 2000 and 2016 found that serious toxicity was infrequent.
Molecular engineering is highly interdisciplinary by nature, encompassing aspects of chemical engineering, materials science, bioengineering, electrical engineering, physics, mechanical engineering, and chemistry. There is also considerable overlap with nanotechnology, in that both are concerned with the behavior of materials on the scale of nanometers or smaller. Given the highly fundamental nature of molecular interactions, there are a plethora of potential application areas, limited perhaps only by one's imagination and the laws of physics. However, some of the early successes of molecular engineering have come in the fields of immunotherapy, synthetic biology, and printable electronics (see molecular engineering applications). Molecular engineering is a dynamic and evolving field with complex target problems; breakthroughs require sophisticated and creative engineers who are conversant across disciplines. A rational engineering methodology that is based on molecular principles is in contrast to the widespread trial-and-error approaches common throughout engineering disciplines. Rather than relying on well-described but poorly-understood empirical correlations between the makeup of a system and its properties, a molecular design approach seeks to manipulate system properties directly using an understanding of their chemical and physical origins. This often gives rise to fundamentally new materials and systems, which are required to address outstanding needs in numerous fields, from energy to healthcare to electronics.
Sources: en.wikipedia.org
==== Oral testosterone ==== Testosterone is well-absorbed but extensively metabolized with oral administration due to the first pass through the intestines and liver. It is rapidly and completely inactivated in men at doses of less than 200 mg. In large doses, such as 200 mg however, significant increases in circulating testosterone levels become apparent. In addition, while a 60 mg dose has no effect on testosterone levels in men, this dose does measurably increase testosterone levels in prepubertal boys and women. The oral bioavailability of testosterone in young women after a single 25 mg dose was found to be 3.6 ± 2.5%. High levels of testosterone are also achieved with a 60 mg dose of oral testosterone in men with liver cirrhosis. These findings are attributed to induction of liver enzymes by testosterone and consequent activation of its own metabolism. Substitution dosages of oral testosterone in men are in the range of 400 to 800 mg/day. Such doses exceed the amount of testosterone produced by the body, which is approximately 7 mg/day, by approximately 100-fold. The elimination half-life of oral testosterone is rapid at about 5 to 7 hours. As a result, it requires administration several times per day in divided doses. Due to its limitations, such as the high doses required and necessity of multiple daily doses, oral testosterone is not used clinically in its unmodified form. Oral testosterone has been studied in combination with a 5α-reductase inhibitor to reduce its first-pass metabolism and improve its bioavailability.
The Chinese government has introduced a number of "fat farms" where obese children go for reinforced exercise and has passed a law which requires students to exercise or play sports for an hour a day at school (see Obesity in China). In a structured setting with a trained therapist, these interventions produce an average weight loss of up to 8 kg in 6 months to 1 year, and 67% of people who lost greater than 10% of their body mass maintained or continued to lose weight one year later. There is a gradual weight regain after the first year of about 1 to 2 kg per year, but on the long-term this still results in weight loss. Risk factors for cardiovascular disease and for diabetes are reduced for several years after taking part in a weight management programme, even if people regained weight. Attending group meetings for weight reduction programmes rather than receiving one-on-one support may increase the likelihood that obese people will lose weight. Those who participated in groups had more treatment time and were more likely to lose enough weight to improve their health. Study authors suggested that one explanation for the difference is that group participants spent more time with the clinician (or whoever delivered the programme) than those receiving one-on-one support. Comprehensive diet programs, providing counseling, targets for calorie intake and exercise, may be more efficient than dieting without guidance ("self-help"), although the evidence is very limited.
Compounds were developed with 3 macrocyclic chelators: DOTA, NODAGA, and CB-TE2A. DOTA had already been used as a chelator in the radiolabeled somatostatin agonists, as well as NODAGA and CB-TE2A. Ga-NODAGA-based compounds were shown to have a higher binding affinity than its DOTA analogues. However, these somatostatin receptor antagonists showed a higher tumor uptake despite its lower affinity for ssrt receptors, due to being able to bind a receptor despite its activation status. Compounds containing one of the radionuclides of indium-111, lutetium-177, copper-64, yttrium-80 and gallium-68 have been made. A study indicated the gallium compound had the lowest affinity to the sstr2 receptor.
Rice (1932–2024), physical chemist Ellen Swallow Richards (1842–1911), industrial and environmental chemist Theodore William Richards (1868–1928), 1914 Nobel Prize in Chemistry Wim Richter (1946–2019), South Africa Jeremias Benjamin Richter (1762–1807), German chemist, first used the term stoichiometry Nikolaus Riehl (1901–1990), German chemist Andrés Manuel del Río (1764–1849), Spanish-Mexican geochemist, discovered vanadium Robert Robinson (1886–1975), British chemist, 1947 Nobel Prize in Chemistry Pierre Jean Robiquet (1780–1840), French chemist, discovered caffeine, alizarin, cantharidin Hillar Rootare (1928–2008), Estonian-American physical chemist Irwin Rose (1926–2015), 2004 Nobel Prize in Chemistry Guillaume-François Rouelle (1703–1770), French chemist Hilaire-Marin Rouelle (1718–1779), French chemist Frank Sherwood Rowland (1927–2012), 1995 Nobel Prize in Chemistry Daniel Rutherford (1749–1819), Scottish chemist Ernest Rutherford (1871–1937), New Zealand born chemist and nuclear physicist. Discovered the proton. Nobel Prize in Chemistry 1908 Leopold Ruzicka (Lavoslav Ružička) (1887–1976), 1939 Nobel Prize in Chemistry
=== TV documentaries === ARTE (French/German TV Channel): Since 2018, ARTE has aired documentaries on the world of fascia, featuring Robert Schleip. SWR (German TV Channel): Documentaries aired on October 25, 2021, and September 10, 2020, explored the "fascia boom" and included contributions from Schleip.
Sources: en.wikipedia.org
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.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.