If you have been reading about Peptide storage and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
| Property | Value | Notes |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
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.
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.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
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.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
== Other translations == Dutch: Halverwege Haar Leven (1979), Spanish: Media vida (1979), Polish: Połowa życia (1980), Bulgarian: Половин живот (1981), Hungarian: Kettészakított élet, (1983), Slovak: Polovica zivota (1984), Portuguese: Meia Vida (1986), Czech: Půl žívota (1986).
=== Electrogenetics === Mammalian designer cells are engineered by humans to behave a specific way, such as an immune cell that expresses a synthetic receptor designed to combat a specific disease. Electrogenetics is an application of synthetic biology that involves utilizing electrical fields to stimulate a response in engineered cells. Controlling the designer cells can be done with relative ease through the use of common electronic devices, such as smartphones. Additionally, electrogenetics allows for the possibility of creating devices that are much smaller and compact than devices that use other stimulus through the use of microscopic electrodes. One example of how electrogenetics is used to benefit public health is through stimulating designer cells that are able to produce/deliver therapeutics. This was implemented in ElectroHEK cells, cells that contain voltage-gated calcium channels that are electrosensitive, meaning that the ion channel can be controlled by electrical conduction between electrodes and the ElectroHEK cells. The expression levels of the artificial gene that these ElectroHEK cells contained was shown to be able to be controlled by changing the voltage or electrical pulse length. Further studies have expanded on this robust system, one of which is a beta cell line system designed to control the release of insulin based on electric signals.
== Overview == A sequence begins with a greater-than character (">") followed by a description of the sequence (all in a single line). The lines immediately following the description line are the sequence representation, with one letter per amino acid or nucleic acid, and are typically no more than 80 characters in length. For example:
And there were more flash points outside of the war. On 6 May 1902 at Holkrantz in the southeastern Transvaal, a Zulu faction had their cattle stolen and their women and children tortured by the Boers as a punishment for assisting the British. The local Boer officer then sent an insulting message to the tribe, challenging them to take back their cattle. The Zulus attacked at night, and in a mutual bloodbath, the Boers lost 56 killed and 3 wounded, while the Indigenous Africans suffered 52 killed and 48 wounded. About 10,000 black men were attached to Boer units where they performed camp duties; a handful unofficially fought in combat. The British Army employed over 14,000 Indigenous Africans as wagon drivers. Even more had combatant roles as spies, guides, and eventually as soldiers. By 1902 there were about 30,000 armed Indigenous Africans in the British Army. Sol Plaatje was the only black person to keep a diary during the war, which later proved to be a valuable source about the black participation in the war.
Layer-by-layer (LbL) deposition is a thin film fabrication technique. The films are formed by depositing alternating layers of complementary materials with wash steps in between. One of the key advantages of LbL technology compared with other film deposition techniques is its ability to produce highly uniform conformal coatings on both flat and curved surfaces. This can be accomplished by using various techniques such as immersion, spin, spray, electromagnetism, or fluidics.
Sources: en.wikipedia.org
===== North America ===== Canada - DMT is classified as a Schedule III drug under the Controlled Drugs and Substances Act, but is legal for religious groups to use. In 2017 the Santo Daime Church Céu do Montréal received religious exemption to use ayahuasca as a sacrament in their rituals. United States - DMT is classified in the United States as a Schedule I drug under the Controlled Substances Act of 1970. In 2019, it was decriminalized, along with other naturally derived psychedelics, in the city of Oakland after a campaign by Decriminalize Nature.
=== 2000 === 13 March The Secret Life of the Crash Test Dummy, about the biomechanics of car crashes; a typical crash test dummy cost around £100,000, with about three hundred individual parts, that had to be included by safety law, and new cars could not be sold until the dummy had tested it sufficiently; the Volvo 300 1980s television advert; Lt-Col Wayne Mattson of the USAF and a strange crash in New Mexico, one hundred miles north of the Trinity (nuclear test), and near White Sands Missile Range, where German V-2 missiles were being tested, which were conveniently blamed by the USAF on anthropomorphic dummies; John Melvin (engineer) and the legacy of USAF biophysicist and doctor Colonel John Stapp, who mostly invented aviation safety testing; John Stapp conducted gruesome horrific deceleration tests on himself; Alderson had made artificial limbs for injured USAF World War II pilots, so made a full artificial proto-human; John Stapp tested his dummies in vehicles; Clarence Ditlow and the Center for Auto Safety; in 1966 it became legal in the US for new cars to have been tested by dummies; mathematical models of injury were needed, to translate the acquired crash data into possible effects on the human body, worked out by mechanical engineer Walter Pilkey of the University of Virginia; Scottish orthopaedic surgeon Angus Wallace and impact speed on bone tensile strength; in 1976 the Hybrid III dummy was designed, the automotive industry standard design; David Abbott, advertising executive; the data for designing the crash test dummy, Hybrid III, was mostly derived from data procured for human male occupants - and typical (fiftieth percentile) males, not female, and females had much different bodies; child dummies were essentially smaller adult male dummies, which was not biologically true; new dummies were developed at the National Transportation Biomechanics Research Center. Narrated by Andrew Lincoln, produced by Cathy Rogers, directed by Peter Webber, made by RDF Television. Shown on Wednesday 17 January 2001 on The Nature of Things in Canada 20 March Rise and Fall of GM Food, about genetically modified food; Belgian geneticist Marc Van Montagu, of the University of Ghent, visits Havana in Cuba, where a new research centre opened with Carlos Borroto; protests by topless women; GM was largely first developed by Mexican geneticist Herrera Estrella, of the Centre of Investigation and Advanced Studies; Rob Fraley of Monsanto; US farmers spend $8bn dollars on herbicides and pesticides; Roger N. Beachy had a breakthrough in 1986 at the Washington University in St. Louis, now at the Donald Danforth Plant and Science Center; Monsanto made the first insecticide-resistant plant in 1987; many African farmers cannot afford insecticides; Cyrus Ndiritu of the Kenya Agriculture Research Institute; much food harvested in Africa does not last before it reaches the consumer; in 1990 Don Grierson of the Plant Science Division of the University of Nottingham found genes of ripening; Channapatna Prakash of Tuskegee University in Alabama; aluminium toxicity of soils in tropical countries affected yield; Julian Borger of The Guardian; biologist Mae-Wan Ho of the Open University; biologist John Gatehouse of the University of Durham, and the Pusztai affair at The Rowett Institute; Helen Browning, Chairman of the Soil Association; former Vice-Chancellor of UEA, Derek Burke; former Independent environment correspondent Richard D. North, who had grown out of love with the hard-line environmental movement; European farmers grew five times more produce than they did in the 1960s, and there were twice as many trees in the UK than in the 1920s; Renée Elliott of Planet Organic; around 100m children in Third World countries suffered from Vitamin A deficiency. Directed by Martin Durkin, made by his company Kugelblitz 27 March Simply Complex, about the physicist Murray Gell-Mann; by an accident, he devised strangeness of sub-atomic particles, in his mid-20s; he predicts an omega minus particle, which was found in 1962; he predicts that the proton and neutron were made of three triplet particles, which he called quarks from Finnegans Wake and his Eightfold way (physics), also predicted by George Zweig; he worked closely with Richard Feynman at Caltech in the 1960s; on 30 October 1969 he is told that he had won the Nobel Prize for Physics; his friendship with MIT mechanical engineer Seth Lloyd; British physicist Geoffrey West; the documentary is in a biographic informal style that Horizon has since often followed. Produced by Barbara Altounyan, directed by Celia Lowenstein, made by Diverse Productions 3 April Meningitis - Search for a Cure, 3,000 people in the UK had meningitis in 1999; microbiologist Martin C. J. Maiden; one in five died from meningococcal disease; damage is caused by the endotoxin (lipopolysaccharide); a healthy survey is carried out at Burford School; Mike Levin (paediatrician) at Imperial College, and how meningitis A is a huge danger in Africa; 60% of cases in the UK are meningitis B, and many such cases are treated at St Mary's Hospital, London; Brett Giroir of the Children's Medical Center Dallas; 17-year-old Amy Mansell from Whitstable was in a coma for five weeks. Narrated by Paul Brightwell, produced by David Dugan, directed by Jeremy Llewellyn-Jones, made by Windfall Films with Nova and WGBH Boston. It was shown on Nova as Killer Disease on Campus, episode 9 of season 29, shown on 3 September 2002, and shown under the original programme title as a half-hour programme on 6 November 2003 on Catalyst on ABC in Australia 10 April The Box, about flight recorders, with ValuJet Airlines Flight 592 which crashed on 11 May 1996; voice recorders have been compulsory since the late 1960s; Dukane Seacom make emergency underwater locator beacons (ULBs); the Boeing 737, which had around 21,000 take-offs per day, was believed to have unreliable rudder control since the 1980s, as shown in the United Airlines Flight 585 crash on 3 March 1991, having had two rudder incidents in the previous two weeks, with the aircraft flipping 35 seconds after take-off and crashing all in seven seconds; the electrohydraulic servo valve in the Boeing 737 rudder control unit was thought to be sometimes temperamental; Boeing claimed that the March 1991 crash was due to a rotor or lee wave, caused by nearby mountains; the USAir Flight 427 crash on 8 September 1994, where the aircraft flipped at 6,000 ft, in 28 seconds crashing; British Airways did not rely on their Penny & Giles quick access recorders, and would consolidate this data where anomalies were checked, so the NTSB needed BA's data for their 737 aircraft; this safer BA method was introduced by the previous British European Airways (BEA) when it had to prove to the CAA that its autoland system for the Trident was safe, in the Civil Aircraft Airworthiness Data Recording Programme which since 1990 has been collected by the British Airways Safety Information System (BASIS); the 1991 crash investigation concluded after 8 years in 1999, with Boeing ordered to redesign the servo valve. 9 October Full Throttle, about the technology and psychology of motor racing; Brazilian driver Christian Fittipaldi; the Eurofighter, controlled by computers, and due to enter RAF service in 2002; Archie Neill, BAE test pilot; Stephen Olvey, motor racing medical officer; driver Mark Blundell; the Long Beach Grand Prix in Los Angeles; Steve Clark, engineer for Mercedes; Brian Lisles and Peter Gibbons of Newman Haas Racing; the edge of performance envelope; Mario Andretti, former driver: Edward Winter of Sheffield Hallam University and predicting outcomes in sport, by intuition; John Rothwell of the Institute of Neurology in London, testing reflexes, by an MRI scanner, and how the brain stores instructions; psychologist Mike Land of the University of Sussex, and the psychology of prediction, and feedforward; life expectancy of racing drivers in the 1970s was short; racing drivers had risk positive personalities, and became accustomed to risk; psychologist Tim Wheeler; Jimmy Vasser of Chip Ganassi Racing; a female violinist plays La fille aux cheveux de lin; sports psychologist Brian Hemmings; Austrian driver Alexander Wurz of Benetton Formula; RAF SEPECAT Jaguar XZ103 of 41 Squadron; engineer Pat Symonds of Benetton Racing; Simon Taylor (journalist) of Motor Sport; Graham Rood of DERA Air Systems in north Hampshire. Narrated by Stephen Rashbrook, produced by Patrick Uden, directed by Andy Robbins, made by Uden Associates 16 October Lethal Seas: the Maelstrom, about ocean whirlpools; the Gulf of Corryvreckan in Scotland, Lofoten and Saltstraumen in Norway; with Prof Tsukasa Nishimura of Tokyo University of Science and Prof Walter Munk of the Scripps Institution of Oceanography; the Firth of Lorn in west Scotland has one of the world's most dangerous whirlpools, the Royal Navy avoids it; atmospheric physicist Peter Read; mathematician David Dritschel, and the Great Red Spot vortice; the dangerous Arran Rapids on the Cordero Channel in western Canada; Burkard Baschek of the Institute of Ocean Sciences, who dropped a CTD (instrument) into the torrential river currents; Tremble Island in the notorious Slingsby Channel, where a geophone was placed; the novel A Descent into the Maelström; Bjørn Gjevik, a fluid dynamicist in the Department of Mathematics, at the University of Oslo; strong tidal currents in the Naruto Strait in Japan, and the Naruto whirlpools. Narrated by Stephen Rashbrook, produced by Robert Sproul-Cran, directed by Kim Flitcroft, made by Northlight Productions with the Discovery Channel 23 October Einstein's Biggest Blunder, about calculations of the expansion of the universe; the documentary opens with a pastiche of the Star Wars opening credits; two physicists met in 1996, with a new radical proposal for explaining the many anomalies in the expansion of the universe - Andreas Albrecht (cosmologist) of the University of California, Davis and João Magueijo of Portugal; Dave Wark of the University of Sussex, visits Bern in Switzerland; Ruth Durrer of the University of Geneva; John E. Baldwin of the University of Cambridge, and the 1887 Michelson–Morley experiment, which found that the Earth's rotational speed did not affect the speed of light in any way, alongside the Venus movement of The Planets; to account for this, Einstein made his field equations, and lambda - the cosmological constant was added by Einstein to account for how space-time would need to expand; Einstein's equations inferred that the expansion of the universe rested on inherently unstable conditions; due to the Doppler effect, background radiation from the Big Bang is now perceived as microwave radiation; Richard Ellis (astronomer) of Caltech; Einstein didn't believe in the Big Bang until a meeting with Hubble in 1932 in California; with the new theory of an expanding universe, the cosmological constant was now required, but the precise trajectory of the expansion of the universe could not be directly predicted, which led to the flatness problem; the theory of inflation was put forward by Alan Guth in the 1970s; when at St John's College, Cambridge, João Magueijo had the radical proposal that if the speed of light was higher, in the early universe, a cosmological horizon of sufficient distance would be possible, to explain the predicted conditions of the expansion of the early universe, and the cosmological constant problem; the Royal Society gave him a research fellowship to work at Imperial College; as further exploratory work was clocked up, with calculations inclya variable speed of light, the team of physicists looked at other applications for their controversial proposals, such as the flatness problem, and what happened before the Big Bang; in 1998 astrophysicist John Webb, at the University of Cambridge, worked on the theory of a variable speed of light, through investigating quasars, the most distant objects that can be seen; and by looking at supernovae, it was largely expected that any recorded data would show indications of a deceleration in the rate of expansion of the universe, but the data instead showed that the rate of expansion was - increasing, which led to the lambda-CDM model. Narrated by Scottish actor Matthew Zajac, directed by David Sington, made by Dox Productions 30 October The Science of Stress, with 42-year-old actor Angus Kennedy; endocrinologist Stafford Lightman of the University of Bristol; Vivette Glover, a perinatal psychobiological at Imperial College; Sir Cary Cooper, psychologist at the former UMIST; Carolyn M. Mazure, psychiatrist at Yale School of Medicine; Charles Nemeroff, psychiatrist at Emory University School of Medicine. Narrated by Geoffrey Palmer, directed by Michael Samuels, produced by Bridget Sneyd, made by Lion Television and the Discovery Health Channel 7 December Science of Crime - Psychopath, with psychologists Robert D. Hare and Adrian Raine, about the psychopathic traits of insincere superficial charm, on the Psychopathy Checklist. Narrated by Neil Pearson, directed by John Purdie, produced by Rosalind Arden, made by Union Pictures 14 December Science of Crime - Criminal Evidence, about the forensic psychologist 49-year-old Kathy Reichs. Produced by Geoff Deehan, directed by Roger Pyke, made by Yap Films 21 December Science of Crime - Cybercops, the Hackers on Planet Earth conference; Cult of the Dead Cow, founded by Swamp Rat, and its Back Orifice software for accessing Windows 98; the Happy99 virus; wardialing; part of the High Technology Theft Apprehension and Prosecution Program in California. Narrated by Steven Mackintosh, written by Callum Macrae, directed by Witold Starecki
R3N + 3 H2 → 3 RH + H3N R2S + 2 H2 → 2 RH + H2S Hydrogenolysis can be applied to the conversion of virtually any functional group into hydrocarbons. Substrates include haloalkanes, alcohols, aldehydes, ketones, carboxylic acids, etc. Both hydrogenolysis and hydrogenation are practiced in refineries. They can be effected by using lithium aluminium hydride, Clemmenson reduction and other specialized routes.
To promote weight gain and muscle growth As an adjunct in the treatment of bone pain and decreased bone strength associated with osteoporosis As an adjunct for catabolic states such as corticosteroid therapy and convalescence as in chronic infections, extensive surgery, and severe trauma To treat treatment-refractory anemias (via stimulation of erythropoiesis) such as acquired and congenital aplastic anemia and anemia of chronic kidney disease As an adjunct to improve strength and well-being in arthritis To treat short stature in youth
=== Books === Wadden, Thomas A.; Van Itallie, Theodore B. (1992). Treatment of the Seriously Obese Patient. Guilford Press. Stunkard, Albert J.; Wadden, Thomas A. (1993). Obesity: Theory and Therapy (2nd ed.). Raven Press. Brownell, Kelly D.; Wadden, Thomas A. (1998). The LEARN Program for Weight Control: Special Medication Edition. American Health Publishing. Wadden, Thomas A.; Stunkard, Albert J. (2002). Handbook of Obesity Treatment. Guilford Press. Wadden, Thomas A.; Bray, George A. (2018). Handbook of Obesity Treatment (2nd ed.). Guilford Press.
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.