thymosin beta-4 fragment is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-05-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
TB-500 refers to a synthetic peptide fragment derived from the actin-binding region of thymosin beta-4, a protein present in most mammalian cells. The full protein contains forty-three amino acids, while the commonly sold fragment is a much shorter acetylated sequence, often cited as LKKTETQ. The fragment retains part of the actin-binding motif but lacks the remainder of the parent protein. Material sold under this name is usually lyophilized powder intended for laboratory research, and it is not a finished pharmaceutical product.
Proposed activity centers on actin sequestration and on the movement of cells during repair processes. In cell culture and animal models, the fragment has been associated with migration, tube formation, and tissue remodeling. These observations are frequently described as preliminary, because most published work uses rodent or in vitro systems rather than controlled human trials. Whether the short fragment reproduces the effects of the full protein remains an open question, and the relationship between dose, route, and measured outcome is not well characterized.
The compound circulates in the literature as a research reagent rather than an approved therapeutic. Regulatory agencies in several countries have not authorized it for medical use, and sporting bodies list related thymosin beta-4 peptides among prohibited substances. Suppliers typically market it with a purity figure and a certificate of analysis, while peer-reviewed clinical reports remain sparse. Discussions therefore often separate laboratory findings from anecdotal reports, and reviewers tend to note the small size and methodological limits of the available studies.
TB-500 is a synthetic seven-amino-acid peptide with the sequence LKKTETQ, corresponding to residues 17 through 23 of the protein thymosin beta-4. The N-terminus is typically acetylated in the described form, giving a monoisotopic mass near 888.5 Da and an average mass of about 889 Da. The designation TB-500 is a catalogue label rather than a formal chemical name, and the same sequence appears in the literature under several alternative abbreviations. It is handled as a research reagent rather than a pharmaceutical product.
Thymosin beta-4 is a 43-residue actin-binding protein found in most mammalian cell types, where it participates in cytoskeletal regulation and cell migration. TB-500 represents only a short fragment of that protein and does not include the remaining residues. Whether the isolated fragment reproduces the full range of activities reported for the intact protein remains an open question. Researchers commonly treat the two as related but distinct entities when comparing results.
Published work involving this sequence spans actin-binding assays, cell-migration studies, wound-healing models, and cardiovascular or musculoskeletal experiments. Much of the biological rationale derives from in vitro systems and animal models, and the number of controlled human studies is small. Reported outcomes vary across preparations, doses, and routes, which complicates comparison between studies. Reviews generally describe the evidence base as preliminary rather than settled. Mechanistic explanations are often proposed by analogy to the parent protein rather than demonstrated directly.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid as supplied |
| Water solubility | Soluble | Dissolves in aqueous media |
| Typical storage temperature | -20 °C | Dry powder, desiccated, protected from light |
| Typical analytical method | RP-HPLC with mass spectrometry | Purity from peak area; mass for identity |
| Common synonyms | Tβ4 fragment; thymosin beta-4 fragment | Naming varies by supplier and catalogue |
TB-500 is a synthetic heptapeptide with the sequence Ac-LKKTETQ. It corresponds to a short N-terminal region of thymosin beta-4, a 43-amino-acid protein found in many cell types. The fragment contains an actin-binding motif, which is one reason it appears in laboratory studies of cell migration and cytoskeletal dynamics. TB-500 is not the full-length protein and is produced as a research chemical rather than an approved therapeutic agent. Its molecular weight is approximately 889 Da.
Several names appear in scientific and commercial contexts for this peptide. The label TB-500 is informal and does not follow standard biochemical nomenclature. Research articles more often describe the compound as a thymosin beta-4 fragment, Tβ4 fragment, or by its sequence Ac-LKKTETQ. Confusing TB-500 with full-length thymosin beta-4 can lead to incorrect assumptions about activity because the fragment lacks the remaining residues of the parent protein. The relationship between fragment and parent protein remains an active area of study.
Thymosin beta-4 itself is a natural peptide of 43 residues found in many cell types and body fluids. Its best-characterised function is binding and sequestering actin monomers, which influences cytoskeletal dynamics. The sequence most often associated with TB-500, LKKTETQ, corresponds to part of that actin-binding region. A different fragment, Ac-SDKP, is also derived from the same parent peptide and is studied in its own right, which is one reason discussions of thymosin fragments can become confusing. The two are structurally distinct and are not interchangeable.
Interest in the fragment grew during the 1990s and 2000s, when it moved from laboratory work into sports and supplement markets. Anti-doping bodies added thymosin beta-4 fragments to prohibited lists, and a small number of adverse analytical findings have been reported in competition testing. Published controlled human trials remain scarce. Most mechanistic evidence comes from cell culture and animal models, and those studies examine endpoints such as cell migration, wound closure and inflammation markers. That evidence supports research interest but does not establish clinical benefit, and broad regenerative claims should be read as unverified.
Nucleic acids consist of a chain of linked units called nucleotides. Each nucleotide consists of three subunits: a phosphate group and a sugar (ribose in the case of RNA, deoxyribose in DNA) make up the backbone of the nucleic acid strand, and attached to the sugar is one of a set of nucleobases. The nucleobases are important in base pairing of strands to form higher-level secondary and tertiary structures such as the famed double helix. The possible letters are A, C, G, and T, representing the four nucleotide bases of a DNA strand – adenine, cytosine, guanine, thymine – covalently linked to a phosphodiester backbone. In the typical case, the sequences are printed abutting one another without gaps, as in the sequence AAAGTCTGAC, read left to right in the 5' to 3' direction. With regards to transcription, a sequence is on the coding strand if it has the same order as the transcribed RNA. One sequence can be complementary to another sequence, meaning that they have the base on each position in the complementary (i.e., A to T, C to G) and in the reverse order. For example, the complementary sequence to TTAC is GTAA. If one strand of the double-stranded DNA is considered the sense strand, then the other strand, considered the antisense strand, will have the complementary sequence to the sense strand.
On March 21, 1991, a Royal Saudi Air Force C-130H crashed in heavy smoke due to the Kuwaiti oil fires on approach to Ras Mishab Airport, Saudi Arabia. 92 Senegalese soldiers and 6 Saudi crew members were killed, the largest accident among Coalition forces. The smoke screening was also used by Iraqi anti-armor forces to a successful extent in the Battle of Phase Line Bullet, having aided in achieving the element of surprise against advancing Bradley IFVs, along with increasing the general fog of war. The fires burned out of control because of the dangers of sending in firefighting crews during the war. Land mines had been placed in areas around the oil wells and military demining was necessary before the fires could be put out. Around 5 million barrels (790,000 m3) of oil were lost each day. Eventually, privately contracted crews extinguished the fires, at a total cost of US$1.5 billion to Kuwait. By that time, however, the fires had burned for approximately ten months, causing widespread pollution. The fires have been linked with what was later deemed Gulf War syndrome, a chronic disorder afflicting military veterans and civilian workers that include fatigue, muscle pain, and cognitive problems; however, studies have indicated that the firemen who capped the wells did not report any of the symptoms that the soldiers experienced. The cause of Gulf War syndrome has since been ascribed to Sarin nerve agent.
=== Medication === Medications for AS may be broadly considered either "disease-modifying" or "symptom-modifying". Disease-modifying medications for ankylosing spondylitis aim to slow disease progression and include drugs like tumor necrosis factor (TNF) inhibitors. Symptom-modifying medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), primarily address symptoms like pain and inflammation but do not alter the course of the disease.
Sources: en.wikipedia.org
=== Silver Medal at 1948 Summer Olympics === Yugoslavia began their football campaign by defeating Luxembourg 6–1, with five different players scoring the goals. In the quarter-finals and the semi-finals, they would take out Turkey and Great Britain by the same score of 3–1. In the final though, they would lose to Sweden.
CH3OH + H2S → CH3SH + H2O Such reactions are conducted in the presence of acidic catalysts. The other principal route to thiols involves the addition of hydrogen sulfide to alkenes. Such reactions are usually conducted in the presence of an acid catalyst or UV light. Halide displacement, using the suitable organic halide and sodium hydrogen sulfide has also been used. Another method entails the alkylation of sodium hydrosulfide.
== Adverse effects == The adverse side effects of amphetamine are many and varied, and the amount of amphetamine used is the primary factor in determining the likelihood and severity of adverse effects. Amphetamine products such as Adderall, Vyvanse, and their generic equivalents are currently approved by the U.S. FDA for long-term therapeutic use. Recreational use of amphetamine generally involves much larger doses, which have a greater risk of serious adverse drug effects than dosages used for therapeutic purposes.
Sources: en.wikipedia.org
== Etymology == The term tempe is thought to be derived from the Old Javanese tumpi, a whitish food made of fried batter made from sago or rice flour which resembles rempeyek. The historian Denys Lombard also suggests that it could be linked to a later term tape or tapai which means 'fermentation'. In the western world, tempeh rather than tempe is the most common spelling, to emphasise that the final "e" is pronounced. The first known usage of this spelling is in an 1896 German article. Other spellings, such as témpé, were also used, but tempeh has become the standard spelling in English since the 1960s.
In October 1912, when the 6th Chugoku Six Prefectures United Livestock Breeders' Show was held in Himeji City, Hyōgo Prefecture, two crossbred bulls won first prize as "Improved Japanese Breed" (改良和種, kairyō washu) and the term "Improved Japanese Breed" came into use thereafter. Thereafter, organized breeding efforts to increase the number of superior Wagyu cattle began. According to a survey conducted in 1914, there were 61 different breeds of Wagyu in Japan at that time, including Tajima cattle, Iwaizumi cattle, Mishima cattle, Aso cattle, and others. However, these were not actual breeds, but only names of regional classifications. In the case of Hyōgo Prefecture, the leading producer of Wagyu cattle (Kobe cattle and Tajima cattle) at that time, the number of stud bulls owned by breed as of 1914 was as follows.
== Professional ventures and affiliations == Early in his career, Ariely co-founded the behavioral economics consulting firm BEworks, which was acquired by Kyu in 2017. In 2012, aspiring to develop a time management app that helps people "use time better" and avoid procrastination, Ariely co-founded Timeful with Yoav Shoham and Jacob Bank. The app was acquired by Google in 2015. In 2013, Ariely and Kristen Berman co-founded Irrational Labs, a consulting firm aimed at applying behavioral economics to consumer behavior and decision-making. In 2014, Ariely co-founded the kitchen appliance company Genie with Ayelet Carasso-Stenberg and Doron Marco. Genie manufactures a food "replicator" that cooks freeze-dried meals in cartridges. In 2015, Ariely invested in Qapital, a personal finance app, and was appointed as its chief behavioral economist. He was later named chair of the board. In 2015, Ariely gave a talk at Google about dating and relationships, discussing what women want from men, including how women's attraction to men varies depending where they are in their menstrual cycle. This was one of many talks Ariely collaborated with Google on over several years, including, for example, a talk about how people rationalize cheating. In 2016, he took on the position of chief behavioral officer at Lemonade, an insurance company that integrates aspects of behavioral economics into its insurance model. Ariely's entrepreneurial ventures also include founding Shapa in 2017, a company focused on health monitoring and behavior change.
=== Contest history === 2009 NABBA England - 2nd 2009 NABBA Universe - 2nd 2009 UKBFF Hercules - 1st 2010 UKBFF British Championships - 1st 2011 Arnold Amateur Europe - 4th 2011 Women's World Amateur Championships - 4th (HW) 2013 Arnold Amateur Europe - 2nd 2014 IFBB Tampa Pro - 16th 2015 IFBB Omaha Pro - 1st 2015 IFBB Wings of Strength Rising Phoenix World Championships - 9th 2016 IFBB Tampa Pro - 2nd 2016 IFBB Wings of Strength Rising Phoenix World Championships – 7th 2017 IFBB Tampa Pro - 2nd 2017 IFBB WOS Rising Phoenix World Championships – 9th 2018 IFBB Tampa Pro - 4th 2019 IFBB Romania Muscle Fest Pro - 6th 2022 IFBB WOS Rising Phoenix World Championships – 14th
Sources: en.wikipedia.org
TB-500 is a name used for a short synthetic peptide fragment taken from the actin-binding region of thymosin beta-4. Material sold under this label is usually a lyophilized powder supplied for laboratory research rather than a licensed medicine. The commonly cited sequence is LKKTETQ.
The parent protein contains forty-three amino acids, while the fragment carries only a short motif from one region. The fragment can interact with actin in vitro, but it does not include the rest of the protein structure. Whether the shorter molecule behaves the same way in living systems is not settled.
Published controlled human studies are scarce, and most activity reports come from cell culture or animal models. Reviews often describe the evidence base as limited and methodologically uneven. Open questions include the relationship between route, dose, and measured outcomes.
No. TB-500 is a short synthetic peptide matching residues 17 to 23 of thymosin beta-4, while the parent protein contains 43 residues. The fragment lacks the rest of the protein sequence, so the two are related but not identical.