Everything below concerns thymosin beta-4. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
Thymosin beta-4 was isolated from calf thymus in the early 1980s and later characterised as an abundant intracellular actin-sequestering protein. Interest in short synthetic fragments grew once the actin-binding motif had been mapped to the middle of the sequence. TB-500 came out of that line of work as a truncated analogue rather than a natural isolate, and it is now sold mainly to laboratories. Published studies on the fragment have been largely in vitro or in animal models, and controlled human trials remain sparse, so claims about effects in people rest on extrapolation.
Literature and online discussion often conflate TB-500 with full-length thymosin beta-4, even though the two differ in size and are not interchangeable in analytical terms. The fragment is produced by solid-phase peptide synthesis, and the product is a defined seven-residue chain rather than a biological extract. Because the term is a trade-style label, two vendors may supply materials of the same nominal sequence but different counter-ion content, purity, or water content. Comparisons across studies are therefore difficult unless the exact sequence and purity are reported.
TB-500 is a research peptide whose sequence matches residues 17 to 23 of thymosin beta-4, a 43-residue protein present in most mammalian cells. The chain is seven amino acids long, written as LKKTETQ, and is normally supplied with an acetyl group on the N-terminus. Suppliers list it as a lyophilised powder under the code name TB-500, and the same sequence appears elsewhere in catalogues as the thymosin beta-4 actin-binding fragment. The label is commercial rather than systematic, so no single authority fixes exactly what TB-500 denotes.
Interest in the peptide grew during the 2000s and 2010s, when studies of tendon and ligament injuries in horses reported changes in lesion size after treatment. Those reports circulated widely outside the scientific literature and shaped much of the current online discussion. Subsequent reviews noted inconsistent study design, small groups, and a shortage of independent replication. Popular descriptions often blur the line between the fragment, the complete protein, and unrelated growth factors, which complicates comparisons across sources.
TB-500 is a synthetic peptide whose sequence corresponds to a short fragment near the N-terminus of thymosin beta-4, a small protein present in most mammalian cells. The fragment is commonly cited as containing the actin-binding region of the parent molecule, which is why it appears in laboratory work on cell migration and tissue repair. Suppliers distribute it as a lyophilised powder intended for research use. Its identity is defined by amino acid sequence and by the presence of an acetyl group on the N-terminal residue.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Supplied as a lyophilised cake in sealed vials |
| Solubility class | Freely soluble in water | Polar and charged side chains dominate the sequence |
| Typical storage temperature | -20 °C or below | Dry and dark; a desiccant is often recommended |
| Identity confirmation | Mass spectrometry | Observed mass compared with the theoretical value |
| Common synonyms | Thymosin beta-4 fragment | Also written as T beta 4 fragment 17-23 |
Thymosin beta-4 contains 43 amino acids and has a reported molecular mass near 4963 Da. The short fragment most often associated with the TB-500 label, an acetylated chain beginning LKKTETQ, has a reported mass near 889 Da, so the two are easily separated in analytical work. Mass spectrometry and amino acid analysis can confirm which material is present in a given sample. Statements treating TB-500 and thymosin beta-4 as interchangeable are therefore imprecise, even though the two appear together in much of the same literature.
Interest in the compound comes largely from studies of the parent protein, which participates in actin sequestration, cell migration and tissue repair processes. Whether a short fragment reproduces those activities is a separate question that remains open in the published record. Many summaries describe mechanisms by analogy to thymosin beta-4 rather than from direct measurements on the fragment. Claims about activity should be treated as provisional unless a cited study specifies the exact peptide, its purity and the assay used.
Discussion of TB-500 appears in several distinct literatures that rarely cite one another. Peer-reviewed studies usually describe in vitro assays or small animal experiments and are cautious about extrapolation. Veterinary and sports communities circulate anecdotal reports with limited methodological detail. Commercial listings add a third layer, often using the name interchangeably with thymosin beta-4 even though the two molecules differ in size and sequence. Regulatory status varies by country, and the compound is not a licensed medicine in most jurisdictions, so readers comparing sources should check which molecule and which purity each source actually describes.
TB-500 is a synthetic seven-residue peptide whose sequence, LKKTETQ, matches the N-terminal actin-binding region of thymosin beta-4. It is usually supplied in an N-terminally acetylated form, a modification that blocks the free amino terminus and can influence behavior in solution. In the research literature the same sequence appears under several names, including thymosin beta-4 fragment and shortened thymosin beta-4. Because it is a short peptide rather than the full 43-residue parent protein, its measured properties differ from those reported for thymosin beta-4 as a whole, and the two are not interchangeable in experimental design.
Material sold under this label typically arrives as a freeze-dried powder in a sealed vial with a certificate of analysis. Such certificates usually report reversed-phase chromatography purity plus a mass confirmation, and stated purities commonly sit between 95 and 99 percent. Counter-ion identity, residual trifluoroacetate, water content, and peptide net weight are separate specifications that a certificate may or may not include. A purity figure alone does not establish sequence identity, so independent mass verification remains the practical check.
The designation TB-500 circulates in laboratory and catalog contexts without a single agreed definition. Most product listings apply it to an N-terminally acetylated seven-residue fragment of thymosin beta-4, while other listings attach the same label to the full 43-residue protein. Because the term is commercial rather than systematic, two entries bearing identical names may describe different molecules. Any documentation should therefore state which sequence a given sample is claimed to contain.
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 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.
As the confinement energy depends on the quantum dot's size, both absorption onset and fluorescence emission can be tuned by changing the size of the quantum dot during its synthesis. The larger the dot, the redder (lower-energy) its absorption onset and fluorescence spectrum. Conversely, smaller dots absorb and emit bluer (higher-energy) light. Recent articles suggest that the shape of the quantum dot may be a factor in the coloration as well, but as yet not enough information is available . Furthermore, it was shown that the lifetime of fluorescence is determined by the size of the quantum dot. Larger dots have more closely spaced energy levels in which the electron–hole pair can be trapped. Therefore, electron–hole pairs in larger dots live longer causing larger dots to show a longer lifetime. To improve fluorescence quantum yield, quantum dots can be made with shells of a larger bandgap semiconductor material around them. The improvement is suggested to be due to the reduced access of electron and hole to non-radiative surface recombination pathways in some cases, but also due to reduced Auger recombination in others.
In May 1945, following its defeat in World War II, Germany was occupied by the United States, Britain, France and the Soviet Union. All four occupation powers reorganised the territories by recreating the Länder (states), the constituting parts of federal Germany. The state of Prussia, whose provinces extended to all four zones and covered two thirds of Germany, was abolished in 1947. Special conditions were assigned to Berlin, which the four powers divided into four sectors. A united German state government existed in the city until it broke apart in 1948. After 1949, both West Berlin and East Berlin (officially only called Berlin) were in effect incorporated into the Federal Republic of Germany and the German Democratic Republic, respectively, despite not legally being part of these countries.
As pH rises above 0 the above yellow hydrolyzed species form and as it rises above 2–3, reddish-brown hydrous iron(III) oxide precipitates out of solution. Although Fe3+ has a d5 configuration, its absorption spectrum is not like that of Mn2+ with its weak, spin-forbidden d–d bands, because Fe3+ has higher positive charge and is more polarizing, lowering the energy of its ligand-to-metal charge transfer absorptions. Thus, all the above complexes are rather strongly colored, with the single exception of the hexaquo ion – and even that has a spectrum dominated by charge transfer in the near ultraviolet region. On the other hand, the pale green iron(II) hexaquo ion [Fe(H2O)6]2+ does not undergo appreciable hydrolysis. Carbon dioxide is not evolved when carbonate anions are added, which instead results in white iron(II) carbonate being precipitated out. In excess carbon dioxide this forms the slightly soluble bicarbonate, which occurs commonly in groundwater, but it oxidises quickly in air to form iron(III) oxide that accounts for the brown deposits present in a sizeable number of streams.
== Similar conditions == Vacuoles may form in neutrophils if a blood sample is left standing for several hours prior to blood smear preparation, but this is an artifactual change with no clinical significance. Artifactual vacuoles are small and of uniform size and distribution, in contrast to toxic vacuoles whose size and placement are variable. Individuals with neutral lipid storage disease may exhibit persistent lipid-filled vacuoles in neutrophils and other granulocytes, which is a distinct phenomenon termed Jordans' anomaly.
== Publications == Tongraar, A.; Liedl, K. R.; Rode, Bernd M. (1997);"Solvation of Ca2+ In Water Studied By Born-Oppenheimer Ab-Initio QM/MM Dynamics"; J. Phys. Chem. A 1997, 101(35), p. 6299-6309,DOI: 10.1021/jp970963t. Rode, Bernd M.; Schwenk, Christian F., Tongraar, Anan (2004); "Structure and Dynamics of Hydrated Ions - New Insights through Quantum Cechanical Simulation"; J. Mol. Liq. 2004, 110(1-3), pp. 105–122. DOI: 10.1016/j.molliq.2003.09.016. Hofer, Thomas; Pribil, Andreas; Randolf, Bernhard; Rode, Bernd M. (2005); "Structure and dynamics of solvated Sn(II) in aqueous solution - an ab initio QM/MM MD approach", J. Am. Chem. Soc. 2005, 127(41), p. 14231-14238. DOI:10.1021/ja052700f. Rode, Bernd M.; Schwenk, Christian; Hofer, Thomas; Randolf, Bernhard (2005); "Coordination and ligand exchange dynamics of solvated metal ions"; Coord. Chem. Rev. 2005, 249(24), pp. 2993-–3006. DOI: doi:10.1016/j.ccr.2005.03.032. Rode, Bernd M.; Hofer, Thomas (2006); "How to Access Structure and Dynamics of Solutions: The Capabilities of Computational Methods", Pure Appl. Chem. 2006, 78(3), pp. 525–539. DOI: 10.1351/pac200678030525. Rode, Bernd M.; Hofer, Thomas; Randolf, Bernhard; Schwenk, Christian; Xenides, Demetrios; Vchirawongkwin, Viwat(2006); "Ab initio Quantum Mechanical Charge Field (QMCF) Molecular Dynamics - A QM/MM - MD Procedure for Accurate Simulations of Ions and Complexes"; Theor. Chem. Acc. 2006, 115(2-3), pp. 77–85. DOI: 10.1007/s00214-005-0049-1. Hofer, Thomas S.; Randolf, Bernhard R.; Rode, Bernd M.
Sources: en.wikipedia.org
=== Non-dairy milk offerings === In 1997, Starbucks first offered non-dairy milk at its U.S. stores with the introduction of soy milk. In 2007, Starbucks stopped using milk originating from rBGH-treated cows. The company also adopted a new dairy standard for all espresso-based drinks, switching from whole to 2% reduced fat milk. In 2015, Starbucks began serving coconut milk. In 2016, it began serving almond milk. In January 2020, oat milk became available nationally. The company also offers non-dairy creamers at retail in partnership with Nestlé SA. CEO Kevin Johnson said in a 2020 interview that, milk substitutes would be a big part of reducing carbon emissions. That effort has prompted vegans, environmentalists, people with lactose intolerance and others to urge the company to eliminate the upcharge for drinks made with dairy-free milk. PETA encouraged sit-ins at Starbucks locations and purchased Starbucks stock to draw attention to what they believe is an unfair charge. A Starbucks Canada spokesperson told ET Canada that customizations such as added flavours, non-dairy beverages or an additional shot of espresso, would incur an additional charge. In December 2020, Starbucks announced it would offer Oatly oat milk in all US stores starting in spring 2021. With the launch of their holiday menu in November 2024, Starbucks ended the upcharge for non-dairy milk additions to drinks.
=== Awards and honours === Winner of the CA/Zurich Business Leader Award in 2002 Winner of the inaugural Trans-Tasman Business Leader Award in 2005 Awarded a Doctor of Business honoris causa by RMIT University in 2008 Appointed Officer of the Order of Australia (AO) in 2010 for service to the development of the transport and logistics industries through strategic leadership and promotion of corporate social and environmental responsibility, and to the community through philanthropic support of sporting and medical research organisations. Little is also a Fellow of the Australian Institute of Company Directors and a Fellow of the Chartered Institute of Logistics and Transport (FCILT).
=== Premature ejaculation === Randomized, double-blind, placebo-controlled trials have confirmed the efficacy of dapoxetine for the treatment of PE. Different dosages have different impacts on different types of PE. Dapoxetine 60 mg significantly improves the mean intravaginal ejaculation latency time (IELT) compared to that of dapoxetine 30 mg in men with lifelong PE, but no difference is seen in men with acquired PE. Dapoxetine, given 1–3 hours before sexual episode, prolongs IELT and increases the sense of control and sexual satisfaction in men of 18 to 64 years of age with PE. Since PE is associated with personal distress and interrelationship difficulty, dapoxetine provides help for men with PE to overcome this condition. With no drug approved specifically for treatment for PE in the US and some other countries, other SSRIs such as fluoxetine, paroxetine, sertraline, fluvoxamine, and citalopram have been used off-label to treat PE. Waldinger's meta-analysis shows that the use of these conventional antidepressants increases IELT two- to nine-fold above baseline, compared to three- to eight-fold when dapoxetine is used. However, these SSRIs may need to be taken daily to achieve meaningful efficacy, and their comparatively longer half-lives increase the risk of drug accumulation and a corresponding increase of adverse effects such as reduced libido. Dapoxetine, though, is generally categorized as a fast-acting SSRI. It is more rapidly absorbed and mostly eliminated from the body within a few hours.
=== 1976 === January 8: Chinese Premier Zhou Enlai dies of cancer. February: Soviet and Cuban forces install a communist government in Angola. March 24: The National Reorganization Process takes power in Argentina following a successful military coup and launches military action against Argentine-based guerrillas. Jorge Rafael Videla is installed as president. May 4: The Corsican conflict begins, with the aim of an independent Corsican state against the French government by Corsican nationalists. June 29: The Seychelles becomes independent from the UK, as a republic in the Commonwealth of Nations. July 2: Vietnam is officially reunited under a communist regime. July 20: U.S. Military personnel withdraw from Thailand. September 1: Inception of Safari Club. September 9: Death of Mao Zedong. December 4: Insurgency in Aceh begins. Jean-Bédel Bokassa proclaimed himself as Emperor of the Central African Empire.
Sources: en.wikipedia.org
==== Fistula formation and gallstone ileus ==== The inflammation of cholecystitis can lead to adhesions between the gallbladder and other parts of the gastrointestinal tract, most commonly the duodenum. These adhesions can lead to the formation of direct connections between the gallbladder and gastrointestinal tract, called fistulas. With these direct connections, gallstones can pass from the gallbladder to the intestines. Gallstones can get trapped in the gastrointestinal tract, most commonly at the connection between the small and large intestines (ileocecal valve). When a gallstone gets trapped, it can lead to an intestinal obstruction, called gallstone ileus, leading to abdominal pain, vomiting, constipation, and abdominal distension.
==== One-stepwise pyrolysis and two-stepwise pyrolysis for tobacco waste ==== Pyrolysis has also been used in trying to mitigate tobacco waste. One method was done where tobacco waste was separated into two categories, TLW (Tobacco Leaf Waste) and TSW (Tobacco Stick Waste). TLW was determined to be any waste from cigarettes and TSW was determined to be any waste from electronic cigarettes. Both TLW and TSW were dried at 80 °C for 24 hours and stored in a desiccator. Samples were grounded so that the contents were uniform. Tobacco Waste (TW) also contains inorganic (metal) contents, which was determined using an inductively coupled plasma-optical spectrometer. Thermo-gravimetric analysis was used to thermally degrade four samples (TLW, TSW, glycerol, and guar gum) and monitored under specific dynamic temperature conditions. About one gram of both TLW and TSW were used in the pyrolysis tests. During these analysis tests, CO2 and N2 were used as atmospheres inside of a tubular reactor that was built using quartz tubing. For both CO2 and N2 atmospheres the flow rate was 100 mL min−1. External heating was created via a tubular furnace. The pyrogenic products were classified into three phases. The first phase was biochar, a solid residue produced by the reactor at 650 °C. The second phase liquid hydrocarbons were collected by a cold solvent trap and sorted by using chromatography. The third and final phase was analyzed using an online micro GC unit and those pyrolysates were gases.
== Adverse effects == Some adverse events reported in preliminary clinical trials are somnolence, agitation, nausea, diarrhea, and dyspepsia. The adverse effect profile of ulotaront differs from that of other antipsychotics because its mechanism of action does not involve antagonism of dopamine receptors in the brain, which is responsible for the drug-induced movement disorders (like akathisia) that may occur with those agents.
A definitive diagnosis is made after based on growth hormone concentrations or increased IGF-1 levels. In male dogs with no history of progestogen administration the possibility of a pituitary tumour needs to be examined via CT/MRI. In cats with difficult to manage diabetes but no other signs of hypersomatotropism, the potential for other causes of poor glycaemic control need to be considered.
In August 2016, Taco Bell brought back its Pink Strawberry Starburst Freeze. In October 2015, Taco Bell launched a certified vegetarian menu. In August 2016, Taco Bell announced it would begin testing a mashup known as Cheetos Burritos at select Taco Bell restaurants On September 19, 2016, Taco Bell launched Airheads Freeze, a drink inspired by the candy Airheads White Mystery, and allow people to guess its flavor on social media. On September 15, 2016, Taco Bell introduced the Cheddar Habanero Quesarito, a quesadilla shelled burrito. In April 2017, Taco Bell announced that it would begin testing the Naked Breakfast Taco in Flint, Michigan in mid-April. The breakfast taco, which uses a fried egg as the shell for potato bites, nacho cheese, shredded cheddar, and bacon or sausage crumble. In 2017, the company released the Naked Chicken Chalupa that uses a chalupa shell made from chicken, using a similar idea to the Double Down and later that year the Naked Chicken Chips, which are chicken nuggets shaped like chips with nacho cheese. In July 2017, Taco Bell announced a partnership with Lyft in which Lyft passengers in Orange County, California, can request "Taco Mode" on their way to their destination from 9 PM to 2 AM, having a stop at Taco Bell. The program was cancelled after much negative feedback from drivers. On September 21, 2018, Taco Bell announced National Taco Day celebrating its global reach outside of the United States, to be celebrated in 20 countries. In January 2019, Taco Bell nearly doubled its television advertising spending to US$64 million.
Sources: en.wikipedia.org
No. Thymosin beta-4 is a 43-residue protein, while TB-500 matches only residues 17 to 23 of that chain. The two are related but differ in size, and a method that identifies one does not automatically identify the other.
It corresponds to the actin-binding region of thymosin beta-4. Commercial synthesis reproduces that seven-residue stretch, usually with an acetyl group on the N-terminus.
It is not authorised as a medicine in the United States or the European Union and is distributed as a research chemical. Labels consequently carry research-use-only statements rather than clinical indications.
It is a synthetic peptide based on a short sequence near the start of thymosin beta-4. It is supplied as a research chemical rather than as a licensed pharmaceutical product.