View source for Taurine

{{short description|Aminosulfonic acid}}
{{About|the chemical compound|the bovine sub-species|Taurine cattle}}
{{cs1 config|name-list-style=vanc|display-authors=6}}
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 413848354
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageFile = Taurin.svg
| ImageAlt = Skeleton diagram of taurine molecule
| ImageClass = skin-invert-image
| ImageFile2 = Taurine-from-xtal-Mercury-3D-balls.png
| ImageAlt2 = Ball-and-stick model of taurine molecule
| ImageClass2 = bg-transparent
| PIN = 2-Aminoethanesulfonic acid
| OtherNames =Tauric acid
|Section1={{Chembox Identifiers
| Abbreviations =
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 1EQV5MLY3D
| InChI = 1/C2H7NO3S/c3-1-2-7(4,5)6/h1-3H2,(H,4,5,6)
| InChIKey = XOAAWQZATWQOTB-UHFFFAOYAA
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 239243
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C2H7NO3S/c3-1-2-7(4,5)6/h1-3H2,(H,4,5,6)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = XOAAWQZATWQOTB-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 107-35-7
| EINECS =
| PubChem = 1123
| IUPHAR_ligand = 2379
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 1091
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB01956
| SMILES = O=S(=O)(O)CCN
| RTECS =
| MeSHName =
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 15891
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00047
}}
|Section2={{Chembox Properties
| C=2 | H=7 | N=1 | O=3 | S=1
| MolarMass = 125.14 g/mol
| Appearance = colorless or white solid
| Density = 1.734&nbsp;g/cm<sup>3</sup> (at −173.15&nbsp;°C)
| MeltingPtC = 305.11
| MeltingPt_notes =Decomposes into simple molecules
| BoilingPt =
| BoilingPt_notes =
| Solubility =
| SolubleOther =
| Solvent =
| pKa = <0, 9.06
| pKb =
| IsoelectricPt =
| LambdaMax =
| Absorbance =
| SpecRotation =
| RefractIndex =
| Viscosity =
| Dipole = }}
|Section5={{Chembox Pharmacology
| AdminRoutes =
| Bioavail =
| Metabolism =
| HalfLife =
| ProteinBound =
| Excretion =
| Legal_status =
| Legal_US =
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| Pregnancy_category =
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 }}
| Section9 = {{Chembox Related
| OtherAnions =
| OtherCations =
| OtherFunction =
| OtherFunction_label =
| OtherCompounds = [[Sulfamic acid]]<br />[[Aminomethanesulfonic acid]]<br />[[Homotaurine]]
  }}
}}

'''Taurine''' ({{IPAc-en|audio=En-us-Taurine.ogg|ˈ|t|ɔː|r|iː|n}};<ref name="OLD">{{cite web |title=Oxford Learner's Dictionaries -- Taurine |url=https://www.oxfordlearnersdictionaries.com/definition/english/taurine |website=Oxford Learner's Dictionaries |publisher=Oxford University Press |archive-url=https://web.archive.org/web/20170628002042/https://www.oxfordlearnersdictionaries.com/definition/english/taurine |access-date=6 July 2025|archive-date=28 June 2017 }}</ref> IUPAC: '''2-aminoethanesulfonic acid'''<ref name="NCBI">{{cite web |title=Taurine |url=https://pubchem.ncbi.nlm.nih.gov/compound/1123 |website=National Center for Biotechnology Information |access-date=6 July 2025 |ref=NCBI}}</ref>) is a [[natural product|naturally occurring]] organic compound with the [[chemical formula]] {{chem2|C2H7NO3S}}, and is a [[Non-proteinogenic amino acids|non-proteinogenic]] [[sulfonic acid|amino sulfonic acid]] widely distributed in mammalian tissues and organs.<ref name="NCBI" /><ref name="SchullerLevis_2003">{{cite journal | vauthors = Schuller-Levis GB, Park E | title = Taurine: new implications for an old amino acid | journal = FEMS Microbiology Letters | volume = 226 | issue = 2 | pages = 195–202 | date = September 2003 | pmid = 14553911 |url=https://academic.oup.com/femsle/article-abstract/226/2/195/577328?redirectedFrom=fulltex | doi = 10.1016/S0378-1097(03)00611-6 | archive-url = https://web.archive.org/web/20241123145422/https://academic.oup.com/femsle/article-abstract/226/2/195/577328?redirectedFrom=fulltex | archive-date = 23 November 2024 | url-access = limited }}</ref> Structurally, by containing a [[sulfonic acid]] group instead of a [[carboxylic acid]] group, it is not involved in protein synthesis but is still usually referred to as an amino acid.<ref name="NCBI" /><ref name="Lehninger6th" >{{cite book  | last1 = Lehninger | first1 = Albert L.  | last2 = Nelson    | first2 = David L.  | last3 = Cox       | first3 = Michael M.  | title = Lehninger Principles of Biochemistry  | date = 2013  | publisher = W.H. Freeman  | location = New York  | isbn = 978-1-4292-3414-6  |edition=6th | page = 730  | url = https://archive.org/details/lehningerprincip0000lehn/page/730/mode/2up?q=Taurine | access-date = July 7, 2025  | via = Internet Archive }}</ref><ref name="FOBLML">{{cite book  | last1 = Voet      | first1 = Donald  | last2 = Voet      | first2 = Judith G.  | last3 = Pratt     | first3 = Charlotte W.  | title = Fundamentals of Biochemistry: Life at the Molecular Level | edition = 4th  | date = 2013 | publisher = John Wiley & Sons | isbn = 978-1-118-12918-0 | page = 86  | url = https://archive.org/details/FundamentalsBiochemistry4e_201802/page/n123/mode/2up?q=Taurine | access-date = July 7, 2025  | via = Internet Archive }}</ref><ref name="TDVME">{{cite book  | last = Hendler  | first = Sheldon Saul  | title = The Doctors' Vitamin and Mineral Encyclopedia  | date = 1990  | publisher = Simon & Schuster  | isbn = 978-0671667849  | page = 208  | url = https://archive.org/details/the-doctors-vitamin-and-mineral-encyclopedia/page/208/mode/2up?q=taurine  | access-date = July 7, 2025  | via = Internet Archive }}</ref> As non-proteinogenic amino sulfonic acid, it is not encoded by the [[genetic code]] and is distinguished from the protein-building [[Amino_acid#General_structure|α-amino acid]]s.<ref name="Lehninger8th">{{cite book |last1=Nelson |first1=David L. |last2=Cox |first2=Michael M. |title=Lehninger Principles of Biochemistry |date=2021 |publisher=W.H. Freeman |location=New York |isbn=978-1-319-22800-2 |edition=8th |page=866}}</ref>

Taurine is a major constituent of [[bile]] and can be found in the [[large intestine]]. <!--, and accounts for up to 0.1% of total human body weight.-->It is named after [[Latin]] {{wikt-lang|la|taurus}}, meaning [[bull]] or [[ox]], as it was first isolated from ox bile in 1827 by German scientists [[Friedrich Tiedemann]] and [[Leopold Gmelin]].

Although taurine is abundant in human organs, it is not an [[Essential nutrients|essential human dietary nutrient]] and is not included among nutrients with a [[Reference Daily Intake|recommended intake level]].<ref name="fda" /> Among the diverse pathways by which natural taurine can be biosynthesized, its human pathways (primarily in the human liver) are from [[cysteine]] and/or [[methionine]].<ref name="Ripps_2012" /><ref name="PubChem" />

Taurine is commonly sold as a [[dietary supplement]], but there is no good clinical evidence that taurine supplements provide any benefit to human health.<ref name="drugs">{{cite web | title = Taurine | date = 15 May 2023 | url = https://www.drugs.com/npp/taurine.html | publisher = Drugs.com | access-date = 26 August 2023 }}</ref> Taurine is used as a [[food additive]] to meet essential dietary intake levels for cats,<ref name=knopf/> and supplemental dietary support for dogs and poultry.<ref name="efsa" />

==Discovery and name==
Taurine was first isolated from ox bile in 1827 by German scientists [[Friedrich Tiedemann]] and [[Leopold Gmelin]].<ref name="Tiedemann_1827">{{cite journal |vauthors=Tiedemann F, Gmelin L |year=1827 |title=Einige neue Bestandtheile der Galle des Ochsen |url=https://zenodo.org/record/1423514 |journal=Annalen der Physik |volume=85 |issue=2 |pages=326–337 |bibcode=1827AnP....85..326T |doi=10.1002/andp.18270850214}}</ref><ref name="Huxtable">{{cite journal |vauthors=Huxtable RJ |date=January 1992 |title=Physiological actions of taurine |url=https://journals.physiology.org/doi/epdf/10.1152/physrev.1992.72.1.101 |journal=Physiological Reviews |volume=72 |issue=1 |pages=101–163 |doi=10.1152/physrev.1992.72.1.101 |pmid=1731369 |s2cid=27844955|url-access=subscription }}</ref> Another German scientist Von H. Demarcay first used its common chemical name Taurine in 1838, derived from the [[Latin]] {{wikt-lang|la|taurus}} ([[cognate]] to [[Ancient Greek]] {{wikt-lang| grc| ταῦρος}}, {{Transliteration|grc|taûros}}) meaning [[bull]] or [[ox]].<ref name="Demarcay">{{cite journal |last1=Demarcay |first1=H. |title=Ueber die natur der Galle |journal=Journal für Praktische Chemie |volume=15 |issue=1 |date=1838 |page=193-212 |doi=10.1002/prac.18380150118 |url=https://ia800805.us.archive.org/view_archive.php?archive=/13/items/crossref-pre-1909-scholarly-works/10.1002%252Fprac.18380140149.zip&file=10.1002%252Fprac.18380150118.pdf |access-date=7 July 2025}}</ref><ref name=":0">{{Cite journal |last1=Ripps |first1=Harris |last2=Shen |first2=Wen |date=2012 |title=Review: taurine: a "very essential" amino acid |journal=Molecular Vision |volume=18 |pages=2673–2686 |issn=1090-0535 |pmc=3501277 |pmid=23170060}}</ref><ref name="Huxtable" /> It was subsequently identified in human bile in 1846 by [[Edmund Ronalds]].<ref name="Ronalds_2019">{{cite journal |vauthors=Ronalds BF |date=2019 |title=Bringing Together Academic and Industrial Chemistry: Edmund Ronalds' Contribution |url=https://riviste.fupress.net/index.php/subs/article/view/211 |journal=Substantia |volume=3 |issue=1 |pages=139–152 |access-date=7 April 2025}}</ref>{{Better source needed|date=July 2025|reason=The current source has potential conflict of interest. Similar concern raised in April 2025. ([[WP:NOTRS]]).}}

==In nature==
Taurine is widely distributed in nature, particularly in animal tissues.<ref name="SchullerLevis_2003" />{{better source needed|reason=outdated lab research|date=April 2025}} Moreover, it is abundant in nature, including in animal organs,<ref name="Lambert_2004">{{cite journal | vauthors = Lambert IH | title = Regulation of the Cellular Content of the Organic Osmolyte Taurine in Mammalian Cells | journal = Neurochemical Research | volume = 29 | issue = 1 | pages = 27–63 | date = 2004 | pmid = 14992263 | doi = 10.1023/b:nere.0000010433.08577.96 }}</ref>{{better source needed|date=April 2025}}  and further, as substrates in the biosynthesis of [[bile salts]].<ref name="Ripps_2012">{{cite journal | vauthors = Ripps H, Shen W | title = Taurine: A "Very Essential" Amino Acid | journal = Molecular Vision | volume = 18 | pages = 2673–2686 | date = 12 November 2012 | pmid = 23170060 | pmc = 3501277 | format = review }}</ref> Taurine concentrations in human cells may derive from at least three processes:
* biosynthesis from the sulfur amino acids (e.g., cysteine);
* active uptake by a possible taurine transporter;{{medical citation needed|date=April 2025}} and
* the extent of its release from cells by a "volume-sensitive leak pathway".<ref name="Ripps_2012" />

It is not an [[Essential nutrient|essential human dietary nutrient]], resulting in the absence of taurine from compounds having a [[Reference Daily Intake]].<ref name="fda">{{cite web | title = Daily Value on the New Nutrition and Supplement Facts Labels | date = 25 February 2022 | url = https://www.fda.gov/food/new-nutrition-facts-label/daily-value-new-nutrition-and-supplement-facts-labels#referenceguide | archive-url = https://web.archive.org/web/20200614213640/https://www.fda.gov/food/new-nutrition-facts-label/daily-value-new-nutrition-and-supplement-facts-labels#referenceguide | url-status = dead | archive-date = June 14, 2020 | publisher = US Food and Drug Administration | access-date = 26 August 2023 }}</ref>  Its role in human physiology is unknown.

Taurine is a major constituent of [[bile]], and can be found in the [[large intestine]].{{citation needed|date=April 2025}} Its concentrations in [[land plants]] are low or undetectable, but up to a substantial wet weight has been found in [[algae]].<ref name="Kataoka_1986">{{cite journal | vauthors = Kataoka H, Ohnishi N | title = Occurrence of Taurine in Plants | journal = Agricultural and Biological Chemistry | volume = 50 | issue = 7 | pages = 1887–1888 | date = 1986 | doi = 10.1271/bbb1961.50.1887 | url = https://www.jstage.jst.go.jp/article/bbb1961/50/7/50_7_1887/_article | doi-access = free }}</ref><ref name="McCusker_2014">{{cite journal | vauthors = McCusker S, Buff PR, Yu Z, Fascetti AJ | title = Amino acid content of selected plant, algae and insect species: a search for alternative protein sources for use in pet foods | journal = Journal of Nutritional Science | volume = 3 | article-number = e39 | date = 2014 | pmid = 26101608 | pmc = 4473169 | doi = 10.1017/jns.2014.33 | language = en | issn = 2048-6790 }}</ref>

==Chemical and biochemical features==
Taurine exists as a [[zwitterion]] {{chem2|H3N+CH2CH2SO3-}}, as verified by [[X-ray crystallography]].<ref>{{cite journal | vauthors = Görbitz CH, Prydz K, Ugland S | title = Taurine | journal = Acta Crystallographica Section C | volume = 56 | issue = 1 | pages = e23–e24 | year = 2000 | doi = 10.1107/S0108270199016029 | bibcode = 2000AcCrC..56E..23G }}</ref> The sulfonic acid has a low [[pKa|p''K''<sub>a</sub>]]<ref>{{cite journal | vauthors = Irving CS, Hammer BE, Danyluk SS, Klein PD | title = 13C nuclear magnetic resonance study of the complexation of calcium by taurine | journal = Journal of Inorganic Biochemistry | volume = 13 | issue = 2 | pages = 137–150 | date = October 1980 | pmid = 7431022 | doi = 10.1016/S0162-0134(00)80117-8 }}</ref> ensuring that it is fully [[ionized]] to the [[sulfonate]] at the [[pH]]s found in the intestinal tract.

===Biosynthesis===
Among the diverse pathways by which natural taurine can be biosynthesized, its pathways in the human liver are from [[cysteine]] and/or [[methionine]].<ref name="Ripps_2012" /><ref name = PubChem>{{cite web | title = Taurine | date = 25 May 2024 | url = https://pubchem.ncbi.nlm.nih.gov/compound/Taurine | publisher = PubChem, US National Library of Medicine | accessdate = 31 May 2024 }}</ref> With regard to the route from [[cysteine]]: mammalian taurine synthesis occurs in the [[liver]] via the [[cysteine sulfinic acid]] pathway. In this pathway, [[cysteine]] is first oxidized to its sulfinic acid, catalyzed by the enzyme [[cysteine dioxygenase]]. Cysteine sulfinic acid, in turn, is [[Decarboxylation|decarboxylated]] by [[sulfinoalanine decarboxylase]] to form [[hypotaurine]]. Hypotaurine is enzymatically oxidized to yield taurine by [[hypotaurine dehydrogenase]].<ref>{{cite journal | vauthors = Sumizu K | title = Oxidation of hypotaurine in rat liver | journal = Biochimica et Biophysica Acta | volume = 63 | pages = 210–212 | date = September 1962 | pmid = 13979247 | doi = 10.1016/0006-3002(62)90357-8 }}</ref>

Taurine is also produced by the [[transsulfuration pathway]], which converts [[homocysteine]] into [[cystathionine]]. The cystathionine is then converted to [[hypotaurine]] by the sequential action of three enzymes: [[cystathionine gamma-lyase]], [[cysteine dioxygenase]], and cysteine sulfinic acid decarboxylase. Hypotaurine is then oxidized to taurine as described above.<ref>{{cite journal | vauthors = Ripps H, Shen W | title = Review: taurine: a "very essential" amino acid | journal = Molecular Vision | volume = 18 | pages = 2673–2686 | date = 2012 | pmid = 23170060 | pmc = 3501277 }}</ref>

A pathway for taurine biosynthesis from [[serine]] and [[sulfate]] is reported in [[microalgae]],<ref name="McCusker_2014" /> developing [[chicken]] [[embryo]]s,<ref>{{cite journal | vauthors = Machlin LJ, Pearson PB, Denton CA | title = The Utilization of Sulfate Sulfur for the Synthesis of Taurine in the Developing Chick Embryo | journal = The Journal of Biological Chemistry | volume = 212 | issue = 1 | pages = 469–475 | date = 1955 | pmid = 13233249 | doi = 10.1016/s0021-9258(18)71134-4 | issn = 0021-9258 | doi-access = free }}</ref> and chick [[liver]].<ref>{{cite journal | vauthors = Sass NL, Martin WG | title = The Synthesis of Taurine from Sulfate III. Further Evidence for the Enzymatic Pathway in Chick Liver | journal = Proceedings of the Society for Experimental Biology and Medicine | volume = 139 | issue = 3 | pages = 755–761 | date = 1972-03-01 | pmid = 5023763 | doi = 10.3181/00379727-139-36232 | url = http://ebm.sagepub.com/lookup/doi/10.3181/00379727-139-36232 | language = en | s2cid = 77903 | issn = 1535-3702 | url-access = subscription }}</ref> Serine dehydratase converts serine to [[2-aminoacrylate]], which is converted to [[cysteic acid]] by [[3'-phosphoadenylyl sulfate|3{{prime}}-phosphoadenylyl sulfate]]:2-aminoacrylate ''C''-[[sulfotransferase]]. Cysteic acid is converted to taurine by cysteine [[sulfinic acid]] [[decarboxylase]].
[[File:Degradation of Cysteine to Taurine.svg|class=skin-invert-image|thumb|center|800px|alt=reaction diagram|Oxidative degradation of cysteine to taurine]]

===Chemical synthesis===
Synthetic taurine is obtained by the [[ammonolysis]] of [[isethionic acid]] (2-hydroxyethanesulfonic acid), which in turn is obtained from the reaction of [[ethylene oxide]] with aqueous [[sodium bisulfite]]. A direct approach involves the reaction of [[aziridine]] with [[sulfurous acid]].<ref>{{Ullmann | vauthors = Kosswig K |title=Sulfonic Acids, Aliphatic|year=2000|doi=10.1002/14356007.a25_503|isbn=978-3-527-30673-2}}</ref>

In 1993, about {{val|5000|–|6000|u=[[tonnes]]}} of taurine were produced for commercial purposes: 50% for pet food and 50% in pharmaceutical applications.<ref name="kirk">{{cite book | veditors = PS T | chapter = Sulfonic Acids | title = Kirk-Othmer Encyclopedia of Chemical Technology | year = 2000 | doi = 10.1002/0471238961.1921120620211212.a01 | publisher = John Wiley & Sons, Inc | isbn = 978-0-471-23896-6 | last1 = Tully | first1 = Paul S. }}</ref>

In the laboratory, taurine can be produced by [[alkylation]] of ammonia with bromoethanesulfonate salts.<ref>{{cite journal | vauthors = Marvel CS, Bailey CF, Cortese F | title = Taurine | journal = Organic Syntheses | volume = 18 | pages = 77 | year = 1938 | doi = 10.15227/orgsyn.018.0077 }}</ref>{{update inline| date=January 2025| ?=yes |reason=Source is from 1938. Are there any newer syntheses that are used?}}

==In food==
Taurine occurs naturally in fish and meat.<ref name="drugs" /><ref name=Brosnan2006>{{cite journal | vauthors = Brosnan JT, Brosnan ME | title = The sulfur-containing amino acids: an overview | journal = The Journal of Nutrition | volume = 136 | issue = 6 Suppl | pages = 1636S–1640S | date = June 2006 | pmid = 16702333 | doi = 10.1093/jn/136.6.1636S | doi-access = free }}</ref><ref name="Huxtable" /> The mean daily intake from omnivore diets was determined to be around {{val|58|u=mg}} (range {{val|9|–|372|u=mg}}),<ref name="ref9">{{cite web | title = Opinion on Caffeine, Taurine and <small>D</small>-Glucurono&nbsp;–γ-Lactone as constituents of so-called 'energy' drinks | date = 1999-01-21 | publisher = Directorate-General Health and Consumers, European Commission, European Union | url = http://ec.europa.eu/food/fs/sc/scf/out22_en.html | archive-url = https://web.archive.org/web/20060623112948/http://ec.europa.eu/food/fs/sc/scf/out22_en.html | archive-date = 2006-06-23 }}</ref> and to be low or negligible from a [[vegan diet]].<ref name="drugs" /> Typical taurine consumption in the [[American diet]] is about {{val|123|-|178|u=mg}} per day.<ref name="drugs" />

Taurine is partially destroyed by heat in processes such as baking and boiling. This is a concern for cat food, as cats have a dietary requirement for taurine and can easily become deficient. Either [[raw feeding]] or supplementing taurine can satisfy this requirement.<ref>{{cite journal | vauthors = Jacobson SG, Kemp CM, Borruat FX, Chaitin MH, Faulkner DJ | title = Rhodopsin topography and rod-mediated function in cats with the retinal degeneration of taurine deficiency | journal = Experimental Eye Research | volume = 45 | issue = 4 | pages = 481–490 | date = October 1987 | pmid = 3428381 | doi = 10.1016/S0014-4835(87)80059-3 }}</ref><ref>{{cite journal | vauthors = Spitze AR, Wong DL, Rogers QR, Fascetti AJ | title = Taurine concentrations in animal feed ingredients; cooking influences taurine content | journal = Journal of Animal Physiology and Animal Nutrition | volume = 87 | issue = 7–8 | pages = 251–262 | date = Aug 2003 | pmid = 12864905 | doi = 10.1046/j.1439-0396.2003.00434.x | url = https://www.vetmed.ucdavis.edu/sites/g/files/dgvnsk491/files/aal/pdfs/spitze.pdf | accessdate = January 27, 2024 }}</ref>

Both [[lysine]] and taurine can mask the metallic flavor of [[potassium chloride]], a salt substitute.<ref>{{cite journal | vauthors = dos Santos BA, Campagnol PC, Morgano MA, Pollonio MA | title = Monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine improve the sensory quality of fermented cooked sausages with 50% and 75% replacement of NaCl with KCl | journal = Meat Science | volume = 96 | issue = 1 | pages = 509–513 | date = January 2014 | pmid = 24008059 | doi = 10.1016/j.meatsci.2013.08.024 }}</ref>

===Breast milk===
Taurine is present in [[breast milk]], and has been added to many [[infant formula]]s as a measure of prudence since the early 1980s. However, this practice has never been rigorously studied, and as such it has yet to be proven to be necessary, or even beneficial.<ref>{{cite journal | vauthors = Heird WC | title = Taurine in neonatal nutrition – revisited | journal = Archives of Disease in Childhood. Fetal and Neonatal Edition | volume = 89 | issue = 6 | pages = F473–F474 | date = November 2004 | pmid = 15499132 | pmc = 1721777 | doi = 10.1136/adc.2004.055095 }}</ref>

===Energy drinks and dietary supplements===
Taurine is an ingredient in some [[energy drink]]s in amounts of {{val|1|–|3|u=grams}} per serving.<ref name="drugs" /><ref>{{cite journal | vauthors = Kurtz JA, VanDusseldorp TA, Doyle JA, Otis, JS | title = Taurine in sports and exercise | journal = Journal of the International Society of Sports Nutrition | volume = 18 | issue = 1 | article-number = 39 | date = May 2021 | pmid = 34039357 | pmc = 8152067 | doi = 10.1186/s12970-021-00438-0 | doi-access = free }}</ref>

==Research==
Taurine is not regarded as an [[essential nutrient|essential human dietary nutrient]] and has not been assigned recommended intake levels.<ref name="fda" /> High-quality clinical studies to determine possible effects of taurine in the body or following dietary supplementation are absent from the literature.<ref name="drugs" /> Preliminary human studies on the possible effects of taurine supplementation have been inadequate due to low subject numbers, inconsistent designs, and variable doses.<ref name="drugs" />

==Safety and toxicity==
According to the [[European Food Safety Authority]], taurine is "considered to be a skin and eye irritant and skin sensitiser, and to be hazardous if inhaled"; it may be safe to consume up to 6&nbsp;grams of taurine per day.<ref name="efsa">{{cite journal | author = EFSA Panel on Additives and Products or Substances used in Animal Feed | title = Scientific Opinion on the safety and efficacy of taurine as a feed additive for all animal species | journal = EFSA Journal | volume = 10 | issue = 6 | pages = 2736 | date = 2012 | doi = 10.2903/j.efsa.2012.2736 | doi-access = free }}</ref> Other sources indicate that taurine is safe for supplemental intake in normal healthy adults at up to 3&nbsp;grams per day.<ref name="drugs" /><ref name="pmid18325648">{{cite journal | vauthors = Shao A, Hathcock JN | title = Risk assessment for the amino acids taurine, <small>L</small>-glutamine and <small>L</small>-arginine | journal = Regulatory Toxicology and Pharmacology | volume = 50 | issue = 3 | pages = 376–399 | date = April 2008 | pmid = 18325648 | doi = 10.1016/j.yrtph.2008.01.004 | quote = the newer method described as the Observed Safe Level (OSL) or Highest Observed Intake (HOI) was utilized. The OSL risk assessments indicate that based on the available published human clinical trial data, the evidence for the absence of adverse effects is strong for taurine at supplemental intakes up to 3&nbsp;g/day, [[glutamine]] at intakes up to 14&nbsp;g/day and [[arginine]] at intakes up to 20&nbsp;g/day, and these levels are identified as the respective OSLs for normal healthy adults. }}</ref>

A 2008 review found no documented reports of negative or positive health effects associated with the amount of taurine used in energy drinks, concluding, "The amounts of [[guarana]], taurine, and [[ginseng]] found in popular energy drinks are far below the amounts expected to deliver either therapeutic benefits or adverse events".<ref>{{cite journal | vauthors = Clauson KA, Shields KM, McQueen CE, Persad N | title = Safety issues associated with commercially available energy drinks | journal = Journal of the American Pharmacists Association | volume = 48 | issue = 3 | pages = e55–63; quiz e64–7 | year = 2008 | pmid = 18595815 | doi = 10.1331/JAPhA.2008.07055 | s2cid = 207262028 }}</ref>

==Animal dietary requirement==
=== Cats ===
[[Cats]] lack the enzyme [[sulfinoalanine decarboxylase]] to produce taurine and must therefore acquire it from their diet.<ref name="knopf">{{cite journal | vauthors = Knopf K, Sturman JA, Armstrong M, Hayes KC | title = Taurine: an essential nutrient for the cat | journal = The Journal of Nutrition | volume = 108 | issue = 5 | pages = 773–778 | date = May 1978 | pmid = 641594 | doi = 10.1093/jn/108.5.773 | url = https://www.researchgate.net/publication/22499901 }}</ref> A taurine deficiency in cats can lead to retinal degeneration and eventually blindness ‒ a condition known as ''[[Macular degeneration|central retinal degeneration]]'',<ref>{{cite journal | vauthors = Hayes KC, Carey RE, Schmidt SY | title = Retinal Degeneration Associated with Taurine Deficiency in the Cat | journal = Science | location = New York, N.Y. | volume = 188 | issue = 4191 | pages = 949–951 | date = 1975 | pmid = 1138364 | doi = 10.1126/science.1138364 | url = https://www.science.org/doi/abs/10.1126/science.1138364 | bibcode = 1975Sci...188..949H | url-access = subscription }}</ref><ref>{{cite book | title = Nutrient Requirements of Cats, Revised Edition | date = 1986 | publisher = Board On Agriculture | isbn = 978-0-309-07483-4 }}</ref> as well as hair loss and tooth decay. Other effects of a diet lacking in taurine are dilated [[cardiomyopathy]]<ref name="Hayes_1975">{{cite journal | vauthors = Hayes KC, Carey RE, Schmidt SY | title = Retinal degeneration associated with taurine deficiency in the cat | journal = Science | location = New York, N.Y. | volume = 188 | issue = 4191 | pages = 949–951 | date = May 1975 | pmid = 1138364 | doi = 10.1126/science.1138364 | bibcode = 1975Sci...188..949H }}</ref> and reproductive failure in female cats.<ref name="knopf" /><ref>{{Cite journal |last1=Morris |first1=J. G. |last2=Rogers |first2=Q. R. |last3=Pacioretty |first3=L. M. |date=1990 |title=Taurine: an essential nutrient for cats |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1748-5827.1990.tb00672.x |journal=Journal of Small Animal Practice |language=en |volume=31 |issue=10 |pages=502–509 |doi=10.1111/j.1748-5827.1990.tb00672.x |issn=1748-5827|url-access=subscription }}</ref>

Decreased plasma taurine concentration has been demonstrated to be associated with [[feline dilated cardiomyopathy]]. Unlike central retinal degeneration, the heart condition is reversible with supplementation.<ref>{{cite journal | vauthors = Pion PD, Kittleson MD, Rogers QR, Morris JG | title = Myocardial failure in cats associated with low plasma taurine: a reversible cardiomyopathy | journal = Science | location = New York, N.Y. | volume = 237 | issue = 4816 | pages = 764–768 | date = August 1987 | pmid = 3616607 | doi = 10.1126/science.3616607 | bibcode = 1987Sci...237..764P }}</ref>

Taurine is now a requirement of the [[Association of American Feed Control Officials]] (AAFCO) and any dry or wet food product labeled approved by the AAFCO should have a minimum of 0.1% taurine in dry food and 0.2% in wet food.<ref>{{cite web | title = AAFCO Cat Food Nutrient Profiles | url = http://maxshouse.com/nutrition/aafco_cat_food_nutrient_profiles.htm | access-date = 30 May 2015 | archive-url = https://web.archive.org/web/20150529172000/http://maxshouse.com/nutrition/aafco_cat_food_nutrient_profiles.htm | archive-date = 2015-05-29 }}</ref> Studies suggest the amino acid should be supplied at {{val|10|u=mg|up=kg}} of bodyweight per day for domestic cats.<ref>{{cite journal | vauthors = Burger IH, Barnett KC | title = The taurine requirement of the adult cat | journal = Journal of Small Animal Practice | volume = 23 | issue = 9 | pages = 533–537 | year = 1982 | doi = 10.1111/j.1748-5827.1982.tb02514.x }}</ref>

=== Other mammals ===
A number of other mammals also have a requirement for taurine. While the majority of dogs can synthesize taurine, case reports have described a singular [[American cocker spaniel]], 19 [[Newfoundland dog]]s, and a family of [[golden retriever]]s suffering from taurine deficiency treatable with supplementation. [[Fox]]es on [[fur farm]]s also appear to require dietary taurine. The [[rhesus monkey|rhesus]], [[cebus]] and [[cynomolgus]] monkeys each require taurine at least in infancy.<!-- Do I try to stress that this does not apply to human infants here? Them monkeys were fed taurine-free human infant formula, something humans are perfectly okay with. --> The [[giant anteater]] also requires taurine.<ref>{{cite journal | vauthors = Schaffer SW, Ito T, Azuma J | title = Clinical significance of taurine | journal = Amino Acids | volume = 46 | issue = 1 | pages = 1–5 | date = January 2014 | pmid = 24337931 | doi = 10.1007/s00726-013-1632-8 }} (abstracts of animal citations used to provide list of species)</ref>

=== Birds ===
Taurine appears to be essential for the development of [[passerine]] birds. Many passerines seek out taurine-rich [[spider]]s to feed their young, particularly just after hatching. Researchers compared the behaviours and development of birds fed a taurine-supplemented diet to a control diet and found the juveniles fed taurine-rich diets as neonates were much larger risk takers and more adept at spatial learning tasks. Under natural conditions, each [[blue tit]] nestling receive {{val|1|u=mg}} of taurine per day from parents.<ref name="Arnold_2007">{{cite journal | vauthors = Arnold KE, Ramsay SL, Donaldson C, Adam A | title = Parental prey selection affects risk-taking behaviour and spatial learning in avian offspring | journal = Proceedings. Biological Sciences | volume = 274 | issue = 1625 | pages = 2563–2569 | date = October 2007 | pmid = 17698490 | pmc = 2275882 | doi = 10.1098/rspb.2007.0687 }}</ref>

Taurine can be synthesized by chickens. Supplementation has no effect on chickens raised under adequate lab conditions, but seems to help with growth under stresses such as heat and dense housing.<ref>{{cite journal | vauthors = Surai P, Kochish I, Kidd M | title = Taurine in poultry nutrition | journal = Animal Feed Science and Technology | volume = 260 | article-number = 114339 | date = February 2020 | doi = 10.1016/j.anifeedsci.2019.114339 | s2cid = 209599794 }}</ref>

=== Fish ===
Species of fish, mostly carnivorous ones, show reduced growth and survival when the fish-based feed in their food is replaced with soy meal or feather meal. Taurine has been identified as the factor responsible for this phenomenon; supplementation of taurine to plant-based fish feed reverses these effects. Future aquaculture is expected to use more of these more environmentally-friendly protein sources, so supplementation would become more important.<ref>{{cite journal | vauthors = Salze GP, Davis DA | title = Taurine: a critical nutrient for future fish feeds | journal = Aquaculture | volume = 437 | pages = 215–229 | date = February 2015 | doi = 10.1016/j.aquaculture.2014.12.006 | doi-access = free | bibcode = 2015Aquac.437..215S }}</ref>

The need of taurine in fish is conditional, differing by species and growth stage. The [[olive flounder]], for example, has lower capacity to synthesize taurine compared to the [[rainbow trout]]. Juvenile fish are less efficient at taurine biosyntheis due to reduced [[cysteine sulfinate decarboxylase]] levels.<ref>{{cite journal | vauthors = Sampath WW, Rathnayake RM, Yang M, Zhang W, Mai K | title = Roles of dietary taurine in fish nutrition | journal = Marine Life Science & Technology | volume = 2 | issue = 4 | pages = 360–375 | date = November 2020 | doi = 10.1007/s42995-020-00051-1 | bibcode = 2020MLST....2..360S | url = https://www.researchgate.net/publication/343025001 }}</ref>

==Derivatives==
{{see also|Derivative (chemistry)}}
* Taurine is used in the preparation of the [[anthelmintic]] drug, Totabin{{medical citation needed|date=April 2025}}
* [[Taurolidine]]
* [[Taurocholic acid]] and [[tauroselcholic acid]]
* Tauromustine
* 5-Taurinomethyluridine and 5-taurinomethyl-2-thiouridine are modified [[uridine]]s in (human) mitochondrial [[transfer RNA|tRNA]].<ref>{{cite journal | vauthors = Suzuki T, Suzuki T, Wada T, Saigo K, Watanabe K | title = Taurine as a constituent of mitochondrial tRNAs: new insights into the functions of taurine and human mitochondrial diseases | journal = The EMBO Journal | volume = 21 | issue = 23 | pages = 6581–6589 | date = December 2002 | pmid = 12456664 | pmc = 136959 | doi = 10.1093/emboj/cdf656 }}</ref>
* ''Tauryl'' is the [[functional group]] attaching at the sulfur, 2-aminoethylsulfonyl.<ref>{{cite book | vauthors = Bünzli-Trepp U | title = Systematic nomenclature of organic, organometallic and coordination chemistry | pages = 226 | year = 2007 | publisher = EPFL Press | isbn = 978-1-4200-4615-1 }}</ref>
* ''Taurino'' is the functional group attaching at the nitrogen, 2-sulfoethylamino.
* [[Thiotaurine]]
* [[Peroxytaurine]] which is a degradation product by both [[superoxide]] and heat degradation.

== See also ==
{{Portal|Medicine}}
* [[Homotaurine]] (tramiprosate), precursor to [[acamprosate]]
* [[Taurates]], a group of surfactants

== References ==
{{Reflist}}
{{Dietary supplement}}
{{Neurotransmitters}}
{{Glycine receptor modulators}}

{{Authority control}}

[[Category:Aminoethyl compounds]]
[[Category:Sulfonic acids]]
[[Category:Glycine receptor agonists]]
[[Category:Inhibitory amino acids]]