Editing Median lethal dose (section)

{{Short description|Measurement of lethal dose of substance}}
{{redirect|LD50}}
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In [[toxicology]], the '''median lethal dose''', '''LD<sub>50</sub>''' (abbreviation for "[[lethal dose]], 50%"), '''LC<sub>50</sub>''' (lethal concentration, 50%) or '''LCt<sub>50</sub>''' is a [[toxic unit]] that measures the [[lethal dose]] of a given [[Chemical substance|substance]].<ref>{{Cite web|url=https://goldbook.iupac.org/html/A/A00025.html|work=IUPAC Gold Book|title=Absolute lethal dose (LD100)|publisher=International Union of Pure and Applied Chemistry|language=en|access-date=2019-07-01|archive-url=https://web.archive.org/web/20190701134347/https://goldbook.iupac.org/html/A/A00025.html|archive-date=2019-07-01|url-status=dead}}</ref> The value of LD<sub>50</sub> for a substance is the [[Dose (pharmacology)|dose]] required to kill half the members of a tested population after a specified test duration. LD<sub>50</sub> figures are frequently used as a general indicator of a substance's [[acute toxicity]]. A lower LD<sub>50</sub> is indicative of higher toxicity.

The term LD<sub>50</sub> is generally attributed to John William Trevan.<ref name="Biographical Memoirs of Fellows of the Royal Society 1957 pp. 273–288">{{cite journal | title=John William Trevan, 1887-1956 | journal=Biographical Memoirs of Fellows of the Royal Society | volume=3 | date=1957 | issn=0080-4606 | doi=10.1098/rsbm.1957.0019 | pages=273–288 | url=https://royalsocietypublishing.org/doi/pdf/10.1098/rsbm.1957.0019 | access-date=2024-03-31 | archive-date=2020-03-28 | archive-url=https://web.archive.org/web/20200328170611/https://royalsocietypublishing.org/doi/pdf/10.1098/rsbm.1957.0019 | url-status=live | url-access=subscription }}</ref> The test was created by J. W. Trevan in 1927.<ref>{{cite web|url=http://www.ccohs.ca/oshanswers/chemicals/ld50.html|title=What is a LD50 and LC50?|work=OSH Answers Fact Sheets|date=5 October 2021|publisher=Canadian Centre for Occupational Health and Safety|access-date=15 July 2006|archive-date=26 June 2015|archive-url=https://web.archive.org/web/20150626013647/http://www.ccohs.ca/oshanswers/chemicals/ld50.html|url-status=live}}</ref> The term '''semilethal dose''' is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD<sub>50</sub> is usually determined by tests on animals such as [[Laboratory mouse|laboratory mice]]. In 2011, the U.S. [[Food and Drug Administration]] approved alternative methods to LD<sub>50</sub> for testing the cosmetic drug [[botox]] without animal tests.<ref>{{cite web
 |date=24 June 2011 
 |title=Allergan Receives FDA Approval for First-of-Its-Kind, Fully in vitro, Cell-Based Assay for BOTOX and BOTOX Cosmetic (onabotulinumtoxinA) 
 |publisher=Allergan Web site 
 |url=http://agn.client.shareholder.com/releasedetail.cfm?ReleaseID=587234 
 |access-date=2012-08-15 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20110626185759/http://agn.client.shareholder.com/releasedetail.cfm?ReleaseID=587234 
 |archive-date=26 June 2011 
}}</ref><ref>{{cite news | vauthors = Gaul GM | date = 12 April 2008 | title = In U.S., Few Alternatives To Testing On Animals | newspaper = [[Washington Post]] | url = https://www.washingtonpost.com/wp-dyn/content/article/2008/04/11/AR2008041103733.html | access-date = 2011-06-26 | archive-date = 2012-11-12 | archive-url = https://web.archive.org/web/20121112163835/http://www.washingtonpost.com/wp-dyn/content/article/2008/04/11/AR2008041103733.html | url-status = live }}</ref>