What is IC50?
{{complex|date=December 2023}} The '''IC<sub>50</sub>''' is a measure of how effective a [[drug]] is. It indicates how much of a particular drug or other substance is needed to [[Inhibitor|inhibit]] a given biological process (or component of a process, i.e. an [[enzyme]], [[cell (biology)|cell]], [[cell receptor]] or [[microorganism]]) by half. In other words, it is the half minimal (50%) inhibitory concentration (IC) of a substance (50% IC, or IC<sub>50</sub>). It is commonly used as a measure of [[Receptor antagonists|antagonist drug]] [[potency]] in [[Pharmacology|pharmacological]] research. Sometimes, it is also converted to the '''pIC<sub>50</sub>''' scale (-log IC<sub>50</sub>), in which higher values indicate exponentially greater potency. According to the [[Food and Drug Administration|FDA]], IC<sub>50</sub> represents the concentration of a drug that is required for 50% inhibition [[in vitro]].<ref name=fda>{{Cite web |url=http://www.fda.gov/ohrms/dockets/ac/00/slides/3621s1d/sld036.htm |title=IC50 versus EC50<!-- Bot generated title --> |website=[[Food and Drug Administration]] |access-date=2008-02-11 |archive-date=2011-02-06 |archive-url=https://web.archive.org/web/20110206042604/http://www.fda.gov/ohrms/dockets/ac/00/slides/3621s1d/sld036.htm |url-status=dead }}</ref> It is comparable to an [[half maximal effective concentration|EC<sub>50</sub>]] for [[agonist|agonist drugs]]. EC<sub>50</sub> also represents the plasma concentration required for obtaining 50% of a maximum effect ''[[in vivo]]''.<ref name=fda/> ==References== {{reflist}} {{med-stub}} [[Category:Chemistry]]