Editing Microgram

{{Short description|Unit of mass, 1 millionth of a gram}}
{{Hatnote|"μg" and "ΜG" (Greek letter mu with G) redirect here. For microgravity, see [[micro-g environment]]. Not to be confused with [[MG (disambiguation)|MG]] (in Latin letters) or [[uG (disambiguation)|uG]] (in Latin letters).}}
{{Infobox unit
| name         = Microgram
| image        = Radiance multivitamins nutritional information crop.jpg
| caption      = A [[nutrition facts label]] displaying, for example, the amount of [[folic acid]] in micrograms
| standard     = [[International System of Units|SI]]
| quantity     = [[mass]]
| symbol       = μg
}}
In the [[metric system]], a '''microgram''' or '''microgramme''' is a [[Physical unit|unit]] of [[mass]] equal to one millionth ({{val|1|e=-6}}) of a [[gram]]. The unit symbol is '''μg''' according to the [[International System of Units]] (SI); the recommended symbol in the United States and United Kingdom when communicating medical information is '''mcg'''.  In μg, the prefix symbol for [[micro-]] is the Greek letter [[Mu (letter)|μ (mu)]].

==Abbreviation and symbol confusion==
When the Greek lowercase "μ" (mu) is typographically unavailable, it is occasionally – although not properly {{Citation needed|reason=Considered "not properly" by whom?|date=September 2024}} – replaced by the Latin lowercase "u". 

The United States–based [[Institute for Safe Medication Practices]] (ISMP) and the U.S. [[Food and Drug Administration]] (FDA) recommend that the symbol μg should not be used when communicating medical information due to the risk that the prefix [[micro-|μ (micro-)]] might be misread as the prefix [[milli-|m (milli-)]], resulting in a thousandfold overdose. The ISMP recommends the non-[[International System of Units|SI]] symbol '''mcg''' instead.<ref>{{cite web
|url=https://www.ismp.org/recommendations/error-prone-abbreviations-list
|title=ISMP's List of Error-Prone Abbreviations, Symbols, and Dose Designations
|access-date=2018-03-28
|publisher=ISMP}}</ref> However, the abbreviation mcg is also the symbol for an obsolete [[CGS|centimetre–gram–second system of units]] unit of measure known as millicentigram, which is equal to 10&nbsp;μg.

Gamma (symbol: [[γ]]) is a deprecated non-SI unit of [[mass]] equal to 1 μg.<ref>[https://www.nist.gov/pml/weights-and-measures/publications/nist-handbooks/handbook-133 NIST Handbook 133 - 2018], [https://www.nist.gov/sites/default/files/documents/2017/04/28/12-apde-gentab-11-hb133-final.pdf#page=17 Appendix E. General Tables of Units of Measurement, page 159 (17)]</ref>

A [[fullwidth]] version of the "microgram" symbol is encoded by [[Unicode]] at code point {{unichar|338D|Square Mu G}} for use in [[CJK characters|CJK]] contexts.<ref name="Unicode-U3300">{{cite web |url=https://www.unicode.org/charts/PDF/U3300.pdf |access-date=May 24, 2019 |title=The Unicode Standard 12.0 – CJK Compatibility ❰ Range: 3300—33FF ❱ |author=Unicode Consortium |author-link=Unicode Consortium |date=2019 |website=Unicode.org}}</ref> In other contexts, a sequence of the Greek letter [[Mu (letter)|mu]] (U+03BC) and Latin letter g (U+0067) should be used.

==See also==
{{wiktionary|microgram|μg|mcg}}
* [[Metric prefix#List of SI prefixes|List of SI prefixes]]
* [[Orders of magnitude (mass)#10−12 to 10−6 kg|Orders of magnitude (mass)]], listing a few items that have a mass of around 1 μg.

==References==
{{reflist}}

[[Category:SI derived units]]
[[Category:Units of mass]]