Microgram

Template:Short description Template:Hatnote Template:Infobox unit In the metric system, a microgram or microgramme is a unit of mass equal to one millionth (Template:Val) of a gram. Two different abbreviations are commonly used. The International System of Units (SI) uses μg, where the SI prefix "micro-" is represented by the Greek letter μ (mu). The abbreviation mcg is preferred for medical information in the United States (US), but prescription writing guidance in the United Kingdom advises that "microgram" should not be abbreviated.<ref>Template:Cite web</ref> A third abbreviation, the Greek letter γ (gamma), is no longer recommended.<ref>NIST Handbook 133 - 2018, Appendix E. General Tables of Units of Measurement, page 159 (17)</ref> The US Institute for Safe Medication Practices (ISMP) and the US Food and Drug Administration (FDA) recommend that mcg should be used, rather than μg, when communicating medical information.<ref>Template:Cite web</ref> This is due to the risk that μ might be misread as m, for "milli-", which is equal to one thousandth (Template:Val). Such a misreading could result in a thousandfold overdose of a drug or medicine. However, mcg is also the symbol for the obsolete unit millicentigram, derived from the centimetre–gram–second system of units and equal to 10 μg.

Typography

Usually, a sequence of the Unicode code point Template:Unichar followed by the Latin letter Template:Unichar should be used. However, if μ is not available it may be represented with Template:Unichar or the legacy Unicode symbol Template:Unichar. In Chinese, Japanese and Korean writing a fullwidth version Template:Unichar should be used.<ref name="Unicode-U3300">Template:Cite web</ref>

See also

• List of SI prefixes
• Orders of magnitude (mass), listing a few items that have a mass of around 1 μg.