Back ميكروغرام Arabic Microgramu AST माइक्रोग्राम Bihari Mikrogram BS Microgram Catalan Mikrogram Danish Mikrogramm German Microgramo Spanish Mikrogramo Basque میکروگرم Persian
| Microgram | |
|---|---|
 A nutrition facts label displaying, for example, the amount of folic acid in micrograms | |
| General information | |
| Unit system | SI |
| Unit of | mass |
| Symbol | μg |
In the metric system, a microgram or microgramme is a unit of mass equal to one millionth (1×10−6) 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). However, mcg is preferred for medical information in the United States (US) and United Kingdom. A third abbreviation, the Greek letter γ (gamma), is no longer recommended.[1]
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.[2] This is due to the risk that μ might be misread as m, for "milli-", which is equal to one thousandth (1×10−3). 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 to10 μg.