Micrograms (mcg) is a unit of mass which is equal to one millionth of a gram, abbreviated as μg. This unit of measurement is used to quantify substances or particles, often too small to be measured in larger units of measurement. It is commonly used in scientific research, especially in studies related to pharmaceuticals, or other measurements where precision is especially important. In some cases, it might be necessary to measure extremely tiny amounts to ensure that the data is accurate and representative of the subject at hand. Measuring in mcg allows researchers to control and understand the relative amounts of various substances, without having to use larger measurements that would be more difficult to manage or reflect inaccurately.