In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Dictionary of Cancer Terms

Page Options

  • Print This Page

Widget



International Unit  listen  (IN-ter-NA-shuh-nul YOO-nit)

  A unit used to measure the activity of many vitamins, hormones, enzymes, and drugs. An International Unit is the amount of a substance that has a certain biological effect. For each substance there is an international agreement on the biological effect that is expected for 1 International Unit. Also called IU.