International Unit

Insulin Vials

Reading about some drugs (Invega, Depakote & Zyprexa), I find that dosage is given in "mIU/L" which means milli-International Units per Liter. Milli- and Liter I understand, but what is this International Unit? The only time I can remember running across this before is with insulin, I think. Isn't insulin measured in International Units?

International Unit is a term used by people in the medical industrial complex to tell themselves something. If you aren't a member of the inner circle, you don't really get to know, nor do you want to, because each and every compound used in medicine has it's own International Unit and it's own circle of experts. Since there are zillions of compounds in use you could spend your entire life learning just what an International Unit is for each of those compounds.

In pharmacology, the international unit is a unit of measurement for the amount of a substance; the mass or volume that constitutes one international unit varies based on which substance is being measured, and the variance is based on the biological activity or effect, for the purpose of easier comparison across substances.

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Since the number of IUs contained in a new substance is arbitrarily set, there is no equivalence between IU measurements of different biological agents. For instance, one IU of vitamin E cannot be equated with one IU of vitamin A in any way, including mass or efficacy. - Wikipedia