Slideshows Images Quizzes

Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. See additional information.

Definition of Precursor

  • Medical Author:
    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Precursor: Forerunner. That which precedes or is derived from an available source.

The term "precursor" is applied to an inactive substance converted to an active one (such as an enzyme, vitamin, or hormone). The term "precursor" applies to any chemical that is transformed into another.

From the Latin "praecursor," composed of "prae-" (or pre-), before + "curro" to run = to run before.

Reviewed on 12/11/2018

Health Solutions From Our Sponsors