Tranexamic acid is an antifibrinolytic that is used in conditions where excessive bleeding is not desirable, e.g. menorrhagia and trauma.

Mechanism of action

Tranexamic acid is a synthetic derivative of lysine. Its primary mode of action is as an antifibrinolytic that reversibly binds to lysine receptor sites on plasminogen or plasmin. This prevents plasmin from binding to and degrading fibrin.


Tranexamic acid is most commonly prescribed to help treat menorrhagia.

The role of tranexamic acid in trauma was investigated in the CRASH 2 trial and has been shown to be of benefit in bleeding trauma when administered in the first 3 hours.

There is also ongoing research looking at the role of tranexamic acid in traumatic brain injury.