Progesterone receptor modulators

Progesterone receptor modulators are agents that act on the progesterone receptors. They act as agonists or antagonists. Some progesterone modulators act as agonists in some tissues and antagonists in other tissues.

Progesterone receptor modulators that have both agonist and antagonist activity can be used for emergency contraception.

Agents that act as progesterone antagonists are used as abortifacients. They block the effects of progesterone, which is essential during pregnancy, therefore leads to termination of the pregnancy.