Changes in progesterone levels

The hormone progesterone acts in both the female and male bodies.

In women, progesterone levels increase towards the second half of the menstrual cycle, i.e., once ovulation has taken place. If pregnancy does not occur, progesterone levels drop towards the end of the menstrual cycle. However, if the egg is fertilized, i.e., pregnancy occurs, progesterone levels in women will remain stable.