Progesterone

Progesterone is a hormone produced in the ovaries during the second half of the menstrual cycle that helps prepare the uterus for pregnancy. Progesterone is also produced by the placenta during pregnancy and helps the placenta function properly.

At the end of pregnancy, a drop in progesterone helps start labor contractions.

When a woman reaches the end of her reproductive years and begins menopause, her level of progesterone declines.