What Hormones Cause PMS?
PMS most often occurs in women with normal menstrual cycles. During the normal menstrual cycle, the ovaries make two main hormones, calledestrogen and progesterone. Estrogen is made by the ovaries throughout the entire menstrual cycle. It reaches its highest levels during the second and third weeks and declines during the last week. During the last two weeks of the cycle the ovaries also make progesterone. The last two weeks of the menstrual cycle is called the luteal (secretory) phase. Both estrogen and progesterone prepare the uterus (womb) to accept a fertilized egg. Both estrogen and progesterone also affect women’s moods.
