What Happens to Hormones During Menstruation?

Typically, women experience significant changes in levels of hormones during menstruation. At this time, women usually experience a drop in their levels of estrogen, which is the primary sex hormone for females, and progesterone, a hormone that is important in both menstruation and pregnancy. During menstruation, gonadotropin-releasing hormone is produced, which stimulates the release of follicle stimulating hormone. This hormone's release acts on a woman’s ovaries to begin the process of producing an egg that may be fertilized after ovulation.

The hormones estrogen and progesterone are present at varying levels during a woman’s menstrual cycle. They are usually at the lowest levels when a woman is menstruating, however. This is due to the fact that estrogen and progesterone play critical roles in the development of the uterine lining that is shed during menstruation. The drop in levels of these hormones helps facilitate the onset of menstruation.

Another hormone that is active during menstruation is the gonadotropin-releasing hormone. This hormone is produced as a result of stimulation of the hypothalamus gland, which is located in the part of a person’s brain that controls not only her behavior, but also her emotions. This gland also produces and releases various hormones that affect the pituitary gland, which is located at the bottom of the human brain. In particular, the hypothalamus gland secretes gonadotropin-releasing hormone during a menstrual period, which causes the pituitary gland to secrete hormones during menstruation.

The pituitary gland releases follicle stimulating hormones during menstruation. This hormone begins the phase in which a woman’s egg follicles mature. Eventually, this hormone also stimulates the rise in estrogen levels that leads to a surge of luteinizing hormone later in a woman’s cycle. This surge of luteinizing hormone usually occurs several days after menstruation has ended and stimulates the bursting of an egg from a follicle. This event is referred to as ovulation.

Often, the changes in hormones during menstruation mark a period of emotional change as well. As estrogen and progesterone levels fall leading up to menstruation, many women experience premenstrual syndrome, which is marked by mood swings, fatigue, changes in appetite and libido, and bloating. Once a menstrual period begins, however, many women feel better than they did during the premenstrual phase. Often, women feel more at peace during this phase and have fewer emotional fluctuations. This feeling of calm may result from the normalization of levels of estrogen and progesterone.