Premenstrual syndrome, or PMS, is a natural, biological process that women experience. It occurs for up to two weeks prior to menstruation and has been associated with a deficiency or excess of hormones. Symptoms of PMS include increased levels of anger and stress, bloating, breast tenderness, abdominal discomfort, sadness, short-term fatigue, head discomfort, hostility, trouble sleeping, joint discomfort, mood swings, nervousness and tension. PMS has been associated with a deficiency or excess of hormones, stress, weight gain, nutritional deficiencies and other nutritional or lifestyle factors.

Menopause is the ceasing of the monthly female menstrual cycle. A woman is considered menopausal when she has been without a menstrual cycle for at least one year. Symptoms of menopause are caused by the loss of estrogen. However, not all menopause symptoms can be treated by estrogen. Common symptoms of menopause are emotional and physical changes, mood swings, sleeplessness, increased irritability, low energy and mood, painful intercourse due to vaginal dryness, hot flashes and night sweats. Some women experience perimenopause prior to menopause, which is a time period that can include many of the symptoms of menopause before menstruation stops.

Estrogens are a group of steroid compounds that are named for their importance in the estrus cycle. They function as the primary female sex hormone. Estrogen is present in men and women but is usually at significantly higher levels in women of reproductive age. Estrogen is mainly produced in the developing follicles in the ovaries, but some is also produced by secondary sources such as the liver, adrenal glands and breasts. The secondary sources are particularly important for post-menopausal women. Estrogens function structurally to promote the formation of female secondary sex characteristics, stimulate endometrial growth, increase uterine growth and increase vessel and skin maintenance and bone formation.