One of estrogen's main functions is to control sexual development, a process in which estrogen plays a central role. A few years before menarche (the time at which a girl experiences her first menstrual period) estrogen levels begin to rise. Around the age of twelve or thirteen they are high enough to bring about ovulation. Somewhat earlier than this, a girl begins developing breasts, and secondary sex characteristics such as underarm and pubic hair. Estrogen levels then fluctuate monthly in producing the menstrual cycle and then, some years before menopause, estrogen levels begin to fall.

Not infrequently, during the years of fertility, the menstrual cycle may bring its own problems, especially as a woman reaches her thirties and beyond. Symptoms such as severe cramps, are not uncommon, as well as intense mood swings, the latter often coming under the general heading of PMS (premenstrual syndrome). We have seen that adjusting the levels of estrogen and progesterone - in proper balance - has been effective in curtailing these symptoms.

Not infrequently, PMS may in fact be due to an excess of estrogens and to a deficiency of progesterone. Estrogen dominance or estrogen excess may be associated with:

1. Body fat increase.
2. Breast pain and swelling.
3. Blood sugar abnormalities.
4. Water retention and bloating.
5. Cancer of the uterus and breast.
6. Thyroid dysfunction.
7. Headaches and worsened migraines.
8. Infertility, miscarriages, and menstrual irregularities.
9. Phlebitis and blood clotting problems.
10. Depression, irritability, and fatigue.
11. Memory loss and unclear thinking.
12. Decreased sex drive.