Women depend on their reproductive hormones in many ways. During the reproductive years, estradiol, the most powerful of the estrogen family, is produced largely by the ovaries. While it is important for menstrual cycles and pregnancy, we now know that estradiol plays a key role in keeping your body in an uninflamed state. Estradiol accomplishes this by depressing the ability of your fat cells and immune cells to produce a number of inflammatory proteins that are linked to many of the menopausal symptoms women describe. Even in the several years leading up to that one year without a menstrual period (a window of time called the Menopause Transition), fluctuations in ovarian production of estradiol cause the release of these inflammatory proteins. These fluctuations explain why mood swings, hot flashes, skin changes, and loss of libido may be encountered, even as the menstrual periods still are occurring.