At menopause the ovaries stop producing estrogen. However, the other sources continue to produce estrogen. The important point to remember is that due to these other sources, the body does not just stop producing estrogen at menopause. Yet they can be more at risk for diseases that have been linked to estrogen output, such as endometrial and breast cancer. Therefore more estrogen remains more active or potent within their systems.
Women have dozens of types of circulating estrogens.
Three of them are important. Estradiol Estradiol is produced by the ovaries. It is the primary circulating estrogen before menopause. It is also the strongest estrogen and is responsible to the monthly ovulation and normal menstrual cycles. Estrone Estrone is produced by the fatty tissues.