Diagnos-Techs™ Laboratory has developed a very accurate way to assess levels of these hormones. Multiple saliva samples collected over the course of a month are used to measure the cyclical fluctuations of estrogen and progesterone. Saliva is actually superior to blood for evaluating these hormones because it accurately reflects the concentrations of "free" hormones in circulation. Hormones in the bloodstream are mostly protein-bound which makes them inactive. It is only the free or unbound hormone that is able to pass into the cells and exert activity. For premenopausal women and for those women less than five years past menopause, this test gives extremely valuable information regarding not only the absolute levels, but also the cyclical relationships of these hormones – something that is unique to each woman. Testosterone and DHEA levels are also measured with this test. This information allows for greater customization of hormone replacement with regard to which hormones to supplement, the quantities to use, and the days during the month that they should be taken. By comparison, a single blood sample gives very limited insight into the cycling of these hormones. Repeat testing, after using the hormones for several months, allows for fine-tuning of therapy. In women more than five years past menopause, the hormones are no longer secreted in a cyclical fashion. In this situation and for men as well, a single saliva specimen is all that is required to measure levels of these hormones.