Answer:
Hormonal Control Of Menstrual Cycle
The ovarian hormones circulate in the blood and are excreted in modified forms in the urine. Estimation of the urinary output by chemical methods gives an indication of the blood levels and of the total production of these substances. There are several natural estrogens, and numerous synthetic modifications of these and of progesterone have been devised; many are active when taken by mouth and are used for treatment of hormonal disorders and as oral contraceptives.
