Norethisterone is a man-made form of progesterone, a naturally recurring female sex hormone and is used for a number of reasons. It cannot be used as hormone replacement therapy (HRT). Medium-strength tablets can treat heavy periods and are even used for some female cancers, such as breast cancer.
How It Works:
Normally, the level of progesterone in your body drops before your period. When it falls below a certain level, the lining of the womb is shed as a menstrual period. By taking Norethisterone which is a period delay tablet, the lining of the womb is sustained until the tablet is stopped hence preventing the you from having your regular period.