Norethisterone is a synthetic hormone that can be used for birth control, menstrual cycle regulation, and hormone replacement therapy. It's a progestin, which means it's a synthetic version of the hormone progesterone, which the body naturally produces.

Norethisterone is available in a variety of forms, including tablets, injections, and implants. It prevents ovulation and thickens the cervical mucus, making it more difficult for sperm to reach the egg when used for birth control. It can help to balance hormone levels and alleviate symptoms such as irregular periods, heavy bleeding, or hot flashes when used to regulate the menstrual cycle or as hormone replacement therapy. Norethisterone, like all medications, can cause side effects such as headaches, nausea, breast tenderness, and mood changes. Before taking norethisterone, consult with your doctor to ensure that it is safe and appropriate for your specific needs.