They control heavy bleeding by reducing (thinning) the thickness of the inner lining of the uterus. They can be helpful even if you do not desire birth control. The following groups of women should NOT use these hormonal treatments:
1. Women with a history of blood clots in their legs
2. Women with a history of blood clots in their lungs
3. Women with a history of breast cancer
4. Women over 35 years of age who are smokers