Known, past or suspected breast cancer; Known or suspected estrogen-dependent malignant tumours (e.g. endometrial cancer); Undiagnosed genital bleeding; Untreated endometrial hyperplasia; Previous or current venous thromboembolism (deep venous thrombosis, pulmonary embolism); Known thrombophilic disorders (e.g. protein C, protein S, or antithrombin deficiency, see Precautions); Active or recent arterial thromboembolic disease (e.g. angina, myocardial infarction); Acute liver disease, or a history of liver disease as long as liver function tests have failed to return to normal; Porphyria; Hypersensitivity to the active substance or to any of the excipients listed in Description.