This clinical research study will examine whether an oral contraceptive pill taken with a monthly hormone-free interval of 4 days reduces hormone withdrawal associated symptoms compared to an oral contraceptive pill taken with a monthly hormone-free interval of 7 days after 4 cycles of treatment.

Inclusion Criteria:

• Subjects aged between 18 and 35 years (inclusive)
• Smokers with a maximum age of 30 years at time of informed consent
• Healthy female subjects requesting contraception and currently using a low-dose EE containing oral contraceptives (OC) in a 21-day regimen (for at least three months) and suffering from at least two of the hormone withdrawal associated symptoms headache, pelvic pain and bloating during all three months prior the planned baseline cycle and requiring further OC use
• To be valid for randomization, the total 7-day composite score of hormone-withdrawal symptoms during the baseline cycle must show an increase of at least 50% during Day 22 - 28 versus the 21-day composite score during Day 1 - 21 (21-day score divided by three [for normalization])
• History of regular cyclic menstrual periods

Exclusion Criteria:

• Presence or a history of venous or arterial thrombotic/thromboembolic events (e.g. deep venous thrombosis, pulmonary embolism, myocardial infarction) or of a cerebrovascular accident, or presence or history of prodrome of a thrombosis (e.g. transient ischemic attack, angina pectoris) and conditions that could increase the risk to suffer from any of the above mentioned disorders, e.g., a family history indicating a hereditary predisposition. Hereditary or acquired predisposition for venous or arterial thrombosis, such as APCresistance, antithrombin-III-deficiency, protein C deficiency, protein S deficiency, hyperhomocysteinemia and antiphospholipid-antibodies (anticardiolipin-antibodies, lupus anticoagulant).
• History of migraine with focal neurological symptoms.
• Diabetes mellitus with vascular involvement.
• Obesity (Body Mass Index >32.0 kg/m2)
• Moderate to severe hypertension (repeated measurements of systolic blood pressure >140 mmHg and/or diastolic blood pressure >90 mmHg).
• Pancreatitis or a history thereof if associated with severe hypertriglyceridemia.
• Presence or history of severe hepatic disease as long as liver function values have not returned to normal.
• Jaundice and / or pruritus related to cholestasis (Gilbert´s syndrome excepted), or history of cholestatic jaundice associated with pregnancy or previous combined OC use
• Severe renal insufficiency or acute renal failure.
• Presence or history of liver tumors (benign or malignant), or known or suspected sex-steroid influenced malignancies or premalignant disease (e.g. of the genital organs or the breasts).