This study will be performed as a multi-center, randomized, double-blind study in 60 healthy women (2 groups of 30 women) to investigate ovarian activity during simultaneous intake of a COC (containing the estrogen EE and the progestin LNG) and the progesterone receptor modulator (PRM) vilaprisan.

Inclusion Criteria:

• Healthy female premenopausal subjects
• Age: 18 to 35 years (inclusive)
• Body mass index (BMI) : ≥18 and ≤30 kg/m²
• Non-smoker for 3 months (former smokers who quit smoking >3 months before the first study drug administration may be included)

Exclusion Criteria:

• Incomplete recovery from pre-existing disease for which it can be assumed that the absorption, distribution, excretion, and effect of the study drugs will not be normal
• presence or history of thrombophlebitis, venous or arterial thrombotic/thromboembolic events (e.g. deep venous thrombosis, pulmonary embolism, myocardial infarction) or of a cerebrovascular accident