Inclusion Criteria:

- Healthy female subjects

- Sterilized by tubal ligation

- Age 18-45 years

- Body mass index (BMI) at screening: ≥ 18 and ≤ 32 kg/m²

- At least 3 consecutive regular menstrual cycles with a cycle length of 24 - 35 days
before first screening examination according to the subject's history

- Absence of clinically relevant abnormal findings in the pre-treatment endometrial
biopsy

Exclusion Criteria:

- Regular use of medicines (incl. anabolics)

- Incompletely cured pre-existing diseases for which it can be assumed that the
absorption, distribution, metabolism, elimination and effects of the study drugs will
not be normal

- Amenorrhea for more than 3 months within the last 6 months before the first screening
examination

- Lacking suitability for frequent transvaginal ultrasonography (TVU) examinations

- Clinically relevant findings (e.g. blood pressure, electrocardiogram [ECG], physical
and gynecological examination, laboratory examination)