Inclusion Criteria:  Healthy women at 18-22 years of age No use of hormonal contraception within the last year Having a regular menstrual cycle of approximately 28 days, i.e., approximately 28 days between first day of menstrual bleedings.  Exclusion Criteria:  Current or previous neurological or psychiatric disease, severe somatic disease, or consumption of medical drugs likely to influence the test results Non-fluent in Danish or pronounced visual or auditory impairments Current or past learning disability Current or previous pregnancy A wish to become pregnant within the following 6 months Participation in experiments with exposure to radioactivity (> 10 mSv) within the last year or significant occupational exposure to radioactivity Contraindications for MRI (pacemaker, metal implants, claustrophobia) Allergy to the ingredients in the administered drug A diagnosis of hypo- or hypertension A history of head injury or concussion resulting in loss of consciousness for more than 2 min Alcohol abuse Drug use other than tobacco and alcohol within the last 30 days Cannabis > 50 x lifetime Recreational drugs > 10 x lifetime (for each substance) Nicotine addiction Current psychoactive medication Any risk factors for thromboembolic events Other contraindications for use of Femicept