NCT03043924

Who might be able to join this trial:

• You are between 19 and 30 years old
• Your body mass index (a measure of body weight relative to height) is between 18 and 25
• You are willing and able to give your written agreement to take part before the study begins
• You have not smoked in the 3 days before your MRI scan

If you are a healthy volunteer, you also need to meet these conditions:

• Your menstrual cycles are regular (between 25 and 35 days) and you ovulate normally
• You have no signs of excess male hormones (such as excess hair growth or acne) (confirm with trial site)
• You are willing to start taking a combined oral contraceptive pill (containing both oestrogen and progestin)
• For your second MRI scan: you will need to have been taking a specific low-dose combined contraceptive pill correctly for 3 months (confirm with trial site for exact pill details)

If you have Polycystic Ovary Syndrome (PCOS), you also need to meet these conditions:

• You have been diagnosed with PCOS using a standard set of medical criteria called the Rotterdam criteria (confirm with trial site)
• You need treatment with a medication called cyproterone acetate
• For your second MRI scan: you will need to have been taking cyproterone acetate combined with a specific form of oestrogen correctly for 3 months (confirm with trial site for exact medication details)

Who may not be able to join:

• You have taken any hormone treatment, including the contraceptive pill, in the last 3 months
• You are currently pregnant (this will be checked before each MRI scan)
• You experience claustrophobia (fear of enclosed spaces, such as an MRI scanner)
• You have any metal objects or implants inside your body, such as aneurysm clips, ear implants, a pacemaker, or a defibrillator
• You have diabetes or a known thyroid condition
• You currently misuse substances, including smoking more than 5 cigarettes per day (this will be checked at your first visit)
• You have been pregnant or breastfeeding in the last 3 months
• You did intense exercise (for example, running more than 10 km) the day before your MRI scan
• You are not able to give your own informed consent, or you are under a form of legal guardianship
• You are unable to understand the treatment plan for this trial

Important: Always verify eligibility with the trial site directly before applying.