Background: PCOS is a common condition with a prevalence of 5-8 % in premenopausal women. More than 50% of PCOS patients are insulin resistant and have a diabetes risk 5-8 times higher than age- and weight-matched controls. Studies using insulin sensitizers in PCOS found increased insulin sensitivity and decreased insulin levels to be followed by decreased androgen levels and improved ovulatory function. No studies however, evaluated the long term effects of insulin sensitizing treatment.

Oral contraceptives normalize menstrual cycles and suppress androgen levels in PCOS, however no long-term studies evaluated the effects of combined treatment with metformin and oral contraceptives in PCOS.

Design: Randomized open study in 3*30 PCOS patients. Patients are randomised to 24 months of treatment with 1: metformin, 2: metformin and oral contraceptives or 3: oral contraceptives.

Primary outcome measures: fasting insulin, AUC insulin. Secundary endpoints: BMI, WHR, LH, FSH, total and free-testosterone, c-peptid, urinary cortisol, AUC for insulin, glucose and c-peptid during OGTT.

Inclusioncriteria:

1. Irregular menses or anovulaty cycles
2. High free testosterone > 0,035 nmol/l or hirsutism
3. PCO in vaginal US Criteria 1 and 2 OR 2 and 3.

Design: