• Age range within the AYAs category (\> 12.0 years and ≤ 23.9 years at study start) (96); Given that another inclusion criterium is gynaecological age (years elapsed since menarche) of 2 years or more, and that menarche before age 10.0 years is an exclusion criterium (please see exclusion criteria below), the youngest participant will be older than 12.0 years at study start (97). The upper age limit at study start is set at 23.9 years (thus, 24.9 years when the active treatment ends, see section 7. Conduct), in order to avoid early dropouts due to an increase in the prevalence of pregnancy wish beyond that age in most European countries;

• Gynaecological age of 2 years or more;

• Clinical androgen excess, as defined by the presence of hirsutism (modified Ferriman-Gallwey score ≥ 4) (17,98) and/or inflammatory acne (Leeds scale) unresponsive to medications (3,95,99). The scarce normative data existing in adolescents suggest that an adult level of hirsutism is reached around 2 years after menarche (100);

• Biochemical androgen excess, as defined by increased total testosterone (≥50 ng/dL), and/or a FAI higher than 3.5 \[FAI, total testosterone (nmol/L) x 100/SHBG (nmol/L)\], in the follicular phase of the cycle (days 3-7) or after 2 months of amenorrhea (3,100,101); Measurements of total testosterone and/or FAI are the most recommended assessments to screen for hyperandrogenaemia (3,19,95,102). Serum testosterone attains adult levels shortly after menarche; thus, an elevation of serum testosterone concentrations and/or FAI above adult norms and assessed in reliable reference laboratories constitutes biochemical evidence of hyperandrogenism (3,19,95,100). It is accepted that this upper limit can be set at 45 ng/dL for testosterone and at 3.5 for FAI (3,95,100,101,102,103). Direct free testosterone assays, such as radiometric or enzyme-linked assays, preferably should not be used in the assessment of biochemical hyperandrogenism, as they demonstrate poor sensitivity, accuracy and precision (17);

• Menstrual irregularity, as defined by ≤ 8 menses per year corresponding to an average inter-menstrual time of ≥45 days (3,95,100); Most adolescents establish a menstrual interval of 20-45 days within the first 2 years after menarche (3,95). Three years after menarche, the 95th percentile for cycle length is 43.6 days (104); thus, cycles longer than 45 days (\<8 periods/year) at or beyond this gynaecological age are considered abnormal and are evidence of oligo-anovulation;

• Written informed consent obtained from the patient, or assent from the patient and consent by the parents or the legally acceptable representative if she is a minor (for details, see section 7. Conduct, under informed consent).