Effect of Metformin on Adrenal or Ovarian Androgen Production in Overweight Pubertal Girls With Androgen Excess

Inclusion Criteria: * Overweight(\>85th BMI%) females * Early to late puberty (expected age range 7-18) * Hyperandrogenemic (free testosterone greater than 2.5 standard deviations above the mean for normal control subjects of the same Tanner Stage) * Screening labs within age-appropriate normal range, with the exception of a mildly low hematocrit (see below) and the hormonal abnormalities inherent in obesity which could include mildly elevated luteinizing hormone (LH), lipids, testosterone, prolactin, DHEAS, E2, glucose, and insulin; and decreased follicle-stimulating hormone (FSH) and/or sex hormone-binding globulin (SHBG) Exclusion Criteria: * Age \< 7 or \> 18 y * Inability to comprehend what will be done during the study or why it will be done * BMI-for-age \< 5th percentile * Positive pregnancy test or lactation. * Abnormal laboratory studies will be confirmed by repeat testing to exclude laboratory error. * Morning cortisol \< 3 µg/dL or history of Cushing syndrome or adrenal insufficiency * History of congenital adrenal hyperplasia or 17-hydroxyprogesterone \> 300 ng/dL, which suggests the possibility of congenital adrenal hyperplasia (if postmenarcheal, the 17-hydroxyprogesterone will be collected during the follicular phase, or ≥ 40 days since last menses if oligomenorrheic). NOTE: If a 17-hydroxyprogesterone \>300 mg/dL is confirmed on repeat testing, an ACTH-stimulated 17-hydroxyprogesterone \<1000 ng/dL will be required for study participation. * Total testoste…