Therapeutic response to metformin in an underweight patient with polycystic ovarian syndrome.

To report a case where insulin sensitization restored menses in an underweight woman with polycystic ovarian syndrome (PCOS).Case report.Tertiary care center.A 19-year-old woman with a body mass index of 16.9 kg/m(2), severe hirsutism, and oligomenorrhea.Insulin sensitization with metformin.Impact of metformin therapy on menstrual cycle and serum T and fasting insulin levels.Metformin, without weight loss or increased physical activity, resulted in restoration of menstrual cycle, reduction in serum T, and improvement in insulin resistance (IR).This case highlights the contribution of PCOS-related IR, distinct from visceral adiposity, and demonstrates the effectiveness of pharmacological insulin-sensitization independent of weight loss or lifestyle adjustments.