University of Illinois Chicago Mar 30 2026 Polycystic ovary syndrome, or PCOS, affects as many as 18% of all childbearing-age women. The condition occurs when a woman's body produces too much of a group of hormones called androgens, chiefly testosterone. Menstrual irregularity, obesity and even infertility can result. The first line of treatment is typically hormonal birth control, said UIC professor of nutrition Krista Varady. But there can be negative side effects to mood, libido and