First-line medical treatments for PCOS, following the American Society for Reproductive Medicine guidance, with a note that classifications vary between guidelines. The chapter explains the combined oral contraceptive pill, usually the first choice for irregular periods and for symptoms of excess androgens such as acne and unwanted hair growth. It covers metformin, a diabetes medicine that improves how the body responds to insulin, and eflornithine cream, which slows facial hair growth but does not remove existing hair. For women trying to conceive, it describes clomiphene, which stimulates ovulation and is a first-line fertility treatment.