Used in combination oral contraceptives to prevent ovulation by regulating hormonal levels. Commonly found in birth control pills, it works with progestins to inhibit follicle development and alter cervical mucus to prevent sperm penetration. Also used in hormone replacement therapy for menopausal symptoms and in treatment of certain hormonal disorders. Due to its estrogenic activity, it helps manage hypoestrogenism in conditions like Turner syndrome or ovarian failure.