Used historically as a synthetic estrogen in medical treatments, particularly for menopausal symptoms and to prevent miscarriages in pregnant women. It was also administered to livestock to promote growth, enhancing feed efficiency and weight gain in cattle. Later linked to serious health risks, including increased risk of vaginal cancer in daughters exposed in utero, leading to restrictions in human use. Still referenced in research on endocrine disruptors and long-term effects of prenatal hormone exposure.