Estrone is primarily used in hormone replacement therapy (HRT) to alleviate symptoms of menopause, such as hot flashes, night sweats, and vaginal dryness. It helps restore estrogen levels in postmenopausal women, improving overall quality of life. Additionally, estrone is utilized in the treatment of certain hormonal imbalances and conditions like osteoporosis, where it aids in maintaining bone density. In research, it serves as a reference compound for studying estrogen metabolism and its effects on various biological processes. It is also used in the development of diagnostic tools for assessing estrogen-related health issues.