Raloxifene is a selective estrogen receptor modulator (SERM) used primarily to prevent and treat postmenopausal osteoporosis by increasing bone mineral density and reducing fracture risk. It also lowers the risk of invasive breast cancer in postmenopausal women with osteoporosis or those at high risk, such as having first-degree relatives with breast cancer or certain biopsy findings. Acting like estrogen on bones but blocking it in breast tissue, raloxifene helps maintain bone strength without stimulating the uterus. It's available as a daily oral tablet, often paired with calcium and vitamin D for optimal effect.