Women's Health Initiative Study on Menopause and Hormone Replacement

The Women's Health Initiative (WHI) study on menopause and hormone replacement therapy (HRT) was a groundbreaking research project that investigated the effects of HRT on postmenopausal women. The study, which began in 1991 and concluded in 2002, was conducted by the National Institutes of Health (NIH) and involved over 161,000 women. The findings of the study had a significant impact on the way menopause and HRT are treated and understood today. The study's results, which were published in the Journal of the American Medical Association (JAMA), showed that HRT increased the risk of breast cancer, heart attacks, and strokes, leading to a major shift in the way HRT is prescribed and used.