The first-ever long-term study of hormone replacement therapy was the widely-known as the Women’s Health Initiative (WHI). This study began in 1991 and was expected to run for 15 years, observing the effects of hormone therapy, using synthetic/traditional hormones, on postmenopausal women. The focus of the study was to define the risks and benefits of using synthetic hormone therapy to potentially prevent heart disease, breast cancer, colorectal cancer and osteoporosis in postmenopausal women.
One branch of the study was abruptly halted in 2002, when researchers began to observe significantly adverse health effects in women on combined estrogen-progestin therapies.
The subjects of the study were limited to postmenopausal women, with a combined average age of sixty-eight. These two factors are significant - most of the women studied had been in a state of hormonal decline or complete loss of hormones for 15 years or more, putting them at-risk for the development of diseases that estrogen, progesterone and testosterone might have prevented if administered earlier in the lifespan.
The 10-year anniversary of the halting of this study was marked on July 9, 2012. Over the course of the last 10 years multiple studies and analyses have been conducted refuting the findings that suggested hormone therapy caused death and disease. Today, 15 of the top medical organizations in the country support hormone therapy as a safe and effective treatment for menopause and related disorders of hormone imbalance.