The Women’s Health Initiative (WHI) was established by the U.S. National Institutes of Health in 1991 to study the health of postmenopausal women. Among the many issues this cohort study investigated were the link between hormone therapy and breast cancer, and the effects of diet on cancer and heart disease. The talc-use portion of the WHI included 61,576 women, 53 percent of whom said they have used powder on their genitals, sanitary napkins or diaphragms, some for over 20 years. The women in this study were followed between 1993 and 2012.
The study data showed no increased risk of ovarian cancer in women who used talcum powder. There was also no increase in risk among women who used powder for longer periods of time.6