We examine how new medical information on drug safety impacts preventive health care use. We exploit the release of the findings of the Women's Health Initiative Study (WHIS)-the largest randomized controlled trial of women's health-which demonstrated in 2002 the health risks associated with the long-term use of hormone replacement therapy (HRT). We first show that, after the release of the WHIS findings, HRT use dropped sharply among post-menopausal women. We then estimate the spillover effects of the WHIS findings on preventive care by means of a difference-in-differences methodology comparing changes in preventive care use among 60 to 69 year-old women (who have high rates of HRT use) with the change among women aged 75 and above (who have much lower rates of HRT use). Using data from the Behavioral Risk Factor Surveillance System for the period 1998-2007, we find that women aged 60-69 had statistically and economically significant declines in their annual mammography checks, checkups, cholesterol checks and blood stool tests, when compared to older women.