The Women's Health Initiative (WHI) is a long-term national health study focused on strategies for preventing heart disease, breast and colorectal cancer, and osteoporotic fractures in postmenopausal women. Launched in 1993, the WHI enrolled 161,808 women aged 50-79 into one or more randomized Clinical Trials (CT), testing the health effects of hormone therapy (HT), dietary modification (DM), and/or
calcium and Vitamin D supplementation (CaD) or to an
Observational Study (OS). At the end of the initial study period in 2005, WHI Extension Studies (2005-2010,
2010-2020) continued follow-up of all women who consented.
This ground-breaking study changed the way health care providers prevent and treat some of the major diseases impacting postmenopausal women. Results from the WHI Hormone Trials have been estimated to have already saved $35.2 billion in direct medical costs in the US alone. To date, WHI has published over 1,400
articles and approved and funded 289 ancillary studies.
Interested scientists are encouraged to submit paper and ancillary study proposals for using WHI data. To assist in this, this website includes an
overview of WHI,
study documentation, and information on how to
submit a paper or
ancillary study proposal.
Problems with Sign-In
Need Help? Contact the Study!
View past news stories