​​​​​​​​​​​Welcome to the Women's Health Initiative

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.