The Women’s Health Initiative, the largest and longest-running study of women’s health in United States history, faces unprecedented funding cuts from the Department of Health and Human Services (HHS) that will force the closure of regional research centers by September 2025. This decision threatens to end a groundbreaking study that has transformed clinical care for postmenopausal women over more than three decades.
The funding cuts come as part of the Trump Administration’s mandate to reduce $2.6 billion in National Institutes of Health (NIH) contracts. WHI investigators were informed of the decision earlier this week, though formal written notice from HHS remains pending. The initiative has been predominantly funded by the NIH National Heart, Lung, and Blood Institute since its launch in 1991.
Impact on Decades of Research
The Women’s Health Initiative has enrolled more than 161,000 women aged 50 to 79 years across 40 clinical centers nationwide. Today, more than 42,000 participants, now aged 78 to 108 years, remain actively engaged in the study. The research has documented 38,000 cases of cancer, 38,000 cardiovascular events, 70,000 bone fractures, and 95,000 deaths, creating an invaluable dataset for understanding women’s health and aging.
One of the initiative’s most notable achievements was the estrogen plus progestin hormone therapy trial, which transformed prescribing patterns worldwide. This research led to the prevention of an estimated 126,000 breast cancer cases and 76,000 cardiovascular disease cases over a decade, saving more than $35 billion in direct medical costs.
Scientific Community Responds
The WHI Clinical Coordinating Center (CCC) will remain operational until January 2026, after which its funding status remains uncertain. If funding for the CCC is also discontinued, access to the comprehensive data repository and biorepository could be severely curtailed, limiting potential for future discoveries and stalling progress in women’s health research.
The multidisciplinary structure has facilitated over 2,400 peer-reviewed publications and the development of 342 ancillary studies, with 30 currently active. The initiative has engaged over 5,000 investigators and fostered collaborations with major consortia, including TOPMed, PAGE, and the National Cancer Institute’s Cancer Cohort Consortium.
As news of the funding cuts spreads through the public health community, experts warn of far-reaching consequences for scientific understanding of aging and chronic disease among women. The termination threatens ongoing research into preventing heart disease, breast and colorectal cancers, and osteoporosis strategies that have been decades in development.