In a move that has angered researchers in the federal Women's Health Initiative (WHI), the company, Wyeth Pharmaceuticals, used the Freedom of Information Act to request the WHI data from the National Institutes of Health (NIH).

NIH officials, advised by their lawyers that the company would likely win a legal battle over the FOIA request, agreed instead to provide the data voluntarily. In return, Wyeth withdrew the FOIA request and signed an agreement not to publish articles on the data until WHI researchers have finished publishing the study's findings.

Wyeth makes Prempro and Premarin, the drugs tested in the WHI, and donated the drugs used in the study. Sales of those hormone products and others have fallen sharply since last July, when WHI researchers halted part of the study early and announced that for healthy post-menopausal women, they had concluded that combination therapy with the hormones estrogen and progestin did more harm than good. An estimated 14 million post-menopausal women in the United States were on some form of hormone therapy, including an estimated 6 million on the combination.