The hormones being tested are estrogen alone as well as estrogen combined with progestin, and the trial is scheduled to run for an average of nine years. The WHI will examine the long term effects of HRT on heart attacks, strokes, blood clots, fractures, and cancers. Recruitment for the study will be completed this month, according to schedule, and results will be available after 2005. They will help to prove whether the theory is correct that HRT produces a long term positive effect on the progression of atherosclerosis. This is a multicenter trial involving 400 to 450 women.
Participants also receive the cholesterol-lowering drug lovastatin.
When completed, these studies, together with the results of HERS, should provide the first comprehensive evaluation of the benefits and risks of long-term hormone replacement therapy.