Estrogen-progestin pills double postmenopausal women’s chances of developing dangerous blood clots, and the risk is even higher for overweight patients and those over 60, researchers say. The findings continue the drumbeat of bad news about estrogen that has led to a sharp drop in sales of the supplements, which have long been prescribed to relieve such symptoms of menopause as hot flashes and vaginal dryness. The results came from the Women’s Health Initiative, the same government study that was halted two years ago after Prempro estrogen-progestin pills appeared to raise the risk of heart attacks, strokes and breast cancer. Later WHI data found that Premarin, an estrogen-only pill, was risky, too.