A major study suggests that lower doses of the hormones estrogen and progestin as a therapy for menopausal women work just as well as higher doses, with fewer side effects. As many women fear, and doctors debate, that hormone replacement therapy may cause breast cancer, a low-dose hormone replacement regimen could become in demand in the near future. Hormone replacement therapy is used to control the symptoms of menopause, including hot flashes, or to cut the risk of osteoporosis. Side effects of this therapy can include irregular bleeding and breast tenderness; lower doses of estrogen and progestin can alleviate those side effects, two recent reports released in Fertility and Sterility assert. One study states that lower doses were as effective as higher doses in reducing hot flashes and preventing the thinning of vaginal lining, which causes infections and painful intercourse. The second report shows that the same low-dose combinations worked about as well as higher doses in preventing irregular bleeding.