The popular herbal treatment black cohosh is practically ineffective at relieving hot flushes and night sweats in menopausal women, according to research in the US. In results published in the Annals of Internal Medicine, Group Health [a health plan provider] says in a year-long survey women on a placebo experienced the same relief from flushes and sweats as did those on the supplement ? which was much less than that felt by women given hormone treatment. The study was funded by the US National Institute on Aging and the National Center for Complementary and Alternative Medicine.