But a second study by the same researchers found that women taking Prempro, the hormone-replacement medication used in the clinical comparison, fared worse on a key cognitive complaint about menopause: memory. The studies are published in the August issue of the journal Menopause. University of Illinois, Chicago psychiatry professor Pauline Maki called the additional memory decline that came with Prempro use 'slight.' But, she added, the effect leaves researchers hunting for medication that can ease hot flashes and night sweats without worsening memory problems for women making the menopausal transition. Among the 89 women with moderate to severe hot flashes related to menopause, those who were given the second-place finisher -- a dummy pill -- had a powerful response, the study found. Over the 12-month study period, during which the women recorded the frequency and intensity of their surges, those on the dummy pill observed a 63 percent reduction in hot flashes. That made placebo more effective than red clover, which reduced women's hot flashes by 57 percent, and black cohosh, which decreased the bothersome symptoms 34 percent. Hormone therapy drove down hot flashes 94 percent in subjects given Prempro. A group of 66 women participated in the second study, which found that of the four treatments tested, only Prempro use had a measurable decline in memory as a side effect. Black cohosh and red clover, although no more effective in reducing hot flashes than placebo, had no negative effect on memory, nor on liver enzymes, lipid profiles or measures of breast and endometrial safety. 'Botanicals were safe,' said Stacie Geller, a professor of gynecology and obstetrics at the University of Illinois, Chicago. 'Which is good, because many women will continue to use them.' 