The effects of Chinese medicinal herbs on postmenopausal vasomotor symptoms of Australian women - A randomised controlled trial

Objective: To evaluate the effects of a defined formula of Chinese medicinal herbs (CMH) on menopausal symptoms. Design: A double-blind randomised placebo-controlled trial. Methods: Between August 1998 and April 1999, 55 postmenopausal Australian women recruited from an urban population completed 12 weeks of intervention with either a defined formula of CMH (n=28) or placebo (n=27) taken twice daily as a beverage. Main outcome measures: The primary end-point was change in frequency of vasomotor events (hot flushes and night sweats). The secondary end-points were changes in score for the domains measured in the Menopause Specific Quality of Life (MENQOL) Questionnaire. Results: There was a reduction in average weekly frequency of vasomotor events with CMH (-15%, 95% CI, -31% to +1%) and with placebo (-31%, 95% CI, -42% to -21%). The difference between groups favoured the use of placebo; however, this was not significant (P=0.09). Although significant reductions in scores for the various domains of the MENQOL Questionnaire were observed for both CMH and placebo, there were no significant differences between the two treatment groups for any domain. There was evidence for effect modification by previous use of natural therapies for the vasomotor, physical and sexual domains of the MENQOL Questionnaire: women with no prior use of natural therapies for their menopausal symptoms responded to therapy, whereas prior users did not. Conclusions: The defined formula of CMH was no more effective than placebo in reducing vasomotor episodes in Australian postmenopausal women, or in improving any of the four symptom domains in the MENQOL Questionnaire. Three of the MENQOL Questionnaire domains were modified by prior use of natural therapies. This finding has implications for future studies.