Climacterium is marked by hypoestrogenism and it is associated to drastic vasomotors symptoms, genital atrophy and humor alteration. Additionally, these symptoms impair sexual life and life quality. These effects can be counteracted by administration of estrogen therapy. However, estrogen therapy has side effects and isoflavone has been proposed as an estrogen substitute in reposition therapy. The aim of the randomized controlled trial is to evaluate the effects of isoflavone in the sex life assessed by a modified McCoy's sexual questionnaire.