i'm 43 and i've been in perimenopause since i was 35! i suffered badly from hot flashes and night sweats. i now eat tofu daily and i don't have hot flashes. i started eating it daily about a year ago. i don't think it took very long to click in.
if you don't like tofu, there are lots of meat substitute products made with soy; wieners, cold cuts, burgers.
give it a try. it really helped me out.