it does help with hot flashes (the american term for them) and hot flushes, but bear in mind that when you come off hrt you'll get them again. they happen while your hormones are changing and once they've settled down, so will the flushes/flashes. it's worth bearing with it for a while, they get worse before they get better, and for most women they stop altogether once things have settled. as has already been said, some supplements work for some ladies, it's just a matter of finding what works for you. and exercise really does help too, not only with the flushes/flashes but with the weight gain that can happen round this time too.
best of luck.