Hi Charlie,
In all the years on this site, the only natural remedy that I have heard of that has any sort of health warning is Saw Palmetto.
Even that doesn't actually do you any harm, but it does cause the PSA reading to be reduced, so it is important if you are on any sort of treatment where your PSA level is being monitored as a means of evaluating the success of that treatment to avoid Saw Palmetto.
Other than that you can fill your boots with natural remedies.
My best tip for hot flushes is to get your hair cut shorter, you can quickly lose a lot of heat through the top of your head.
:)
Dave