Memorial Sloan-Kettering has a page about
the stuff. The page doesn't seem to have been updated with the new information but maybe it doesn't need to be. The page mostly talks about
breast cancer but it does mention prostate cancer too. It outlines hoped-for benefits that haven't been demonstrated in humans. That's still true although the stuff is looking pretty good for mice.
tinyurl.com/abp97jaThe stuff is available on the dietary supplement market but is a quite expensive. There appears to be only one company selling it and they sell it in bottles of 60 for around $130 bucks. Since the directions say to take four capsules once or twice daily one would go through it pretty fast.