Regarding lasting effects...
Don't take my word for it, do your own checking around but this is what I believe.
When talking about herbs, the lasting effects are any breast growth that you got. It may go down a bit but it may not.
I think that once the herbs clear your body, your male hormones start coming back and everything eventually gets to where it was before you started.
According to many reports, taking breaks does not make you start over from square one. Many people say that when they re-start, their growth is faster.
I think that it is NOT recommended to take any other phytoestrogens with PM, so maybe do not use Fenugreek with PM, but I may be wrong.
IMHO Fenugreek, Fennel and Red Clover are probably the safest yet very effective phytoestrogens. You can take any one of them or any combination of them safely.
They each have their own special character and it would not be crazy to take one cap of each, as a daily regimen.
BO is a Glandular, not an Herb. It is much different from herbs. It does not contain any estrogen. It changes your body chemistry and that change can be permanent.
For your purposes... stay away from BO.
Karen