[Shirazmn]

Provided that I have never used BO myself, what I understand from other people's experience is that it's not "permanent" as in "your body is now constantly flooded by estrogens forever", but it has a long cool-down period after you stop because part of the estrogen in BO is stored in fat. This means that if you stop taking it and your body begins burning through the fat in the new feminine areas in your body (breasts, hips, butt, etc...) some estrogen will be released and the process of reverted fat redistribution will be slower. 
So, while with pharma E and PM your body will flush the estrogen after about one month since the last dosage, IT SEEMS that with BO this process may take a lot longer and poterntially generate some further tissue growth.