I didn't stop taking it all together, but did start taking it every other day. So far, I still have the same trouble with my brain fog, but it may take awhile to leave your system. I haven't talked to my dr. about doing the "every other day" thing, but will next time I see him. I'm a little afraid of stopping altogether as it does stop the estrogen. However, my sister in law had the same cancer and it made her so tired, she laid down in the street and fell asleep! They got her up and onto the sidewalk. She stopped taking it and is doing fine and that was quite a few years ago. She is in her 80's now.