I took phen years ago and lost 30 lbs. I stopped when I got down to goal. However, I didn't like the sleepless nights and the anxiety attacks (they kept me up too). But I stuck with it because I liked the feeling of not wanting to eat.
I tried it again briefly 2 years ago (when I was up 30 lbs again) and it didn't work anymore. I wanted to eat AND I experienced all those bad side effects again. Stopped right away and will not go back to it. I am now heavier than I was when I began taking it the first time. *sigh*
Am I glad I took it in the first place? I don't know. I hope down the line I don't come up with some condition that was brought on because of the pill. I worry about that.