If you start off at 200-250 mgs ed, anywhere from 10 to 30 days. Have a clean diet, add lots of fruit for the vitamins and minerals, stay hydrated and do your research, you can easily lose a pound per day. You will want to eat everything in sight so you might want some sort of appetite suppressant with it, which will also help with energy. Also add a packet a day of emergen-c powder for a vitamin boost. You will be hot all the time. When your mood turns to shit, your muscles ache and you have no desire to get off the couch its probably time to come off. You'll retain water on it so your final result will be best around the 3rd day after you stop taking it.
To sum it up....eat good, start at 200-250 mgs ed, stay hydrated, and do your research....lose a lb per day.