When already taking Topamax, how long (months) do you need to cycle off before going back on to experience weight loss again? I am on Topamax 150 a day for migraine but it's the botox injections that help me. I lost 10lbs in the first 3 or so months on it and 5 more gradually but it plateaued. I've probably been on for a year or two. I read the weight loss is in the first 3 mainly and then stops after a year. I would taper off/back on of course.