I recently got my dose increased to 250 of nuvigil because it was not lasting and I was still struggling to stay awake. I was wondering if anyone else felt like it has a on and off effect. Let me explain like its working well and a couple of hours later your fighting sleep then it begins to work again later? I know I sound crazy but this is my experience I have been having and I wounder if any one else might be feeling that way too. I would apperciate your input on this. I just wanted to say I think this group is awsome and I really like the support that is given to each other here.