Follow-Up: I have been on Provigil for almost two years after being diagnosed with idiopathic hypersomnia. Before taking it, I would fall asleep anywhere, and my whole being was focused on when I'd be allowed to take a nap! For the first week, I had headaches and felt sick and then my body got used to the medication. When I tried to work up from 200mg to 400mg, as prescribed by my doctor, the higher dosage made me sick to my stomach, so I only take 200mg each day. As long as I get a good night's sleep (8 hours preferably), Provigil works wonders. I have noticed that if I don't get enough sleep, or am very stressed out or drink too much caffeine or take calcium tablets, the effectiveness goes out the window and I am very tired all day. I can still take a nap after I get home from work if I feel the need, which is probably about half the time. Unfortunately, Provigil does not work for everyone. I know someone who had the same reactions you are describing, so he quit taking it and just tries to work through his sleep attacks.