Follow-Up: I can't say enough good about this medicine. I've tried dexedrine, ritalin, etc., which sortof worked, but left me jittery, but I could just sleep faster in the afternoon! My doc switched me to Provigil, and it truly has crossed the T's and dotted the I's in my life. I am awake, aware, and no more afternoon comas. I accomplish so much more, without effort, and would recommend anyone whose doctor recommends it to truly give it a try. I have had no side effects, other than a slight headache, which has faded after a month or so. I seem to do fine on 100 mg. a day, but if I have something important to do, I do increase the dosage to 200 mg in the morning, and 100 mg at about 1:00. It has been a miracle for me. I hope it works for you as well. Finally, after 50 years, I am a normally functioning human being. Also, it does not interfere with nighttime sleeping for me. Actually, I sleep better at night now. Good luck