Hi Lea--You asked about my Provigil dosage. I started with 200 mgs in the morning. After a month, it was making an improvement, but not enough. My doctor increased dosage to 400 mgs and then finally 600 mg--this seems to be the most effective for me. Again, I also exercise, eat well, take supplements and hormones--thyroid and estrogen and progesterone ( I had a complete hysterectomy). I hope this helps.