Modafinil (d, l-2-[(diphenylmethyl) sulfinyl] acetamide) [Provigil] is a novel wake- and vigilance- promoting agent that is chemically and pharmacologically dissimilar to CNS stimulants such as the amphetamines, methylphenidate, and pemoline. It is well tolerated and has low abuse liability compared to CNS stimulants.
Modafinal promotes wakefulness. During income tax season it enabled me to work business hours in the U.S. and accommodate international clients as well. It neither enhanced nor inhibited my workouts, appetite, sleep, cognitive performance or relationships with others. Other than headaches, I did not feel any of the side effects others have mentioned.
I tried it a few weeks ago to combat HCV-related fatigue and it did not help. I was wide-awake sure; but, I simply did not have the physical drive to fold a load of clothes. In my case, there is a definite difference between fatigue, sleepiness and being over tired.
There are a lot of elegant and impressive studies related to fatigue and quality of life improvement with conditions such as MS, CFS, Post-Polio, Interferon-induced depression and various cancer treatments to name a few.
There is a post here on Med-Help that shows its effect on various liver enzymes.
http://www.medhelp.org/posts/show/365922
The only suggestion I would make for those considering trying it is to ask for samples first. It can be very pricey even with the best prescription drug coverage.