I have been taking Provigal for probably about 5 months now. I started off thinking that I had found a miracle drug - just one pill in the morning and I felt great for the rest of the day. I don't know if I have built up a tolerance or if my fatigue has just gotten a lot worse, but now I am up to 4 pills a day on most days (2 in the morning and 2 around lunch time). It still helps me a little, but not nearly as much. It is better than nothing though. The only problem with Provigal is it is VERY expensive - 30 pills cost around $385. I had to fight with my insurance company to get it covered and once they did approve it, they only approved 30 pills a month (enough for 1 a day). From what my dr office has told me there aren't many insurance companies that will pay for it at all, so I was lucky that I at least got that much. Fortuneately for me, my dr was really good about keeping me supplied with samples while I was waiting for the approval.