I have been on Imunovir four times since 2006, each time for six months duration. The first time I took it, I had a decent response to it in that I got back much of my energy but still had the reddened irritated throat. My immune system crashed after eight months of stopping it when I returned from vacation. Each time I took it thereafter, I had a poorer response from it; only getting some more energy but no relief from symptoms, otherwise. Since I have CFS and fibromyalgia, I think that the Imunovir significantly increased my body pain, especially when I was on the week which required taking 500mg (two tabs) three times a day. I now think that my diminishing response could be due to the fact that my body is becoming resistant to the immune modulating mechanism of the medication. So the next time I take it, I plan a course of therapy with three months on the medicine and one month off, then another three months on and one month off. I will also reduce the second week of three grams a day Monday through Friday to three grams on Monday, Wed. and Fri. and 1.5 grams on Tues. and Thurs. to help reduce the overall body pain. In fact, I did the reduction of dose the last time I took it and was not in quite as much pain as before.