Personally, I experienced pretty major nausea and vomiting. I also experienced a lot of muscle weakness, particularly in my legs since, at the time, my rsd was simply in my legs. They'd also spasm more than usual when I was on neurontin. I switched to Lyrica though shortly after, and after a week of my body adjusting to it, I had no problems whatsoever. I've been on it for about 5.5 years and still haven't had any issues with side effects of the medicine. However, I know some who have problems on Lyrica and not neurontin, so it varies with each person.