I've done two rounds of cell cept - each 2-4 years, and only stopped because it stopped working. But when cell cept worked it was effective and I didn't experience any side effects other than suffering during the slow build up to full dose. Once I had the full dosage it was an easy med to tolerate. Of course, with lupus, all of our bodies react differently.
I have been on Cellcept since 2003. The only side effect at the beginning was a little nausea. The good thing is that my nephritis is in remission!