Hi Cailin,
Many people say that the side effects are nausea, vomiting, sometimes headaches and diorrea. But I didn't really have any of that, only a tiny bit of nausea (not much) and maybe a couple of stomach aches, but that was only in the first 2 weeks. Most dr's start you at 500mg so you get used to it, then increase it, thus minimising the side effects.