It is difficult to say. DXM rarely caused nausea for me, but I usually did the gelcaps. But on the handul of times I drank syrup, don't remember getting sick either. It often is guaifenesin that causes nausea when people take DXM syrup that contains (I know that's not what you have) but others do report it with straight DXM. A small amount of meclizine or promethazine may help prevent it and I always find Emetrol works great, but it isn't preventative, only helps when you are already nauseous.