It is possible that you may experience some or none of the Entocort EC side effects listed in this article. Unfortunately, it can be difficult to tell whether any particular side effect (such as nausea) is actually caused by Entocort EC or other factors. Therefore, make sure to let your healthcare provider know if you develop any side effects while taking Entocort EC, or if something "just does not seem right." While it may not be a side effect of Entocort EC, your healthcare provider will be able to diagnose and treat the problem.