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