You may experience some or none of the side effects of perphenazine listed in this article. Unfortunately, there is no way for your healthcare provider to know beforehand if you will have side effects from a medicine that you have never tried. Therefore, make sure to let your healthcare provider know if you develop any side effects while taking the drug. You should also let your healthcare provider know if you develop something that "just does not seem right" during treatment. While it may not be a side effect of perphenazine, your healthcare provider will be able to diagnose and treat the problem.