You may experience some or none of the side effects of TriNessa listed in this article. Unfortunately, it can be difficult to tell whether any particular side effect (such as nausea) is caused by TriNessa 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 TriNessa, your healthcare provider will be able to diagnose and treat the problem.