Our Wellbutrin Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. This is not a complete list of side effects and others may occur. The manufacturer's product labeling should always be consulted for a list of side effects most frequently appearing in patients during clinical studies. Side Effects. Drug information provided by: IBM Micromedex. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Find information about common, infrequent and rare side effects of Wellbutrin XL Oral. Find patient medical information for Wellbutrin XL Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Along with its needed effects, bupropion (the active ingredient contained in Wellbutrin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. “ Side Effects: Insomnia, Aggressiveness, Dry & itchy throat, Coughing, Brain feels tight (if that makes any sense) and so does skin on skull, thinking not 100% clear, mild feeling of depression. The side effects featured here are based on those most frequently appearing in user posts on the Internet. The manufacturer's product labeling should always be consulted for a list of side effects most frequently appearing in patients during clinical studies. Talk to your doctor about which medications may be most appropriate for you. Our Wellbutrin XL (bupropion hydrochloride extended-release) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. In Summary. Commonly reported side effects of bupropion include: insomnia, nausea, pharyngitis, weight loss, constipation, dizziness, headache, and xerostomia.