Wellbutrin is pretty safe when taken as prescribed even long term however sometimes although rare some people may experience side effects when taking Wellbutrin such as allergic reactions and seizures.
Other less severe long term side effects when taking Wellbutrin are headaches, dry mouth, nausea, insomnia, constipation, and dizziness which are the most common adverse less severe side effects of taking Wellbutrin long term.
If you do experience the above listed side effects of taking Wellbutrin then you should speak with your doctor and if you had seizures or other allergic reactions then that would be more severe and a doctors visit or urgent care or emergency room visit would be recommended.
Most people take Wellbutrin as prescribed by their doctor without any problems however some people do rarely experience some problems and side effects when taking certain medications including Wellbutrin.