Just wondering how many years people have been taking Tecfidera. I've been taking Tecfidera for a little over 5 years. No changes in MRI scans or mobility. I'm very active and walk about 15-18 miles a week. I've been fortunate to be in very good shape. Not sure if this is due to the medication or would I be this way without it. I'm not sure any doctor could answer that question. I'm about to ask my neurologist what he thinks in a few weeks.