I just had some adverse side effects on my third day of taking tecfidera. All the common side effects and then a seizure. My doctor does not want to think that the seizure is from tecfidera; however, I have read about others who had seizures. Please report these side effects to the FDA (number will vary according to your state--just Google it) and to Biogen-800-456-2255. Everyone needs to know about these side effects. Thanks so much for your help!