How to take Tecfidera. Take Tecfidera exactly as your doctor has prescribed Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended. You may take Tecfidera with or without food. Taking the medicine with food may help prevent flushing (warmth, itching, or burning sensations). Do not crush, chew, break, or open a capsule.