I'm on day 17 of half-dose Tecfidera (after quitting a unhappy relationship with Plegridy). Half an hour after the evening dose, I get a sharp, intense headache on one side of my head. This subsides to a low-level constant headache for the next 12-24 hours. I don't get beetroot-face or GI effects. Is this another variety of flushing? It doesn't seem to fit in the list of side effects from the drug leaflet. Will this get easier after a while? It's not a tolerable side effect for the long - term. I'm going to give it a day off, I think. Does anyone get a similar reaction?