I've been on tysabri 2 and a half years. I have gain 4 stone since starting tysabri. I've watched closely and each month I have infusion I gain half a stone not happy fed up being 15 stone. Thinking of having a break from tysabri and see what happens. I exercise as best I can I eat healthy (no chocolate sweets crisps bread ) I used 2b 9 and a half stone. I can't do this anymore