Hi!! This is my first response. I have had MS for 7 yrs. Been on Avonex, Copaxone, double avonex, and Novantrone. Now only on Tysabri. I really liked it. Have had 2 infusions and ready for my third. Just a once a month injection which takes an hour and then they watch you for another hour with a saline drip. I drink gingerale when I get it because after the first inj., I was a little nauseated on the way home. If you would have an allergic reaction (hives, etc.) they will stop the program for you. It seems very safe, but not all insurance cos will pay for it. It is the only drug that I know of that helps protect us some. I love it and feel very blessed to get to take it.