I've been on rebif since april 30. I'm currently on the high dose 44. I'm handling the side effects pretty well, practically no flu like effects anymore. But it doesn't seem to be doing anything to the # of my attacks. I basically get an attack every 1 - 1.5 months. Most of them just give me numbness, with mild perm damage(fingers crossed that it stays that way). How long does Rebif take to work?, my neuro wants to give it until the end of summer. Then a mri to see if I have new lesions or not.