Welcome to our community! I started on my Avonex back in 1997. I was diagnosed clinically probable because I only had 1 lesion but enough other diagnostic criteria to make that diagnosis. My last MRI, last year, still just showed the one lesion. My neuro and I have talked about whether we are looking at the wrong thing here since my MRI is unchanged. But late last year I had an episode of optic neuritis. So she is confident that I do have MS. But back to the original question. Does it work? I sure don't want to go off of it and see if it doesn't. Over 12 years and the MRI is the same. I'll stay on it.