These responses have helped me immensely. I've only begun Rebif about 8 months ago. I do get injection site redness, which then stays looking like a bruise for a week or so. Generally, if I remember to take Tylenol shortly before my injection, I don't usually get any reaction. I have however, experienced awful chills and shaking if I do not remember to take the Tylenol ahead of time (who knew that little anti-inifammatory could really do SO much). I've not yet had any follow-up MRI, and truthfully, I haven't noticed much improvement (YET), but I'm hopeful that my neurologist knows what he is doing. Right now, I'm seriously looking into the CCSVI option as well for more immediate relief and trying to be preactive. I do kinda question what this Rebif is doing to my system; I suppose that's yet to be seen.