I used to donate blood occasionally (but wanted to do it more frequently) and wanted to see if I could donate again while taking Rebif. I called to see if I could and said I have MS and I am taking Rebif 3x per week and she said I could not donate. I asked if it was from the drug and she said no it was because I have MS. That really caught me by surprise since I had just assumed it would be the drug to ban me. On the other hand I understand since we don’t really know what causes MS and I don’t want to give it to anyone. If someone really needs blood getting MS would probably be the least of their problems – but my blood type isn’t all that rare (though I am RH- so that does make it more rare but not like B-) so no big deal. Just wish I could help.