Hi Jennifer. Well, in my opinion... Ty doesn't seem to work for me, however thousands of people are benfiting from it. The thing that I do like about it is that I am not getting any of the yucky symptoms that I had from the CRABs. I am concerned about PML, but like Eddie said, I am more concerned with not losing the use of my body. From what I understand, Ty works amazingly well for ON it is one of the first noted improvements. If it works for you, than obviously it is worth the risk. I would say try it for a few months and see how it works.