Multiple Sclerosis, or MS, affects over two million people worldwide. The neurodegenerative disease strikes when the immune system attacks myelin, layers of a fatty insulating membrane that surround nerve fibers and help send nerve signals faster. Ari Green, a neurologist at the University of California, San Francisco, has found an over the counter allergy drug called Clemastine that could possibly help repair damaged myelin. “It was originally designed back in the 1970s as an antihistamine and we were excited that it showed the evidence that myelin repair is possible even with injury that is not immediate or acute, but has been there for some time." Green says because of possible side effects of the medication, Clemastine is only a prototype for a better myelin repairing drug that researchers have yet to develop. "What we want is a drug that has a very targeted effect that would be capable of inducing this repair without causing other side effects."