I WAS on Levoxyl for 4 months, I started getting a numb feeling in my feet and legs, pain in my neck and a rapid heart beat. After seeing the doctor about my symptoms he thought I had MS and ordered a brain and spine MRI - the tests were negative for any brain tumors or MS, I decided to take myself off the drug. I've heard of horrible things happening to other people, even death as a result to side effects!!! Do yourself a favor and stop taking the drug if it's causing you serious side effects.