Levothyroxine is the main thyroid hormone that your gland would make if it could. Levothroid is just a name brand of the generic levothyroxine. Synthroid, Unithroid, Levoxyl are some others. All the same thing, different brands.

You may do just as well on the name brand as you did on the levoT, but you could do either better or worse, too. There can be differences in the way you absorb it, or in the way your body uses it. Be sure to let your doctor know if you experience the return of any hypothyroid symptoms.