This is the only time I'm glad that something isn't quite right. Not rare, nor unusual but non the less not right. Have just had DIO2 test results back which confirms polymorphism and better on T3/T4 combo. I'll stick with T3 only. Will give GP a copy of result. Hopefully more ammo in case our CCG decide I don't need it. I'm sure all of you in the know will burst my bubble as I haven't started researching it yet but for now am convincing self that everything is going to be ok and celebrate with a glass of wine.