I would go with a mix in a 4:1 ratio, just like armour thyroid. So in your case, that would translate to using 50 mcg T3 alongside the 200 mcg T4. You would be on a relatively high dose already then though so just adjust both if you find you're dosing too high. (tachycardia, fever like feeling, sore throat, hindred breathing, too rapid weight loss come to mind)