My personal opinion when people have had a thyroidectomy, is that they should either be prescribed T3 only or T4/T3 combo. This is an excerpt from a Research Paper re the equvalence and if you cursor down to Page 80 on the left-hand top column.
Dose Selection in T3/T4 Study RCTs
The second logical basis for a conclusion
is the actions taken, i.e., the doses given to the
subjects. Most subjects received T3 below its
adult starting dose of 25 mcg/day.
The subjects in RCTs received T3 in some ratio to the
withdrawn T4. The various RCTs used T4:T3
ratios of 14:1, 10:1, and 5:1. Subsequent re-
search by the US National Institutes of Health
(NIH) found the therapeutic equivalence was
Thus, most of the subjects were under
treated with the T3/T4 combination. In light
of the NIH finding, the conclusion that T3
therapy is never needed is invalid.