Héctor F Escobar-Morreale et al.
The Journal of clinical endocrinology and metabolism, 90(8), 4946-4954 (2005-06-02)
Combined infusion of levothyroxine plus liothyronine, as opposed to levothyroxine alone, is the only way of restoring the concentrations of circulating TSH, T4, and T3 as well as those of both T4 and T3 in all tissues of thyroidectomized rats.