[Randomized, double-blind crossover study of bioavailability of levothyroxine].

Objective: The synthetic thyroid hormone levothyroxine-sodium (LT4) is still the treatment of choice to replace thyroid hormone deficiency in hypothyroidism, and for adjuvant treatment of euthyroid goiter. A change of LT4 preparations during treatment may lead to major changes of thyroid hormone levels. In this study, we compared the bioavailability of two LT4 preparations, L-Thyroxin Henning 100 and Eferox 100.