In children with a sound heart, the therapy may be started with the entire dose, in adults, the therapy has to be started using small initial doses and gradually increasing to optimum amounts.
Experience has shown that a small dose is also sufficient for patients with a low body weight and patients with a large nodular goitre. (See table.)

Method of administration: The entire daily dose of Euthyrox should be taken in the morning on an empty stomach, at least half an hour before breakfast with some liquid (for example, half a glass of water).
The duration of treatment is generally for life in hypothyroidism and after surgical removal of part or all of the thyroid gland, for some months up to life in the treatment of goitre (euthyroid goitre) and in prevention of goitre recurrence (goitre relapse prophylaxis). In concomitant therapy to treat hyperthyroidism for as long as the drug against hyperthyroidism is taken.
Thyroid suppression test: 14 days before the repeat scan.