Thyroid Suppressibility After Therapy for Thyrotoxicosis*

Seventy-six thyrotoxic patients were studied by means of thyroid suppression tests (using thyroxine or triiodothyronine) after treatment with radioactive iodine. They were grouped according to the various intervals after therapy. Significant suppression of thyroid function was demonstrated as early as six weeks after treatment with radioiodine. There was close correlation between the degree of suppression achieved and the final clinical status of the patient. Suppressibility, absent in the thyrotoxic state, returns when the patient is rendered euthyroid.