CALORIGENIC POTENCY OF FREE THYROXINE BY MOUTH

Abstract
In a patient with marked myxedema whose basal metabolism was minus 36%, it was necessary to administer at least 50 mg. of thyroxine daily by mouth as the free amino acid in order to maintain a normal level of metabolism. On the basis of these data, thyroxine in this form is about 1/33 as effective as when given orally in the form of the monosodium salt, about 1/90 as effective as when given orally in alkaline soln., and about 1/150 as effective as when given intraven. in alkaline soln.