Synthetic or a Natural Thyroid Replacement: Should the Choice be Left to the Patient?

Data from National Health and Nutrition Examination Survey (NHANES 1999-2002) reveals 3.7% prevalence of hypothyroidism in the general population [1]. 10.3 million People or 4.6% of those surveyed reported use of thyroid hormones (levothyroxine, liothyronine, or desiccated thyroid) [1]. Desiccated Thyroid Extract (DTE) of animal origin has been used to treat hypothyroidism since 1892 [2,3]. Several authors have previously raised questions about standardization of levothyroxine (T4) and L-triiodothyronine (T3) in thyroid extract [3]. The switch to a more expensive synthetic preparation, sodium L-thyroxine, had been advocated in the 1960’s [4].