In the 1970s, treatment with thyroid extract was superseded by levothyroxine, a synthetic l
form of tetraiodothyronine. Since then, no major innovation has emerged for the treatment of …

Background: Fourteen clinical trials have not shown a consistent benefit of combination
therapy with levothyroxine (LT4) and liothyronine (LT3). Despite the publication of these …

In the 1990s, selenium was identified as a component of an enzyme that activates thyroid
hormone; since this discovery, the relevance of selenium to thyroid health has been widely …

Thyroid hormone (TH) is required for normal development as well as regulating metabolism
in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially …

Background: A number of recent advances in our understanding of thyroid physiology may
shed light on why some patients feel unwell while taking levothyroxine monotherapy. The …

Thyroid hormone (TH) molecules enter cells via membrane transporters and, depending on
the cell type, can be activated (ie, T4 to T3 conversion) or inactivated (ie, T3 to 3, 3′-diiodo-l …

Hypothyroidism is a common condition of thyroid hormone deficiency, which is readily
diagnosed and managed but potentially fatal in severe cases if untreated. The definition of …

The deiodinase family of enzymes mediates the activation and inactivation of thyroid
hormone. The role of these enzymes in the regulation of the systemic concentrations of …

Objective Hypothyroidism has multiple etiologies and manifestations. Appropriate treatment
requires an accurate diagnosis and is influenced by coexisting medical conditions. This …

Background: Approximately 15% more patients taking levothyroxine (LT4) report impaired
quality of life compared to controls. This could be explained by additional diagnoses …