Thyroid hormone receptor alpha (THRA) is a nuclear receptor that mediates the biological effects of thyroid hormones (T3 and T4) by regulating gene expression involved in metabolism, growth, and development. As a member of the thyroid hormone receptor (TR) family, THRA exists as two major isoforms (TRα1 and TRα2) generated by alternative splicing, with TRα1 binding thyroid hormones and TRα2 acting as a dominant-negative regulator. THRA antibodies are tools used in research to detect and study the expression, localization, and function of these receptors. They play a critical role in elucidating THRA's involvement in physiological processes and diseases, such as resistance to thyroid hormone (RTH), cardiovascular disorders, and cancers. Monoclonal or polyclonal THRA antibodies are employed in techniques like Western blot, immunohistochemistry, and immunofluorescence. Dysregulation of THRA signaling is linked to developmental defects and metabolic syndromes, making these antibodies valuable for diagnostic and therapeutic research. Recent studies also explore THRA's role in aging and tissue regeneration. Ensuring antibody specificity is crucial, given the structural similarities between THRA and other TR isoforms like THRB. Overall, THRA antibodies are essential for advancing our understanding of thyroid hormone pathways and their clinical implications.