Propylthiouracil is a thioureylene derivative characterized by inhibitory effects on thyroid hormone synthesis through targeting thyroid peroxidase (TPO) and type 1 iodothyronine deiodinase (DIO1) Its mechanistic actions involve suppression of TPO activity disrupting iodine oxidation and subsequent thyroid hormone formation as well as inhibition of peripheral thyroid hormone conversion via decreased DIO1 enzymatic activity In biomedical research Propylthiouracil is commonly utilized to investigate molecular pathways underlying hyperthyroid conditions such as Graves disease as well as to experimentally explore metabolic regulation of thyroid hormones