Propylthiouracil is not a hormone, it is a drug that can act on the thyroid system, its main mechanism of action is to be able to inhibit the peroxidase system in the thyroid gland, which can inhibit the synthesis of thyroid hormone. After taking propylthiouracil, the synthesis of thyroxine is inhibited, so it is suitable for use in the treatment of hyperthyroidism when it is able to inhibit the synthesis of thyroxine, and thus used in the treatment of hyperthyroidism. This medication is often a drug used in the treatment of hyperthyroidism, but it is not a hormone, so there is no need to worry about hormone-related adverse effects.