The dose of propylthiouracil varies significantly depending on the patient’s condition, and the lowest effective dose should be selected for hyperthyroidism during pregnancy. The instructions for propylthiouracil clearly state that pregnant women should choose the lowest effective dose of propylthiouracil, as failure to do so may result in neonatal hyperthyroidism and goiter. During pregnancy, especially during the 10th to 14th week of pregnancy, when the production of thyroid hormones in the fetus begins, the use of the drug must be carefully supervised by a doctor. Adverse reactions to this drug include neutrophilia, granulocyte deficiency, liver damage, rash, and itching. It is contraindicated in people who have been treated with propylthiouracil with granulocyte deficiency, as well as liver damage, and patients who experience blood changes, elevated transaminases and cholesterol must use the drug under the supervision of a doctor. If you are allergic to propylthiouracil, you should not use this product. Propylthiouracil should be used under medical supervision when hyperthyroidism is present during pregnancy and should not be taken on its own to avoid serious adverse reactions.