The main ingredient of levothyroxine sodium tablets is levothyroxine sodium, which is the same as the body’s own secretion of thyroxine, and its main role is to exogenously replenish thyroxine to maintain the normal physiological function of the body. Its indications mainly include: 1. Replacement therapy for hypothyroidism. 2. Simple goiter. 3. Prevention of goiter recurrence after goiter resection. 4. Adjuvant therapy for hyperthyroidism treated with antithyroid drugs. 5. Postoperative suppressive therapy for thyroid cancer. Adverse effects of this drug are commonly associated with drug overdose, manifested by hyperthyroid symptoms such as palpitations (rapid heartbeat, often accompanied by panic), fever, menstrual disorders, insomnia, excessive sweating, weight loss and diarrhea. Therefore, levothyroxine sodium tablets should be taken in strict compliance with the doctor’s instructions, regular review, avoid unauthorized stopping or increasing or decreasing the dosage.