Euthyrox is the trade name of Levothyroxine Sodium Tablets, which is commonly used in the replacement therapy of hypothyroidism. The thyroid gland is an important endocrine organ in the human body and synthesizes thyroid hormones, which play an important role in promoting metabolism. In hypothyroidism, the synthesis of thyroid hormones is reduced, and symptoms such as chills, fatigue, slow response, depressed mood and memory loss may occur. Levothyroxine Sodium Tablet is a synthetic hormone, which can supplement the thyroid hormone that the body lacks and improve the symptoms. Levothyroxine Sodium Tablets can be used not only for the treatment of primary hypothyroidism, but also for secondary hypothyroidism after thyroidectomy. Individual daily dosage should be determined under medical supervision based on clinical examination. Levothyroxine sodium tablets should be taken as a single 1-day dose with water half an hour before breakfast. Normally, patients with hypothyroidism and after partial or total thyroidectomy should take the medication for life. Patients should go to the hospital regularly for rechecking of thyroid function and adjust the dosage of the drug under the guidance of the doctor according to the results of the examination.