Levothyroxine is a synthetic thyroid hormone normally produced by your thyroid gland to regulate the body's metabolism and energy. It is administered when thyroid gland fails to produce enough Levothyroxine on its own. Levothyroxine help to treat hypothyroidism which is low thyroid hormone. Similarly, it is also used to treat or prevent goiter, a condition characterized by enlarged thyroid glands, which can be caused by surgery, hormone imbalances cancer or radiation treatment. Note, you may not be in a position to take Levothyroxine if you have certain medical conditions. Inform your doctor in case you have an untreated adrenal gland disorder, thyrotoxicosis which is a thyroid disorder, or if you have recent symptoms of a heart attack.