This prescription drug (sold under brand names such as Levothroid®, Levo-T®, Levoxyl®, Synthroid®, Tirosint® and Unithroid®) treats hypothyroidism. That's a condition where your thyroid gland doesn't make enough thyroid hormone. We also use this drug during treatment for thyroid cancer. Levothyroxine belongs to a class of drugs we call "hormones."
How does it work? Levothyroxine comes as a pill or a capsule. Usually, you take it once a day. Levothyroxine replaces the thyroid hormone that your body is lacking.
Levothyroxine does have side effects such as weight gain or weight loss. It can cause changes in appetite. It can cause things like headaches, vomiting, diarrhea and hair loss. Ask your doctor for a full list of side effects. Also, you should know that this drug may not be safe to use if you have certain drug allergies. If you're taking other drugs or supplements, your doctor may need to change their doses. And we may need to watch you closely to see if levothyroxine causes any issues. Before taking this medication, make sure your doctor knows about all medical conditions you have and all medications and supplements you are taking, both prescription and over-the-counter.
Levothyroxine can be helpful for many people when used correctly. So read all the instructions and warnings. Take it only as directed. For more info, talk to your doctor.