Liothyronine is used to treat hypothyroidism (a condition where the thyroid gland does not produce enough thyroid hormone). Liothyronine is also used to treat goiter (an enlarged thyroid gland) and to test for hyperthyroidism (a condition where the thyroid gland produces too much thyroid hormone). Liothyronine is in a class of medications called thyroid agents. It works by supplying the thyroid hormones normally produced by the body.

Currently, there is not enough evidence from clinical studies to support the use of liothyronine, alone or in combination with other medications, as the first choice of therapy to treat hypothyroidism.

Side Effects Of Liothyronine

Liothyronine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • weight loss
  • nervousness
  • excessive sweating
  • sensitivity to heat
  • temporary hair loss (particularly in children during the first months of therapy)

Some side effects can be serious. If you experience either of the following symptoms, call your doctor immediately:

  • chest pain
  • rapid or irregular heartbeat or pulse

Warnings & Precautions

Before taking liothyronine:

  • tell your doctor and pharmacist if you are allergic to liothyronine, thyroid hormone, levothyroxine, any other medications, or any of the ingredients in liothyronine tablets. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants (‘blood thinners’) such as warfarin (Coumadin, Jantoven); diabetes medications taken by mouth; digoxin (Lanoxin); estrogens; insulin; oral contraceptives containing estrogen; and tricyclic antidepressants such as amitriptyline (Elavil). Many other medications may also interact with liothyronine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • if you take cholestyramine (Questran), take it at least 4 to 5 hours before or 4 to 5 hours after you take liothyronine.
  • tell your doctor if you have adrenal insufficiency (condition in which the body does not produce enough of certain natural substances needed for important functions such as blood pressure) or thyrotoxicosis (condition that occurs from too much thyroid hormone or hyperthyroidism). Your doctor will probably tell you not to take liothyronine.
  • tell your doctor if you have or have ever had diabetes; cardiovascular disease such as high blood pressure, atherosclerosis (hardening of the arteries), chest pain (angina), or irregular heartbeat, or have ever had a heart attack.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking liothyronine, call your doctor.
  • if you have surgery, including dental surgery, tell the doctor or dentist that you are taking liothyronine.

Liothyronine Dosage

Liothyronine comes as a tablet to take by mouth. It usually is taken once daily. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take liothyronine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of liothyronine and gradually increase your dose not more than once every 1 to 2 weeks.

To control the symptoms of hypothyroidism, you probably will need to take this medication for the rest of your life. Continue to take liothyronine even if you feel well. Do not stop taking liothyronine without talking to your doctor.


Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to liothyronine.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking liothyronine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.