By Medically reviewed by hellodoktor

Generic Name: Liothyronine Brand Name(s): Liothyronine and Liothyronine.


What is liothyronine used for?

Liothyronine is a thyroid hormone. It works by supplementing the natural thyroid hormones in the body.

Liothyronine is commonly used for treating an underactive thyroid (hypothyroidism), other types of thyroid problems (such as types of goiters, thyroid cancer), myxedema coma or pre-coma (life-threatening symptoms caused by low thyroid levels).

It may also be used for other conditions as determined by your doctor.

How should I take liothyronine?

Liothyronine is usually given as an injection at your doctor’s office, hospital, or clinic. If you will be using liothyronine at home, a health care provider will teach you how to use it. Be sure you understand how to use liothyronine. Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.

Do not use liothyronine if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.

Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.

How do I store liothyronine?

Liothyronine is best stored in the refrigerator. To prevent drug damage, do not freeze. There may be different brands of liothyronine that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush liothyronine down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using liothyronine?

Before using this drug, tell your doctor if:

  • You are allergic to any ingredient in liothyronine.
  • You are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement.
  • You have allergies to medicines, foods, or other substances.
  • You are planning to have surgery.

There is important safety information you may notice:

  • Check with your doctor if you experience trembling or shaking of the hands, nervousness, difficulty sleeping, headache, change in appetite, diarrhea, weight loss, increased sweating, increased sensitivity to heat, increased heart rate, chest pain, or shortness of breath. These symptoms may mean that your dose needs to be adjusted. Do not adjust your dose or stop taking liothyronine without checking with your doctor.
  • Diabetes patients: Liothyronine may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
  • Lab tests, including thyroid function tests, may be performed while you use liothyronine. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Use liothyronine with caution in the elderly; they may be more sensitive to its effects.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using liothyronine during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking liothyronine. Liothyronine is pregnancy risk category A, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Liothyronine is found in breast milk. If you are or will be breastfeeding while you use liothyronine, check with your doctor. Discuss any possible risks to your baby.

Side effects

What side effects can occur from liothyronine?

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome:

  • Fever
  • Pain or irritation at the injection site
  • Twitching

Seek medical attention right away if any of these severe side effects occur:

  • Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue)
  • Chest pain
  • Fast or irregular heartbeat

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with liothyronine?

Liothyronine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, including:

  • Estrogen or oral contraceptives (birth control pills), because they may decrease liothyronine’s effectiveness.
  • Anticoagulants (e.g., warfarin), ketamine, tricyclic antidepressants (e.g., amitriptyline), or vasopressors (e.g., epinephrine), because their actions and the risk of their side effects may be increased by liothyronine.
  • Insulin, oral hypoglycemics (e.g., glipizide), or digitalis glycosides (e.g., digoxin), because their effectiveness may be decreased by liothyronine.

Does food or alcohol interact with liothyronine?

Liothyronine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with liothyronine?

Liothyronine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • Heart or blood vessel disease (e.g., angina)
  • High blood pressure
  • An overactive thyroid
  • A long-standing condition of underactive thyroid
  • Untreated thyrotoxicosis (high thyroid levels)
  • Untreated adrenal cortical problems (e.g., Addison disease)
  • A history of heart attack


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using liothyronine.

What is the dose of liothyronine for an adult?


The initial dose is 25 mcg PO qDay; may increase by 25 mcg q1-2Weeks; not to exceed 100 mcg/day.

The maintenance dose is 25-75 mcg PO qDay.

May use 10-12.5 mcg T3 in combo with T4 (decrease T4 dose by 50 mcg).

Nontoxic Goiter

The initial dose is 5 mcg PO qDay; may increase by 5-10 mcg q1-2Weeks (5 mcg in elderly).

When reach 25 mcg PO qDay, may increase by 12.5 mcg or 25 mcg q1-2Weeks.

The maintenance dose is 75 mcg PO qDay.


The initial dose is 5 mcg PO qDay; may increase by 5-10 mcg/day q1-2Weeks.

When reach 25 mcg PO qDay, may increase by 5-25 mcg q1-2Weeks.

The maintenance dose is 50-100 mcg PO qDay.

Myxedema Coma

The initial dose is 25-50 mcg IV.

Patients with CVD: The dose is 10-20 mcg IV.

Doses of at least 65 mcg/day IV associated with lower mortality.

Allow 4-12 hr between doses; not to exceed 12 hours.

What is the dose of liothyronine for a child?

Congenital Hypothyroidism

The initial dose is 5 mcg PO qDay; may increase by 5 mcg q3-4Days.

The maintenance dose is:

  • <1 year: 20 mcg PO qDay
  • 1-3 years: 50 mcg PO qDay
  • >3 years: 25-75 mcg PO qDay

Nontoxic Goiter

The initial dose is 5 mcg PO qDay; may increase by 5-10 mcg q1-2Weeks.

When reach 25 mcg PO qDay, may increase by 12.5 mcg or 25 mcg q1-2Weeks.

The maintenance dose is 75 mcg PO qDay.

How is liothyronine available?

Liothyronine is available in the following dosage forms and strengths:

  • Liothyronine injectable solution 10mcg/mL

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of liothyronine, contact your doctor immediately.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: March 18, 2017 | Last Modified: September 12, 2019

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