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Liothyronine tablets and capsules

Liothyronine is a replacement thyroid hormone. It is used to treat the more severe conditions in which the thyroid doesn't produce enough thyroxine.

You will need regular blood tests to check your thyroid levels, particularly at the beginning of this treatment.

If you experience any side-effects, speak with your doctor, as your dose may need adjusting.

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About liothyronine

Type of medicine

A thyroid hormone

Used for

An underactive thyroid gland

Also known as

Liothyronine sodium

Available as

Tablets, capsules

If you have an underactive thyroid gland, it means that your thyroid does not produce enough thyroid hormone. This is a condition known as hypothyroidism. Liothyronine restores the balance of thyroid hormone in your body. It is similar to thyroxine, the hormone which your body produces naturally. Although a medicine called levothyroxine is usually prescribed in preference to liothyronine for people with this condition, liothyronine is given when a fast action is needed, as it works more quickly.

Before taking liothyronine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking liothyronine it is important that your doctor knows:

  • If you have heart or blood vessel disease, or a high blood pressure.

  • If you have either diabetes (diabetes mellitus) or diabetes insipidus.

  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine.

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How to take liothyronine

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about liothyronine and will also provide you with a full list of the side-effects which you could experience from taking it.

  • Take liothyronine exactly as your doctor tells you to. It is usual for your doctor to give you a small dose (such as ½-1 tablet a day) when you first take liothyronine, and then for your dose to be gradually increased to two or three tablets daily, taken spaced out throughout the day.

  • Take the tablets with a drink of water. You can take liothyronine either before or after meals.

  • If you forget to take a dose, take it as soon as you remember. Try to take the correct number of doses each day but do not 'double up' to make up for any missed doses.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor so that your progress can be monitored. You will need regular blood tests to check your thyroid levels, particularly in the early stages of your treatment.

  • Continue to take the tablets until your doctor tells you to stop.

  • If you have diabetes you may need to check your blood glucose more frequently as these tablets can affect the levels of sugar in your blood. Your doctor will advise you about this.

  • If you are due to have an operation or any dental treatment, please tell the person carrying out the treatment that you are taking liothyronine.

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Can liothyronine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with liothyronine. You will find a full list in the manufacturer's information leaflet supplied with your medicine. Experiencing side-effects may be an indication that your dose needs adjusting, so speak with your doctor if you experience any of the symptoms listed below.

Liothyronine side-effects

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting)

Eat little and often. Stick to simple foods


Drink plenty of water to replace lost fluids


Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know

The sensation of having a 'thumping' heart (palpitations) or chest pain

Let your doctor know about this as your dose may need adjusting

Feeling restless or shaky, flushing, sweating, difficulty sleeping, high temperature (fever), loss of weight, cramps, temporary loss of hair (in children), itchy rash

If any of these become troublesome, speak with your doctor

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.

How to store liothyronine

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

If you buy any medicines check with a pharmacist that they are safe to take with your other medicines.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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