Liothyronine

The standard treatment for hypothyroidism is levothyroxine (or L-T4) tablets which are safe and very effective. Most people respond within weeks of starting this treatment and report improved wellbeing and reduction in the common symptoms of hypothyroidism, e.g. tiredness, feeling cold, muscle aches and brain fog. However, medical professionals recognise that a small proportion of people will continue to suffer from symptoms despite normal blood test results and adequate treatment with levothyroxine.

If your symptoms have clearly not benefitted from treatment with levothyroxine, and other possible causes have been ruled out, you may be referred to an endocrinologist (specialist thyroid doctor) for further investigations. They may decide to begin a trial of liothyronine (L-T3) /levothyroxine (L-T4) combination therapy. The trial should be supervised by an accredited endocrinologist after a fully informed and understood discussion of the risks and potential adverse consequences. 

L-T3 is not recommended in pregnancy since it does not cross the placenta and there is a risk that the baby will not receive the correct amount of thyroid hormone to develop properly. It is also not recommended for children.

Read our patient leaflet on liothyronine

BTA/SfE joint consenus statement on the prescribing of liothyronine - June 2023

Read more about the prescribing of liothyronine