Levothyroxine
Levothyroxine is a man-made version of the thyroid hormone thyroxine. You take it once a day, usually for life. It is safe when taken at the right dose.
You will usually start on a low or medium dose, which is then adjusted based on blood tests.
How to take it
- take it at the same time every day, usually first thing in the morning
- take it on an empty stomach with water, and wait 30 to 60 minutes before eating or drinking coffee
- keep it at least 4 hours apart from iron tablets, calcium, indigestion remedies and some other medicines, as these stop it being absorbed
- if you miss a dose, take it when you remember, unless it is nearly time for the next one
Tell your pharmacist if your tablets look different from usual. A small number of people notice a difference when they change brand.
Blood tests
- after starting or changing your dose, you will have a blood test after about 6 to 8 weeks
- once your dose is right, you will usually have a test once a year
It can take a few months to feel fully better.
Side effects
Side effects usually only happen if the dose is too high. Signs include a fast or irregular heartbeat, feeling shaky or anxious, sweating, diarrhoea and trouble sleeping. Tell your GP if you get these.
Other treatments
Liothyronine (T3) is not usually recommended on the NHS. A specialist may prescribe it in some cases. Natural or "desiccated" thyroid products are not recommended, because the amount of hormone in them can vary.
Next, read about living well with an underactive thyroid.
Common questions
What if I still feel tired on levothyroxine?
Tell your GP. They will check your blood levels and may adjust your dose. They may also check for other causes of tiredness, such as low iron, low vitamin B12 or low vitamin D, which are common alongside thyroid problems.
Sources we used
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