Hundreds of thousands of people in the UK may be unnecessarily taking drugs

Hundreds of thousands of people in the UK may be unnecessarily taking drugs for an under-active thyroid, study warns

  • Studies show that patients given the daily drug levothyroxine get no benefit
  • The experts behind the BMJ review examined data from 21 studies
  • Common symptoms of an under-active thyroid include fatigue and weight gain 

Hundreds of thousands of patients with underactive thyroids are being prescribed a drug that offers no benefit, research suggests.

The drug levothyroxine is offered to people with thyroid problems to treat symptoms such as depression, feeling cold, tired and having muscle aches.

More than 32 million prescriptions for the hormone replacement drug were issued by NHS England last year, but experts have now said it is unnecessary and does not help relieve symptoms.

A study in the British Medical Journal (BMJ) concluded that ‘almost all adults’ with an underactive thyroid ‘would not benefit from treatment with thyroid hormones’.

Figures from NHS Digital show that more than 32 million prescriptions were issued in England in 2018 for levothyroxine. This is up from 20,426,378 in 2008

The thyroid gland makes a hormone which helps control energy levels and growth. Common symptoms of an underactive thyroid are fatigue, feeling cold, weight gain and depression.

Current guidance from the National Institute for Health and Care Excellence (Nice) says the condition should be treated by taking levothyroxine, a daily hormone replacement tablet.

Figures from NHS Digital show that more than 32 million prescriptions were issued for the drug in England in 2018, up from 20,426,378 in 2008.

Once people are on the drugs, they usually have a blood test once a year to monitor their hormone levels.

Experts behind the new BMJ review, including from hospitals and universities in Norway, Switzerland, Canada and Belgium, examined data on more than 2,000 people from 21 studies.


An underactive thyroid gland, known as hypothyroidism, occurs when the thyroid gland doesn’t produce enough hormones.

Common signs of the medical issue include tiredness, weight gain and feeling depressed.

An underactive thyroid can often be successfully treated by taking daily hormone tablets to replace the hormones your thyroid isn’t making.

There’s no way of preventing an underactive thyroid. 

Most cases are caused either by the immune system attacking the thyroid gland and damaging it, or by damage to the thyroid that occurs during some treatments for an overactive thyroid or thyroid cancer.

Figures suggest around 15 people in every 1,000 women in the UK and one in 1,000 men.

They said levothyroxine hormones ‘consistently demonstrate no clinically relevant benefits for quality of life or thyroid-related symptoms, including depressive symptoms, fatigue and body mass index’.

They recommended that the drug is unnecessary, and said their findings ‘may substantially alter prescribing trends’.

Professor Helen Stokes-Lampard, Chair of the Royal College of GPs, said the evidence was ‘powerful’ but patients should not stop taking prescribed medication.

‘Prescribing is a core skill for GPs and we will always aim to take into account the physical, psychological and social factors potentially affecting a patient before recommending any form of medication – as well as taking into account relevant clinical guidelines,’ she said.

‘Thyroid hormones are powerful drugs and GPs will only ever prescribe them if we think they are of genuine benefit to the person sitting in front of us, particularly as it usually means taking the tablets and being monitored in the long-term.

‘If evidence shows that they are not going to be of benefit to our patients, it is important that we know this and that it is reflected in the clinical guidelines that inform our decision-making.

‘The authors make a powerful case based on emerging evidence, and it is important that this new research is taken on board as clinical guidelines are updated and developed, in the best interests of our patients. 

‘It is also important that patients do not suddenly stop taking their thyroxine medication, but that they discuss this with their GP at their next routine medication review.’