Removing barriers to vital thyroid hormone (L-T3) could improve outcomes

Summary

Mary Saunders is a patient with hypothyroidism. In this blog she outlines her patient safety concerns relating to the restricted access of a synthetic hormone called L-T3. Mary calls for clarification and an urgent review of current guidance, to make sure that patients who need L-T3 can access it safely and consistently. 

Content

Background

A person with a healthy thyroid system produces adequate levels of a hormone called triiodothyronine, or T3. Having adequate levels of T3—not just in the bloodstream, but down to the cellular level—is essential for good health. A deficiency can lead to a chronic condition known as hypothyroidism (underactive thyroid).

From 1891 to the mid-20th century, the only available treatment for hypothyroidism was desiccated thyroid extract (DTE). This contained, in a natural dried form, the main thyroid hormones—tetraiodothyronine (LT4) and triiodothyronine (LT3).  As a natural animal-derived product, DTE required processing facilities, and was subject to seasonal restrictions.

However, in the 1970’s another synthetic hormone called levothyroxine (T4) was welcomed as a major breakthrough. It eliminated the need to harvest and process animal thyroid tissue and offered several advantages: accurate dosing, predictable potency, and a long half-life that allowed for once-daily dosing. As a result, liothyronine (L-T3) became largely side-lined.

Restricted access to L-T3

Since the 1970’s, most hypothyroid patients have been treated with levothyroxine (T4) alone. However, it has become clear that some people are unable to convert this efficiently, leading to them feeling unwell. For these patients, a combination therapy with liothyronine (L-T3) may be required.

Unfortunately, in 2016, access to liothyronine (L-T3) became severely restricted in the UK after it was de-branded and entered the generic market. Pharmaceutical companies dramatically raised the price—by approximately 6000%—prompting NHS budgetary concerns. In response, NHS England questioned the cost-effectiveness of liothyronine (L-T3) treatment.

Following public outcry and investigation by the Competition and Markets Authority (CMA), the companies responsible faced significant fines, and the cost has since dropped. However, stigma and resistance toward liothyronine (L-T3) remain entrenched in certain prescribing policies. Despite its essential role in human physiology, access continues to be tightly controlled.

The patient safety concerns

Without sufficient levels of T3, these individuals face worsening health outcomes. An underactive thyroid leads to a slow metabolism, fatigue and adversely affects the brain, heart, muscles, mood - T3 is needed in every cell in the body.

NHS England (NHSE) currently has two main documents concerning liothyronine prescribing. One advises clinicians not to prescribe it, while the other permits its use in certain cases—either as a trial or continuation therapy under specialist supervision.

Issued simultaneously in 2023, these contradictory guidelines have caused significant confusion. Most Integrated Care Boards (ICBs) continue to follow the more restrictive policy, leaving many patients without access to this life-changing medication. This is resulting in real and avoidable harm.

Urgent review needed

Despite widespread concern, efforts to prompt policy change have so far failed. Countless letters have been sent by thyroid support groups, Members of Parliament, and individual patients calling for clarification and an urgent review of the current guidance. The goal is simple: to ensure that patients who genuinely need liothyronine (L-T3) can access it safely and consistently.

These appeals have not yet led to any meaningful change. In the meantime, patients continue to experience preventable and often serious harm due to inadequate treatment.

Share your experience

Have you had challenges accessing medication you need to prevent worsening of a condition or symptoms? Or perhaps you are a healthcare provider with insights to share around safe prescribing processes and policies? Get in touch with our editorial team at [email protected] or comment below to share your thoughts. 

About the Author

My name is Mary Saunders. I am a hypothyroid patient - initially diagnosed in 2008. I have had a relentless struggle to be properly diagnosed with my less common form of hypothyroidism. It has been especially challenging to be prescribed the appropriate treatment, and I constantly have to justify why I need it. I am a member of Improve Thyroid Treatment, an online thyroid campaign group.