BBC UK TV segment on hypothyroidism is re-broadcast by TVO in Canada

A five-minute documentary segment on the topic of hypothyroidism is found in the BBC UK TV series “Trust Me, I’m a Doctor,” season 6 episode 2. It was first aired in the UK on February, 2017. The segment is part of the show’s larger discussion of the question, “Can we boost our metabolic rate?”

It has just been re-broadcast in Ontario, Canada on the TVO television network in Ontario — yesterday, April 12, 2023.

Since the ideas of this UK TV show are being disseminated in Canada, it’s timely to feature it on our blog.

To aid discussion of its content, I provide material for international readers and for Canadians who are unable to access the episode after it is no longer available after May 11, 2023.

In this post, I’ll provide:

  • A summary of the episode’s section on hypothyroidism,
  • The full transcript of the 5-minute segment, including verbal descriptions of some video,
  • Occasional “NOTE” boxes with updated information and corrections, given that it was first aired in 2017,
  • Selected still image clips from the show.

At the bottom are some Canadian and UK links to the show’s episode.

NOTE: These excerpts constitute ethical “fair use” and “fair dealing” within many international copyright laws (for example, see The British Library’s web page on fair dealing in UK copyright law) for the purpose of review and non-profit public education.


The show’s host, Dr. Michael Mosley, interviews a patient, Jo Parker, and Dr. Anthony Toft, the former president of the British Thyroid Association. The segment starts at 15:20 minutes.

Mosley argues that there are many questions and controversy on topics related to the thyroid, and that hypothyroidism affects mainly women. The documentary explains in a rather simplistic way how TSH, T4 and T3 interrelate and work in the body. A significant portion of hypothyroid patients respond poorly to levothyroxine (LT4) alone.

While leading opinions are changing, and Dr Toft believes that eventually hypothyroidism will be treated with both T3 and T4, the price of T3 has gone up far beyond its true cost, and medical practices and scientific research are not happening fast enough.

The slow pace of scientific research, rigid interpretations of TSH, and the inflated T3 market price in the UK are making UK doctors reluctant to prescribe T3. It is driving some desperate UK patients to take risks ordering T3 tablets online from foreign countries and to self-medicate.

The show features thyroid patient Jo Parker, who explains her former hypothyroid symptoms and her symptom relief by taking T3 hormone. Mosley questions her whether T3 is merely having a placebo effect. She answers that if it is a placebo, it’s extremely effective and has given her life back.

The show’s short thyroid segment concludes by saying that many of the symptoms of hypothyroidism can be caused by other health issues and dietary choices. If blood tests results are normal, one may still investigate further. But Mosley emphasizes that one may simply have to admit that hormone treatment is not for them, and look into lifestyle changes instead.


[With verbal description of video, by Tania S. Smith]

15:12 [Mosley] We’re going to take a look into another aspect of our metabolism that many of you have told us you’re concerned about. On “Trust Me” we get a lot of questions about the thyroid.

15:22 This is a gland in your neck that produces hormones, which regulate your metabolism and is vital for your health. The thing is there’s a lot of controversy about the treatment and diagnosis of issues related to the thyroid. So, how do you know if you’ve got a problem, and what can you do about it?

15:39 [Mosley browses his laptop, which shows the British Thyroid Foundation website.] The thyroid gland is a bit like the accelerator pedal on your car. It produces hormones that speed your metabolic rate right up. If that doesn’t happen, then your metabolic rate will slow right down. . And it’s a finely tuned machine.

NOTE: The thyroid hormones do much more than this. They are not just upregulators of metabolic rate. “Thyroid hormone affects virtually every organ system in the body, including the heart, CNS, autonomic nervous system, bone, GI, and metabolism.” (Read more in “Physiology: Thyroid hormone,” Shahid, Ashraf & Sharma, 2022.)

16:01 First your body needs to produce what’s called thyroid stimulating hormone or TSH [Shows gas pedal being depressed, car speeding up], which tells your thyroid to get working. Next your thyroid releases hormones into the blood, mainly one called T4.

Later, T4 is converted in our tissues to T3, the active hormone that revs up our metabolism in our cells. [Video of foot on gas pedal]

NOTE: No, T4-T3 conversion is not all delayed to “later.” T4-T3 conversion occurs within the human thyroid gland itself. Thyroid gland tissue expresses the richest concentrations of deiodinase type 1 and type 2 enzymes (D1, D2) that perform T4-T3 conversion (Human Protein Atlas, see “Tissue RNA expression of DIO1, DIO2, and DIO3“) See also Kawasaki et al, 2019: “TSH is known to regulate D1 and D2 expression in the human thyroid gland at the transcriptional level, through the TSH receptor”).

Hypothyroid patients

16:26 [Video of larger-sized bodies older adult shoppers walking on the street in coats]

But sometimes the thyroid doesn’t produce enough hormones. This is known as hypothyroidism. The result is normally a slower metabolism. Now, it affects around one in a thousand men, but it’s more common in women, affecting one in fifty.

NOTE: Here are updated UK rates for “treated” hypothyroidism: “The prevalence of treated hypothyroidism increased from 2.3% (1.4 million) to 3.5% (2.2 million) of the total British population between the years 2005 and 2014 and is projected to rise further to 4.2% (2.9 million) by 2025.” “There were increases observed in both men and women (from 2 to 3.2% and 8 to 9.3%, respectively)” (Razvi, Korevaar, Taylor, 2019)

16:41 [Video of patient Jo Parker turning on her gas stove]

Sufferers put on weight and have other common symptoms, as Jo Parker experienced. [Jo Parker stirring soup]

16:49 [Jo Parker speaks] The most prominent symptoms were the fatigue and the cold. At the same time were hair loss, [and] migraines five days a week. [Parker being interviewed in her living room] Low mood — I wouldn’t say clinical depression, but low mood.

17:01 [Mosley speaks; Video shows Jo standing in front of a house, with a gentle smile. She appears to be in her 50s and in good health now, not overweight or suffering.] Jo’s symptoms were caused by an underactive thyroid, but getting it diagnosed was a struggle.

17:08 [Video of other unidentified women, one black, in their 20s to 70s standing and looking into the camera] And there are thousands more women in the UK with symptoms like Jo’s who feel they haven’t been properly diagnosed. One of the problems likes in the way the activity of the thyroid is measured.


17:18 [Video of blood draw] If you have symptoms of hypothyroidism, your GP will test your blood. The telltale sign they’re looking for is high levels of thyroid stimulating hormone, TSH, together with low levels of the main thyroid hormone, T4.

[Image of blood, superimposed on it two bars, one on the left labeled “high TSH” with a bar rising higher, and one on the left, labeled “low T4” with a bar falling lower.] It sounds straightforward, but it isn’t.

17:37 [Images of people walking on streets with coats on] What are considered normal levels of these hormones varies around the world and the threshold for diagnosis in the UK is higher than many.

17:50 [Image of Dr. Toft walking along a canal toward the camera] Doctor Anthony Toft is former President of the British Thyroid Association.

He thinks the test results are sometimes interpreted too rigidly, and that results which fall just within the limits of the normal range can merit further investigation. [Toft takes a seat at an outdoor table at a restaurant with Mosley, as juice/water glasses are delivered]

18:07 [Toft speaks.] If the T4 is right down at the lower limit of normal, the TSH is up at the upper limit of normal, that’s suspicious.

[Mosley is shown listening, nodding. Toft speaks again] So, that’s the prompt to take it a little further. I think the trouble is there isn’t enough, um, debate about the interpretation.


18:20 [View of Mosley at a laptop scrolling the Thyroid UK website and HealthUnlocked forum. Mosley speaks] If you are diagnosed with an underactive thyroid, then you will most likely be prescribed a synthetic version of T4.

[Image of box of “Levothyroxine Tablets” with a pile of white capsules in front of it] This works for the majority of patients, but in around 10% of cases, the symptoms don’t improve.

NOTE: Estimates of the percentage vary widely depending on the study and its methods. “persistent symptoms … occur in 5% to 15% of hypothyroid patients despite treatment with levothyroxine (LT4)” despite a normalized TSH (Wiersinga, 2021)

18:40 [Mosley continues. Images of people walking on street] One reason might be because some patients can’t convert T4 into the active hormone T3.

NOTE: False. There is no such thing as a person who “can’t convert” T4 to T3. This is easily proven, since people without T3-secreting thyroid glands who are treated with LT4 hormone alone will have T3 levels in circulation. However, some LT4-treated patients are “poor converters” who are less efficient at converting T4 to T3. One objective sign of poor conversion is a low FT3/FT4 ratio (Midgley et al, 2015).

[Image of box of Tiromel tablets, 25 mcg, with some capsules resting on top] T3 hormone in tablet form does exist, but price is a problem in the UK.

18:52 [Toft speaks at the outdoors cafe table] The cost of T3 has escalated incredibly. It’s now about 300 pounds for two months’ supply of T3, whereas it costs pennies to make. [Mosley] So, if I go along to my GP and ask for T3 there’s a good chance he’ll say no it’s too expensive? [Toft] Yes.

NOTE: As of 2023, the cost of LT3 (liothyronine, synthetic T3) has reduced considerably for 2 months’ supply. For example, the website lists Liothyronine tablets by AAH Pharmaceuticals Ltd, 20 mcg, 28 tablets, is £ 51.54, so two months would be £103.08, which is near 1/3 the price estimated by Toft in this 2017 documentary.

NOTE: A PDF of guidance dated June, 2019 from the UK Regional Medicines Optimisation Committee (RMOC) permits patients to be referred to an endocrinologist who can prescribe them LT3 / liothyronine on the NHS. “In rare situations where patients experience continuing symptoms whilst on levothyroxine (that have a material impact upon normal day to day function), and other potential causes have been investigated and eliminated, a 3 month trial with additional liothyronine may be appropriate. This is only to be initiated by a consultant NHS endocrinologist.”

19:10 [Mosley speaks while a bottle of 1000 Tablets of “Thiroyd” is shown] There is a less expensive thyroid supplement taken from animals. It contains both T3 and T4 hormones, but it isn’t licensed in the UK.

[Image of US brands of prescription-only animal-derived (porcine) desiccated thyroid: Armour Thyroid tablets, USP, by Forrest Pharmaceuticals, St Louis, MO, 1 1/3 grain (90 mg), Each tablet contains levothyrxoine (T4) 57 mcg, liothyronine (T3) 13.5 mcg, next to a bottle of Nature-Throid, 2 grain (130 mg), Thyroid USP, 100 tablets. On the left is a bottle of NP Thyroid, another US brand that is no longer available.]

19:21 [Sitting at the outdoor cafe, Mosley asks Toft,] So, do you think most patients should have T4 and T3?

[Toft answers, smiling mildly, raising eyebrows] I suspect, that in time, that’s what will happen. The trouble is, the evidence base is not as strong as we would wish it to be, but I suspect it’ll be a long time before we have sufficient evidence.

19:37 [Video of someone browsing a website of a page titled “Getting a diagnosis and Starting Treatment”, from the Thyroid UK website. Mosley speaks.] Many doctors won’t prescribe T3, and there are patients who choose to buy pills online from abroad.

[Jo Parker is facing us while typing on a laptop resting on her lap, and the video shows a web page of the “internationalpharmacy” website, with an image of a liothyronine pharmaceutical bottle].

Self-medicating is always risky, and taking T3 in large doses may cause side effects in the long term, such as heart problems. But like many women, Jo has accepted these risks. [image of foreign drug bottles in foreign languages circulating on a turning platform]

NOTE: As of 2023, long-term “side effects” of “taking T3 in large doses” such as “heart problems” have yet to be quantified in publications of human clinical research. In 2018, Tariq et al published a retrospective chart review of 100 patients from 2010 to 2016 on animal-derived and synthetic T3-inclusive therapy, “Effects of Long-Term Combination LT4 and LT3 Therapy for Improving Hypothyroidism and Overall Quality of Life.” They reported, “we did NOT identify additional risks of atrial fibrillation, cardiovascular disease, or mortality in patients of all ages with hypothyroidism.”

Symptoms and quality of life

19:58 [Mosley and Jo Parker converse, seated in her living room. Parker says] On balance, I think I will go with what I feel the best.

[Mosley is shown listening, looking skeptical, not nodding or smiling, and then the camera shows Parker talking again] If I am at an increased risk of anything, at least I’m living my life to the full [Parker sighs], rather than being locked indoors, overweight, cold, not able to function mentally.”

[Mosley is shown talking, asking her] Have people suggested to you that this is simply the placebo effect?

[Parker is shown answering] I can only say one thing, if it is a placebo effect, I am the best I’ve been in all my life, and shouldn’t that be good enough? [smiles, gives a small laugh]

20:25 [Video shows women on the street, standing, looking at the camera, holding signs with words on them like “Fertility issues,” “Memory loss,” “Muscle & joint pain,” “Anxiety & depression,” “Dry skin,” “Chronic fatigue,” while a saxophone plays. Mosley speaks]

The diagnosis and treatment of hypothyroidism is tricky. The same symptoms can be caused by a number of factors, such as stress, depression, and a poor diet.

NOTE: As of 2023, UK National Institute for Health Excellence (NICE) recommendations do not dismiss patients with multiple thyroid symptoms. Instead, they caution against putting too much weight on 1 symptom: “Consider tests for thyroid dysfunction … if there is a clinical suspicion of thyroid disease, but bear in mind that 1 symptom alone may not be indicative of thyroid disease.” (NICE, “Thyroid disease”; Nov 2019, sec. 1.2.1)

NOTE: Multiple thyroid symptoms and signs are more strongly indicative of a need for investigation. See a concise list of symptoms and signs of hypothyroidism in Physiology: Thyroid hormone,” Shahid, Ashraf & Sharma, 2022.


20:38 [Mosley is shown speaking while looking into the camera] If you’ve had a blood test and the results have come back normal, then you can investigate it further.

NOTE: As of 2023, in the UK, if the TSH is normal in an untreated person, NICE guidance permits further testing of TSH and FT4 only if there is suspicion of secondary hypothyroidism (pituitary disease) (NICE, “Thyroid disease”; Nov 2019, sec. 1.2.9)

[He takes a quick breath in, as if in a rush to add] But you may also have to accept the medication is not for you and that lifestyle changes may be more appropriate.

[Image of person tipping random tablets and capsules out of a drug bottle and they bounce on the table]


Available until May 11, 2023, the Canadian TVO Video (not viewable from UK): TVO Today (Director).

An article on on Thyroid in 2017 was published by the show’s host, Dr. Mosley, including a link to the episode:

If you’re in the UK, here is a link offered by a UK patient, but “it is time limited on iPlayer & this episode is not currently available”:

5 thoughts on “BBC UK TV segment on hypothyroidism is re-broadcast by TVO in Canada

  1. Thanks for this post. I have tried several times to contact Dr Moseley to ask him to do a series about thyroid disorder and highlight the controversies and injustices we face, as well as the history of treatment which has plenty of drama about it, but to no avail. He has done some fascinating series, “Medical Mavericks” was excellent. Perhaps if more people contact him he might be moved to do something on our behalf. I tried via Twitter but it wasn’t successful. His family suffer from diabetes so he’s more interested in that I think

    1. His wife is a GP so he will get the establishment view of hypothyroidism and believe that the blood test is infallible

  2. So the blood tests are only useful if you respond to the medication in the way the medics like? Otherwise you are on your own?

  3. Having dealt with the near criminal level of ignorance and greed prevalent throughout the UK Medical powers-that-be I was fortunate enough to find one GP who helped guide me towards T3 (self) treatment. He did this even while defending himself legally against false accusations of malpractice levelled by the surgery he worked out of. They felt he was prescribing too high of doses of T4 which he based on symptoms rather than exclusively on blood tests.
    I’ll leave it there other than to say that he continues to fight the good battle and thanks to him I can continue refining my T3 only treatment (I now live in France)
    Best to all

Leave a public reply here, on our website.

This site uses Akismet to reduce spam. Learn how your comment data is processed.