Studies on TSH for those on combined T3 T4 therapy

[Lilacsocks]

Does anyone know of any studies assesing the risk of low or suppressed TSH for patients on a combination T3 T4 therapy.

Thanks

[jimh111]

I did a post that shows levothyroxine monotherapy is associated with greater risks than combination therapy, see healthunlocked.com/thyroidu... . Generally if TSH is suppressed (by highish hormone levels) risks are increased.

[Lilacsocks in reply to jimh111]

Extremely interesting and helpful. Thank you.

[McPammy]

Not sure about what studies say. I do know that if you’ve had thyroid cancer endocrinologists insist you have a suppressed TSH. My sister is in this group of people. Her endocrinologist has never explained any dangers of suppressed TSH. I’m on combined T3 and T4 medications for my Hashimotos. I manage to keep my TSH just within range by adjusting very slightly my Levothyroxine dose. I’m on liquid Levothyroxine which makes this doable. I don’t alter my T3 dose. I’ve never felt so well in over a decade being in combination treatment finally after years on Levothyroxine only.

[Gilbo72]

Lilacsocks Yes! would like to know too. Maybe a slightly different take on it, as I have recently been given a T4 /T3 trial on the NHS, but my heart sank when I read the letter to the GP that said ‘our aim would be to keep TSH within the reference range with a generous level of FT3 concentration…’

I am also looking for any studies on TSH and T3 to prove that it is irrelevant. (Rather than a risk)

I found this very interesting article, which lists some studies at the end, which basically is about the Father of the TSH test admitting that something else was at play with TSH when adding T3…

thyroidpatients.ca/2019/03/...

And this article/transcript/video…

thyroidpatients.ca/2019/03/...

I’m not sure if this is what you are after, but I would like more like this to wave at my endo when I go back and he finds my TSH suppressed. (It was always suppressed on T4 as well).

There is a theory that your TSH set point can permanently change, I would love to find more evidence on that. Especially after restricted calories. ( well I developed autoimmune thyroid problems following 1 year of anorexia, followed by 2 years of bulimia, followed by a near fatal birth experience, followed by a bout of pleurisy, all during a VERY stressful time in my life. So I fully believe if my autoimmune system can turn on my body, my body set level, including TSH can also change, just need to find some evidence….

[Lilacsocks in reply to Gilbo72]

Hi Gilbo,

This is interesting, it seems like we are in the same boat!

I am getting by ish on levo with a supressed TSH, top end T4 and T3 at about 30% but have just also been prescribed a trial combination therapy.

My worry is that they will try and bring my TSH back into range at that will leave me unwell.

I am also interested to hear others experience on what happened to TSH level once lio was added in.

I'll have a read of the links you've shared, thanks.

[Gilbo72 in reply to Lilacsocks]

Lilacsocks ah! Excellent! We are indeed both in the same boat. I am about 4 weeks in my trial. I was on 147mcg of Levo a day, which they dropped to 100mcg and have added 10mcg of T3. The difference was like a light switch in the fact in clarity and mood and inclination and hugely improved sleep. However, I do get very tired. Keep falling asleep. But it's a much nicer exhausted/well earned tired feeling rather than the everyday lethargic exhaustion. My TSH was always suppressed, my T4 was around 28 (top of range was 20) and my T3 has been recently in the minus, ie under range. They told me they would go up to 20mcg, but I am due to see them in a couple of weeks following another blood test. I am looking for evidence to show that they should not be checking my TSH now I am on T3 to show them at my next appointment. What have you been prescribed, and where in the Uk are you? (just out of interest). It would be funny if we were under the same care and hit them with the same info!

[Lilacsocks in reply to Gilbo72]

That would be funny! I the consultant I'm under is at Macclesfield (am I allowed to say who?) I think he also has a clinic at wythenshaw because I was under his care during pregnancy. I live in cheshire. Where are you?

I am on 125mcg levo and his has proposed dropping that to 75mcg with 10mcg lio twice a day.

[Gilbo72 in reply to Lilacsocks]

Ah thats a shame, I am the other end of the country. Surrey Heartlands CCG. So it sounds like the same approach. Drop by 50 T4 and add 20 T3. Mine did say start with 10 (split into 5, twice a day) and build up to 20. It would be good to keep notes to see how it all goes...

[Lilacsocks in reply to Gilbo72]

Yep, good to be hear you have responded positively so far. I am a bit anxious about making the change!

[Gilbo72 in reply to Lilacsocks]

Yes I was too. But I prefer feeling like this then before, but I won't lie, I am falling asleep by 8pm. Which is nice, I actually look forward to going to bed and sleeping rather than avoiding it as I would lie for hours and hours trying to sleep.

I did find the first week difficult. It crossed my mind to up the T4 again, or take more T3.

In that first week I tried taking it all in one go in the morning, then trying a bit at night, I finally settled on one dose at waking and one about now. Seems to work. At the moment I am only pottering around the house. The minute I do anything more strenuous I am more tired (6-7pm) , so I'm guessing I need an increase, which I am tempted to try myself.

Just one thing to note. I can't remember who, but someone here posted a link to all the available 20mcg tablets available in the UK and their prices. I think the months supply ranged from £97 to £250. It turns out the Boots in the hospital ordered the most expensive brand. So I will bring that up with the Endo too. I don't want any reason for my trial not to turn into long term.

[Enfrance in reply to Lilacsocks]

Hello Lilacsocks. Your situation sounds alot like mine so I thought I would reply to your thread. I am currently on 125mcg of levothyroxine (T4) and 25mcg of liothyronine (T3) after years of being on T3 only. My TSH is suppressed at approximately 0.01 and both my T4 & T3 and the beginning of the range.

Thyroid panel: May 5, 2022

TSH 0.01 Range 0.55-4.78

Free T4 0.99 Range 0.89-1.76

Free T3 1.88 Range 2.30-4.20

As per my Endo. I added (in addition to the 125mcg T4 and 25mcg in the AM) 25mcg of T3 every 12 hours.

However, I gained over 2 kilos in less than 2 weeks and I was very swollen and achy.

I returned to the 125mcg of T4 and 25mcg of T3 and I am waiting of my next thyroid panel to see what happened??