My TSH has always been very very low ie <0.01 as I have been on thyroxine now for 40 years. I saw an Endo privately on Dionne's list who initially said it would be low as it is suppressed due to the thyroxine, which I have always understood. The problem now is he seems to have changed his mind and has advised my GP that I may be on too much thyroxine due to this TSH reading and to monitor my next bloods with this issue in mind.
This Endo said, "the patient's T4 was right at the top of the range but within normal although TSH remains suppressed but this may be a long term effect of being on slightly too much thyroid replacement and not reflecting the current status. I am hoping that this next blood test will reveal a higher TSH".
I am getting my bloods done tomorrow at 9am. Whatever time I go my TSH has always been <0.01. I have had my heart scanned and had my pituitary checked and all is ok. I also had a Dexa scan and my loss at aged 60yrs is 6%. So it looks like it isn't having a detrimental effect.
On this blood test form there isn't a T4 request only Free T3 and TSH. My last Free T3 was 3.7 (no ranges included in my letter!). My free T4 was 22.3 (no range again!)
My GP is prepared to add the Free T4 onto the blood request form but would I be better leaving it out as if my free T4 is high they will definitely lower my thyroxine?
I feel ok at the moment, better than I did a few years ago, I think I was struggling with post-menopausal symptoms then and severe stress as my daughter was very ill. I get a bit tired at times but they are doing a FBC and checking my ferritin tomorrow too.
I am on 125mcg thyroxine. When I was alternating on 125/150mcg in December 2021 my blood test results from a different hospital were TSH 0.01 (0.27 - 4.2), Free T4 26.7 (10.5-24.5) and Free T3 4.3 (3.1-6.8)
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Pinkpetite
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Low TSH doesn't cause heart problems or osteoporosis, anyway. It's high T3, as in Grave's that does that. And, if your TSH has been 0.01 for 40 years, it's hardly likely to rise now, no matter what you do, because the HPT axis has been down-graded. Why can't they understand all that?
According to those December 2021 results, you are a very poor converter, so lowering your levo will probably make you ill due to the FT3 also decreasing - and all for nothing! So, unless they are prepared to reduce the levo and add in T3, you probably are better off not getting the FT4 tested!
… or high T4 that causes cardiac problems and osteoporosis. Only pointing it out because the research indicates T4 has more harmful effects than T3 (through non-genomic actions).
I wrote about the link between thyroxine (from thryoid or tablets) and cardiac risk / reduced life expectancy here healthunlocked.com/thyroidu... .
We tend to only consider cardiac effects from T3 binding to thyroid hormone receptors ('genomic' activity) as this is the main action of thyroid hormone. However, T4 in particular has non-genomic action where it is the active hormone. These non-genomic actions of T4 can be harmful.
T4 also has some poorly understood actions on bone formation. I've seen a paper linking T4 to osteoporosis but can't find it. This study academic.oup.com/jcem/artic... shows that T3 and T4 have similar actions on bone formation, some of the T4 action will be genomic, T4 being converted to T3 in or near the bone. My best judgement is that T3 and T4 affect bone formation and fracture risk with little difference between them.
We should also remember that TSH promotes bone formation, it is better to have a healthy TSH - if we can.
Yes, but there's nothing hard and fast, is there. Risks and associations compared to a miserable life with low FT3 and the 'risks and associations' connected with low T3. Until the medical profession get their act together and start prescribing T4+T3, we don't have a lot of choice, do we.
Have you written 'T3' when you mean 'T4' in the above?
It's difficult to gather evidence as there is a strong bias against T3 and so few studies are done, in case they bring bad news that goes against endocrinologist doctrine.
The Rotterdam Study jamanetwork.com/journals/ja... has some hard facts "Compared with those in the lowest tertile, the difference in life expectancy for men and women in the highest FT4 tertile was −3.2 (95% CI, −5.0 to −1.4) and −3.5 (95% CI, −5.6 to −1.5) years, respectively, of which, −3.1 (95% CI, −4.9 to −1.4) and −2.5 (95% CI, −4.4 to −0.7) years without CVD." Consequences of the non-genomic actions of T4.
Have you written 'T3' when you mean 'T4' in the above?
No. If you're a poor converter, needing your FT4 high in range, to give you just a low level of FT3, and you reduce the levo, the FT3 is going to fall as well as the FT4. And it's low T3 that causes symptoms. So why would I have meant to say 'T4'?
And it's this strong bias against T3 that makes most research pretty meaningless.
That makes sense. I provide evidence that high normal T4 promotes cancer and is associated with cardiac and possibly bone disease. Hence, we should push for combination therapy rather than using high normal fT4 in an attempt to get adequate T3. I know this is difficult, I'm just supplying the evidence that shows it is more important than we used to believe, that we should push harder.
Your endo. is somewhat correct although a high fT4 within its reference interval can be too much and suppress TSH. You would probably be better off with a little T3 and less T4.
No one will give me T3 and the Endo did say it's really hard to get the dosage right, and with the NHS it's just going to be too stressful, the Endo wouldn't do it. Should I get the T4 added to the test or just do the TSH and T3 as is on the form? I'm worried my Gp will reduce my dose if the T4 comes up high again - it never has been so high before - it's a bit of a risk!
I'm in London. The Endo I saw was on Dionne's list so it was a shock when he started focussing on my TSH. He doesn't tend to prescribe T3 as he said it was so hard to get the dosages right. I will email thyroid UK again. If anyone can private message me if they have seen a good Endo in London who prescribes T3 I would appreciate it. Thank you.
Sorry for late reply. Not sure what is the best way forward, I would tend to leave it at TSH and fT3 and reserve any form adjustments for when they might make a big difference.
I have exactly the same, although no endo involved, just a TSH obsessed GP.
I've been on Levo since 1975 and been keeping a record of my results since around 1995ish and TSH has always been suppressed, always comes back as <0.005, 0.005, < 0.01 or <0.02 depending on which lab does the test. Totally freaks out the GP.
No amount of Levo alleviated my symptoms, just kept pushing FT4 higher and higher and I eventually discovered myself that I was a poor converter so self sourced T3 and have been adding it to a lower dose of Levo since 2015. TSH obviously still suppressed but FT4 and FT3 always well within range, I find around 60-70% through range for both is about right for me, so I point out these levels to my GP and say I can't be overmedicated. It doesn't make any difference, she still claims I am overmedicated but I refuse to try and get TSH into range just to satisfy a number she wants to see. The only person at the surgery who completely understood about my suppressed TSH was the Advanced Nurse Practioner who said the feedback loop obviously is no longer working considering how long I'd been on Levo and he was always happy with my FT4 and FT3 being his guide. Unfortunately he's now left
Reading about TSH obsessed doctors always puts me in mind of flat earthers. No matter how much evidence you put to them that the earth is a sphere, they don't believe you. No matter how many patients point out that FT4 and FT3 are the crucial markers, they always bang on about TSH.
Why is there such a lag between how doctors are taught about thyroid and upto research on how thyroid replacement actually works.
I saw a good quote the other day:
Doctor "are you telling me an hour of Google outweighs my 6 years of medical school"
Patient "are you telling me a 10 minute consultation outweighs my 20 years of living with this condition?".
I'm guessing you just get your prescription and only take what you need with the T3 you source? How did you manage to work out how much T3 you needed? I did get some a few years ago but got palpitations on it, I did start off very slowly. Is there a guide somewhere? Just in case I felt to try again.
I'm guessing you just get your prescription and only take what you need with the T3 you source?
Yes. GP doesn't know I take T3. I get my Levo prescription but don't take the full amount.
How did you manage to work out how much T3 you needed?
Started low, very very gradually increased, testing after each increase and noting how I felt. It's trial and error and lots of patience is needed. I got up to 31.25mcg T3 at one time but by tweaking Levo and T3 am now settled on 12.5mcg T3.
Is there a guide somewhere? Just in case I felt to try again.
No not really. Just start with 1/4 of a tablet, lower Levo a couple of weeks before if necessary (depending on FT4 level), and then very gradually increase by only 1/4 of a tablet at a time, waiting 8 weeks, testing, noting how you feel. Also optimise nutrient levels before starting T3.
I think the biggest issue with Drs, even in the US, is that they are trained in medical school for a very short time, on thyroid management (which, I believe, was actually paid for by the makers of Synthroid 20 years ago!) The studies the American Thyroid Association use have been found to be poorly sourced and many of the associations, including the FDA have pharmaceutical companies on their boards, so they are very biased. I am so thankful for Drs and endos that are "in it" to actually help the patient. I'm fortunate to have a wonderful GP that listens. Thank you for allowing me to join your group. My step sons wife is a Brit and very involved in functional therapy and holistic medicine. So nice to be on a site that doesn't just push the narrative, rather than help.
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