Thyroid UK
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Is 10 mcg of Liothyronine as good as a placibo?

I' on 100 micrograms per day of levothyroxine (dropped down 6 weeks ago from 125mc) and at same time went onto 10mcg daily of Liothyronine. The doctor clearly wanted to drop my down to 100 and i refused to be dropped down, so he agreed to put me on 10mcg of Liothyronine if i dropped. However, is this amount as good as a placebo in that it is such a small dosage it is unlikely to do any good? I'm due to see him today (he didn't turn up the first two appointments and registras had to talk to him on the phone!). My test results have not changed at all since six weeks ago. TSH is 0.03 (reason for his insistence that i drop the Levothyroxine), T4 is 17 and T3 is 5.7. I really don't know if i'm tired all the time still as i now take about three teaspoons per day of Guarana which seems to kick me into gear and i have energy now and seem to be back to my bouncy self. However, if it weren't to take such a high intake of caffeine.... Any advice on what i should say to the specialist endo doc today if he turns up at the hospital?

10 Replies

The doctors are recommended to drop levo down by 50mcg and replaced by 10 mcg T3. So I think it is a good compromise that you went down 25mcg and replaced by 10mcg.

My TSH is 0.01 and Dr Toft ex President of the BTA says that some people need to have a suppressed TSH to feel well. Excerpt from Pulse Article

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This ‘exogenous subclinical hyperthyroidism’ is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).

Even while taking the slightly higher dose of levothyroxine a handful of patients continue to complain that a sense of wellbeing has not been restored. A trial of levothyroxine and tri-iodothyronine is not unreasonable. The dose of levothyroxine should be reduced by 50µg daily and tri iodothyronine in a dose of 10µg (half a tablet) daily added.


Thank you for this. My T3 is 5.7. is that too high? you seem to say ref range is 1 to 2.2? From what you are saying, i think i should ask to go back to 125mcg per day to try to get more elevated towards the 24 pmol/l rather than the current 17? I find this (as i'm sure others do) sooooo difficult to understand and am literally scared to see the endo specialist because they make you feel so stupid and i don't trust them at all. Karen



The most important point whilst on thyroid gland hormones is "How do you Feel". If you feel good you are on an adequate dose. If not, you could either be too low or too high. If high you would soon know and drop the dose yourself without seeing the GP.

The quotation I gave is by Dr Toft, as regards the T3 level he states I am not sure whether labs differ on this hormone so I couldn't answer your question. As I have read often, the TSH is not a good guide to adjusting patients doses as people differ. Some may require a higher dose and another a lower dose. It is a guessing game.

This is a link and there are a number of topics at the top of the page and may help understand more. Some of the links within may not work. It is questions/answers.

When you give your blood results you should give the ranges (figures in brackets) beside the actual results as it makes it easier for some to reply. I don't know why labs don't all have the same reference ranges. It would make it much easier.


Thank you. I shall have a good read. The actual Doctor turned up today and he was actually very attentive and made me feel 'cared for'! He's going to do more tests! Thanks again. K


Hi Karen

You should find out what the ref range is for your results as labs can vary.



"TSH is 0.03 (reason for his insistence that i drop the Levothyroxine), T4 is 17 and T3 is 5.7"

Taking any form of T3, either natural or synthetic will suppress your TSH and fT4 so he obviously doesn't know what he is doing, and will be totally confused when he finds your TSH consistent or even lower after some time, and even more confused if your fT4 drops.


I felt a little better with 10 mcg of T3, compared with being on T4 only.... but my endo said it was a placebo with no effect. So I said ok, if it's a placebo I'm happy with that and I think you should double the dose...

so he did ;)

I no longer take it though as I'm now on NT... - my own choice and self funded.



Hi I don't think 10mg can be regarded as a placebo, as mentioned it is a powerful substance. I take 125 mg of Thyroxine and 10 mg of T3 daily and the addition of the T3 definitely makes me feel better. When I started it I just felt more 'normal'. Doc wants to reduce my T4 due to suppressed TSH so am experimenting with a reduction of 10 mg per day but reading other posts it seems T3 suppresses TSH so am a bit confused



10mcg T3 = 50mcg of thyroxine.


As per Wiki at this link it says:

"As the true hormone, the effects of T3 on target tissues are roughly four times more potent than those of T4".

T3 is very powerful and they wouldn't say it was a placebo effect if you went hyper on a small dose - they would be sprouting on about all the harmful effects when it suits them.


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