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Thyroid UK
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Sourcing 5mcg Liothyronine (T3)

Hi all,

I'm relatively new on here and have just been tested and received confirmation of having the DI02 polymorphism from 1 parent. So, in summary I am converting some T4 to T3 but in all probability will never feel fully well unless I supplement with some additional T3.

I've been to see a private endo who has agreed that a trial of T3 is worth trying, however due to BMA restrictions he can only prescribe T3 at the 'natural T4:T3 ratio of 14:1 and only then if this does not leave me "over suppressed" on TSH (i.e. Outside of the 0.3 lower range they stipulate). I picked up the undertone that this wouldn't be his preference but that if if he doesn't adhere to this he will find himself in hot water.

This means that based on my current meds of 125mcg Thyroxine he can only suggest adding in 5mcg T3 and dropping to 75mcg and seeing how I get on. He said we'll re-test in 6 weeks and if I then feel undertreated and my TSH is not oversupressed he can then justify adding more Thyroxine back in.

So, armed with my shiny private prescription I've called a few pharmacies this morning onlyby discover that 5mcg is a special item and that for the 50 days he's prescribed that will be £292 please!!!!!

So, two steps forward and one step back and I'm fairly certain that the GP who is covering maternity for my lovely normal GP is not going to prescribe me T3 on the NHS (our last conversation ended in him suggesting it might be time for me to consider whether I have a mental health issue causing my ongoing symptoms)

If anyone can pm me with any suggestions of where I might be able to order T3 online (preferably 5mcg but if not 10 and I can cut in half) I would be really grateful.

Alternatively any other ideas/solutions gratefully accepted!

My last labs:

TSH 0.22

FT4 19.6

FT3 3.1

5 Replies

I've been to see a private endo who has agreed that a trial of T3 is worth trying, however due to BMA restrictions he can only prescribe T3 at the 'natural T4:T3 ratio of 14:1

I'd be interested in seeing the proof of that. The BMA doesn't set guidelines or regulate doctors in any way, it is a trade union for doctors. You've been fobbed off.

It is possible to buy 5mcg tablets of T3 but they are phenomenally expensive. It would be far cheaper to buy standard T3 tablets in 20mcg or 25mcg tablets and cut them into quarters with a scalpel.


This means that based on my current meds of 125mcg Thyroxine he can only suggest adding in 5mcg T3 and dropping to 75mcg

Another bit of nonsense. 5mcg T3 will NOT replace 50mcg Levothyroxine. Most patients find that T3 is about 3 or 4 times as potent as Levo. (Personally, I would say 3 times.)

So your endo is going to massively under-medicate you to "prove" the point that T3 doesn't work, and then he'll put you back on Levo.

This endo you are seeing is either a deceitful liar or completely incompetent.


A normal thyroid makes t3 and then you do the conversion thing, to end up with about 25 mcg a day...... So the 5 mcg is no where near what you will need.....

Plus buying in 5 mcg tablets is stupidly expensive....

Sort yourself out some 25 mcg tablets and cut them up into halves or quarters.....

Trying to medicate with t3 and not get a suppressed tsh is impossible. What does he think will happen with a low tsh? Ask to see the evidence...

Though tbh i wouldnt go back.....



Your T3 is, at present, at the bottom of the range when on levothyroxine so if you have a polymorphism the additon of such a small T3 wont do much.

Also a 14:1 is ridiculous. They are so far behind in their studies/knowledge.


This is a study done on the equivalence of T4/T3 combination. Go to page No. 80 (which also shows as page 6 of 12 at the top of our extract) and the first paragraph. Excerpt - I have emboldened the section:

Dose Selection in T3/T4 Study RCTs

The second logical basis for a conclusion

is the actions taken, i.e., the doses given to the


Most subjects received T3 below its

adult starting dose of 25 mcg/day.

The subjects in RCTs received T3 in some ratio to the

withdrawn T4.

The various RCTs used T4:T3

ratios of 14:1, 10:1, and 5:1.

Subsequent research by the US National Institutes of Health

(NIH) found the therapeutic equivalence was 3:1.Ho

41 Thus, most of the subjects were under

treated with the T3/T4 combination. In light

of the NIH finding, the conclusion that T3

therapy is never needed is invalid.


I'd copy and highlight the appropriate section.

1 like

Thanks everyone for all the support and advice, it really is very much appreciated as it feels like a minefield out there!

I'm not an unintelligent person but biology was never my forte and I really would have preferred to do this under the eye of a specialist. However, I totally agree - my gut instinct when I came out was a concern with this approach that I will never get to a decent dose since I'm already "over suppressed". That added to the astronomical cost makes me think the universe is trying to tell me something...

So reading your responses, if I chose to go my own way and replace some of my T4 by self medicating at a 3:1 ratio I might consider maybe replacing 75mcg of T4 with 25mcg T3?

However... if I was converting properly I suspect I might not need this level of T4 in the first place so do I actually need to fully replace the T4 with T3 or is that likely to push me over the edge into hyper symptoms ?

Is a slowly slowly approach of cutting the pills and adding it in a bit at a time better to start with? Any suggestions as to where I might start?

Sorry for all the rapid fire questions but I'm having a not so brain fogged day so need to take full advantage! 😃


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