High T4 but normal T3, does this equal over med... - Thyroid UK

Thyroid UK

116,900 members135,632 posts

High T4 but normal T3, does this equal over medication?


I’ve just got my recent blood results back and my dr says my free T4 is significantly elevated and my TSH is too suppressed.

fT4 23.2 (7.7-15.1)

fT3 5.6 ( 4.3-6.8)and m

TSH 0.01.

He says this indicates overtreatment and wants to discuss my levo dose, I’m terrified. I had a terrible time the last time he reduced it and ended up with low B12 and folate. Is he right to want to reduce?

For reference my results from last August when I was feeling absolutely awful on my reduced dose were

T4 14.4

T3 4:7

TSH 0.05

14 Replies

No, you're not over-medicated, you have a conversion problem. You need all that levo (T4) in order to get enough T3 to make you well. If he reduces your levo, your T3 is going to drop, too. And, that's what makes you feel awful.

And, you can't have a TSH too low. A low TSH does not mean that you are over-medicated, it means that you now have enough hormone in your blood that the pituitary has decided you don't need TSH anymore. Thyroid Stimulating Hormone. The pituitary produces it when it finds there's not enough thyroid hormone in the blood. If there is enough, it's logical that the pituitary is not going to produce TSH anymore.

Tell your doctor that if he wants to reduce your levo, he must replace it with some T3 if he doesn't want to make you ill. And that you're only over-medicated if your FT3 is over-range. I don't know if I explained that very well, but please ask questions if I didn't. :)

Ab1J in reply to greygoose

Thanks so much, you explained that wonderfully. I doubt I will be able to convibce my Dr to give me T3 but I will try .

greygoose in reply to Ab1J

Well, GPs can't prescribe T3 anyway, under the NHS. So, you'd need to see an endo and convince him that your conversion is rubbish. I think the numbers speak for themselves, though, so maybe you won't have too much trouble. Fingers crossed! In the meantime, refuse any reduction in levo. :)

Ab1J in reply to greygoose

Thank you I will ask for an endo referral, I haven’t seen one since about 2011!

greygoose in reply to Ab1J

Chose your endo wisely. They are not all open to T3. Email Dionne at this address:


And she will send you a list of patient-approved endos. Chose one that is convenient for you, then ask for feedback, by PM, on the forum.

Good luck! :)

You would be much better off with some liothyronine. Your T4 14.4, T3 4:7, TSH 0.05 result shows your pituitary is under-preforming and this leads to your subnormal fT3. Usually TSH is a good indicator of thyroid status even when on tablets but if the pituitary isn't working properly TSH becomes useless.

Ab1J in reply to jimh111

Thanks for this info, is liothyronine T3 supplement?

jimh111 in reply to Ab1J

Yes, also called L-T3 because it is the T3 equivalent of levothyroxine (L-T4).

You have a few different routes for discussion with GP.

Previous dose gave blood results that he could live with , but not a state of function that you could live with ,

... but current dose gives extremely over range T4 that he doesn't feel comfortable prescribing , He's already had a note from your previous endo to tell him not to worry too much about your TSH being low, but he is now bothered by your fT4 level. (and probably TSH)

But ,it seems from previous 'bottom of range' T3 level on the lower dose ,that you need this much Levo in order to get enough T3 for you to feel well.

So he has 3 choices :-

1) discuss what he sees as the 'risks' of over range T4 ( + low TSH) with you, and if you understand and accept them , put a note in your records to this effect ,and continue to prescribe Levo at current dose.

( this is the 'arrangement' i currently have with my GP, somewhat against his wishes )

2) find a way to get you this level of fT3 without going so far over range with T4... to which the obvious answer is refer you to an endo for trial of T4 /T3 together, which will cost him a fortune when it comes back to him to continue the prescription, and get his head chewed off by the practice manager.

3) discuss a compromise. How much did he increase Levo by since the August result (was the previous dose 150 and currently 200 ? ). would you both be willing to try a dose somewhere between the two to get fT4 down a little and TSH up a little.

There ARE some increased risks on Levo only once TSH goes below 0.04, so it's worth considering , and it may be an easier fight than insisting absolutely on staying on the same dose.

Your fT4 is currently showing VERY over range .. if you can get him to let you trial a very slight reduction and retest in 3 months you might find that fT4 is lower anyway. maybe this was just an unfortunately timed spike in fT4 levels

( What about trying 175mcg or 187.5 mcg ? )

If you want to see the research for 'risks' below 0.04 let me know and i'll link it .

Ab1J in reply to tattybogle

I would be happy to reduce a little, but only if he will let me do it in small increments as I just don’t feel like I can go through feeling like I did last year again. I will suggest doing that for now as I’m not happy about T4 being too high either, but I am going ask him to refer me to endo and ask to be trialled on T3, I’ve been battling with this for 15 years now and the levothyroxine obviously isn’t working for me. If money is an issue for the gp could I not have a private prescription if the trial goes well, or is it mega expensive?

FancyPants54 in reply to Ab1J

It's not mega expensive to buy T3 on a private prescription in the UK. Around £1 per 20mcg tablet.

tattybogle in reply to Ab1J

I 'm out of touch with what's happening with private prescriptions for T3 at the moment. It used to be simple/affordable if you got a private T3 prescription from an Endocrinologist , to get it filled and posted from a German Pharmacy . But Brexit has very recently put a stop to that. So you'd have to ask people here what they are doing now and what the cost is, i think it's a bit of a mess at the moment.

I was just assuming you're taking 200mcg now , so ignore the 175/187.5 suggestions if not relevant . I Just meant a reduction of eg. 12.5 mcg/day might be enough to help the results , without leaving you on the floor.

I'm sure Doctors just adjust in 25's cos that's what the tablets come in and they're too busy to do the maths for any other dose. But even 25mcg is too big change for some of us.

Ab1J in reply to tattybogle

Yes I’ve been back on 200mg since just after those results last August. Recently I’ve not felt great tho so maybe that’s due to the high T4. I’ve just emailed the Dr asking for an endo referral and to say that I will reduce the levo but very gradually in the smallest increments possible. And I said I definitely will not lower it as for as 150mg .

tattybogle in reply to Ab1J

sounds like a good plan.. but be careful which Endo you get referred to , many/most are fundamentally unwilling to prescribe T3 and would be a waste of time to see.

You may also like...