Blood results on T3 only: I've had my first blood... - Thyroid UK

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Blood results on T3 only


I've had my first blood tests since changing from Thyroxine 200mcg to T3 only after seeing Dr Peatfield in October last year:

TSH 0.55 (0.3. - 4.2)

free thyroxine 1.1 (12 - 22)

T3 4.5 (3.1 - 6.8)

My GP says the TSH and T3 are fine but thyroxine is very low. Currently he prescribes 20mcg T3 as a replacement and won't let me have any more. I top this up with 25mcg of T3 which I have sourced privately. I have to say I am still feeling very tired and cold most of the time with horrible brain fog. He suggests I add some Thyroxine to my T3 but hasn't said how much. I'm very reluctant to do this as Dr Peatfield said he thought I had conversion problems and also he thinks Thyroxine is toxic for me. Not really sure what to do now - I can't afford to see Dr P again.

Any suggestions gratefully received.



15 Replies

I would go by your instinct and Dr P who has had wide experience. You may have to source your T3 but you will soon know when you get to optimum level. As you are not taking levo you T4 will be very low but it is the inactive hormone anyway. I will never take levo again.

This is a link which you may not have seen before as it gives info on T3.

greygoose in reply to shaws

An invisible link? lol

Totoro in reply to greygoose

Is it one of those links written in lemon juice and I have to heat up the screen to see it? :-P

greygoose in reply to Totoro

like :)

Hidden in reply to shaws

Link is missing hon! ;)


I would look hard for an NHS endocrinologist who will prescribe more T3. You were on 200mcg T4 and the equivalent amount of T3 is between 40mcg (using a rate of 1 - 5) to just under 70mcg (using 1 - 3).

What is the specific reason your GP won't prescribe any more than 20mcg? On my leaflet with my T3 bottle (made by Paddock Laboratories inc) it says for Mild Hypothyroidism:

"Recommended starting dosage is 25mcg daily. Daily dosage then may be increased by up to 25mcg every 1 or 2 weeks. Usual maintenance dose is 25mcg to 75mcg daily".

I had a quick look to find this online and I found the information that goes with "Truven Health Micromedex products liothyronine". which says the same thing.

Would your GP take any notice of this information?

Thanks for the responses.

Totoro - my GP didn't want to prescribe T3 because of cost - he admitted this to me candidly and soon after I began taking T3 both he and I received a letter from the PCT advising that T3 should not be routinely prescribed and that there was only anecdotal evidence of its efficacy. Eventually, the NHS Endo reluctantly agreed to let me have a trial because he didn't want to see me again (can't think why!) and so my GP prescribed 20mcg T3 which he said was equivalent to the Thyroxine dose I was taking. He seems pretty uninterested in the hypo symptoms I now have other than to tell me he's not surprised given the T4 levels I have at the moment. Basically, I'm on my own with this I fear.

Dr P advised me to build the T3 dosage gradually until I was taking 45mcg which is where I am at the moment. I still feel unwell on this dose. Perhaps I should continue to increase T3 until I feel better?

It would be very useful to have the link you refer to Shaws.

Thanks again

yes you are right, what you are meant to do is UP the T3, NOT add T4, Dr P told you he thinks you have a conversion problem so why add T4?

your GP knows NOTHING about T3, first of all bloods when you are on T3 only are useless they do not tell you how you are. second fT4 will ALWAYS ALWAYS be low when on T3 only and when you are on enough T3 to feel well it will probably be zero, mine has been zero for a long time :)

also you will end up getting a suppressed TSH so get ready for the GP telling you you will get a heart attack and your bones will crumble (sigh)

ps I've been on T3 only for a year now

Thanks for your input. Can I ask what dose you are on to feel well? I know we're all different and what suits one won't suit another, but I wonder what is considered a 'maximum' dose for T3 - I suppose what I'm saying is that I'm worried about tipping myself into hyper symptoms and also, as I have acute inflammation in my joints (arthritis etc) I don't want to exacerbate that.

HI, I"m on 160mcg daily but will increase soon. I know a woman who is on 325mcg T3 only daily so there is NO maximum, there is only what makes you well :)

I agree that you need to take more T3. When taking T3 it is usual for TSH to be supressed - mine is < 0.02 and my endo is happy with this. I am not surprised that you have hypo symptoms when your TSH is this high :D I would follow Dr Ps advice and increase your T3 until (hopefully) your hypo symptoms disappear. xx

Hello,as your Dr has agreed to prescribe you think he would write a private prescription for it ?as my GP now has to do.l say this as l now fax my prescription to Belguim And pay 6. Euros a packet.PM me for the details if Gp is unable to print the name of the tablets (Cynomel) on his computer so did hand write a NHS prescription ,but when l went for a repeat he was unable to write a new one.he doesn't charge me for writing a private prescription .x

Hi Donna

I don't have a problem obtaining extra T3 - I get it on line as per Dr Peatfield's recommendations so I can increase the dose without running out of the tablets and I have done so today, taking my dose up to 50mcg daily and will see how that makes me feel over the next couple of weeks. Dr P had no preference about what time of day to take the meds so, at the moment, I split them - half in the morning on an empty stomach as soon as I wake up, and the other half just before I go to bed, about 3 hours after dinner. Is this the best way to take them?

Would offering to pay a prescription fee, for t 3 make any difference. I'm thinking of doing this on my next oppointment with the doctor next month.

Yana - As I said, I source my T3 on line. The reason my GP prefers to prescribe Thyroxine is that it's much cheaper than T3 - he originally gave me a private prescription at my insistence and I discovered it would cost £80 for 28 T3 tablets from Lloyds chemist! Now I am prescribed T3 on an NHS prescription but he is only willing to let me have 28 x 20mcg tablets per month and has suggested I add some thyroxine to this dose as I am still having hypo symptoms - he won't prescribe a higher dose of T3 even privately so I think there's some residual nervousness around T3 in general.

Every GP is different - some won't even consider prescribing T3 and some are much more open-minded. I think you first have to demonstrate that Thyroxine isn't working and that can be difficult given that they tend to rely mostly on blood tests.

Good luck with your GP.

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