When should I take my last dose of T3 before a blood test please? I am of the opinion it is the night before but if someone could give me the correct advice please. My NHS end wants me to take my T3 two hours before my blood test and I feel that this would just be testing the T3 I would have just taken.
It is a battle - I am trying to get T3 on NHS.
Many thanks
Letty222
Advice here is to split your dose of T3 the day before the test into 2 or 3 and take the last dose 8-12 hours before the blood draw .
T3 peaks in the blood 2-4 hours after ingestion so testing then gives this peak level which is a "false high" and may mean that your endo reduces your dose or, worse still, removes your T3 altogether .
Thank you Seaside Susie. My endo hasn't a clue. He has specifically asked the dr to ensure that I have my T3 two hours before blood draw. I have been self managing for years and only saw an end last year to try and get it testing and treatment on the NHS. I need proper testing and he said he would prescribe T3 but he's just playing around. He wants me to have a TSH "more appropriate to my age" and hasn't a clue about mono therapy pushing T4 which I do not want as I don't convert well. I am so tempted to give up but I would like T3 on prescription rather than self sourced. I am waiting for a call from my dr, who I have never met since moving to new area last June, but fear he is clueless to if he is pushing this line.
don't be fooled into thinking a specific request for a 2hour test is because they are 'clueless' ,, they know EXACTLY what they are doing when they insist on a test 2 hours after taking the tablet... they want to catch that peak when it is at it's absolute highest .
Their motives for wanting to see that peak and not the mid point are what you need to to be looking at .
I hear you Tattybogle. I just hoped for better. I’ve told the surgery I won’t take the test under those circumstances and look forward to the GP calling me trying to convince me otherwise. They haven’t offered any other relevant tests either,
Letty222 Hi there, like tattybogle says asking for a test two hours after your dose is intended to catch the peak free T3 in your blood. I'm on T3 only and my NHS endo usually asks me to to test T3, T4 and TSH first thing in the morning before taking my first dose - well away from the peak.
Thank you Hashiboy. Yes, well away from peak is what I thought was the way to go too. This endo is horrid but little joy on NHS so not sure how or whether to proceed. Thanks for answer.
Letty222 Sorry you are not getting good support from your endo. Any chance b you can find a more supportive one from the Thyroid UK list? I'm lucky to have a supportive GP so never feel I have to worry that a test result will be used to give me less medication than I need. I really feel for people who have the stress of that worry on top of just trying to feel well. Good luck .
A lot depends on your dose and whether your problem is glandular or cellular!
I'm on high dose T3-only and no longer have blood tests...on high dose T3 the only way to monitor the level is by signs and symptoms.
Blood tests were not designed for T3- only treatment
But any test should be 12 hours after the last dose
Your endo is setting you up to fail....or hasn't a clue!
After 2 hours your serum level FT3 will be peaking and the high reading will be their excuse to withdraw T3.
I self medicate so don't have to follow ill informed/ unhelpful advice from medics.... but accept that's not an option for everyone.
You're correct if your gut feeling is that something is wrong...listen.
Request an explanation....your best interests are supposed to be their focus....so they need to put your mind at rest!
This might offer some background info.
thyroidpatients.ca/2019/08/...
paulrobinsonthyroid.com/why...
Thank you DippyDamrme, your message resonated fully with me as I too self medicate but thought I’d venture to try and get NHS treatment. I agree endo setting me up for a fall. Thanks for links, I will look into it some more and do my own testing as well. I go by temperature and symptoms as I am hashi as well ad hypo. Following advice on here I am gluten free now and trying with dairy free etc. Thanks again for taking time to reply.
Going T3-only can be a tough and lonely journey because the powers that be neither understand nor support the protocol....and I'm convinced T3 terrifies them because they expect us to drop dead and then they will have to explain that to the " top brass" with the fear of losing their registration.
Were it not for this forum when I started on T3 I would have concluded it was just me...but no....and that kept me searching for ( and finding) the answers that medics over decades could not offer
Fortunately my GP is open minded but it did take a little time and a letter of explanation regarding the whys and wherefors of my decision....and a statement saying that I take full responsibility for my use of T3. She now leaves me to it.
I'm aged 77 and goodness knows what will happen if I end up in hospital ,or in care....no T3 I guess, with obvious consequences. So, I need to keep my wits about me....and T3 ensures that.
It is complete and utter madness and I doubt that any other life threatening disease is so badly treated, but my decision, made after a great deal of research, was about my life not about boosting NHS opinion.
My brief encounter with an endo was a disaster so I quietly left and resolved never to return! I would much rather have the safety net of the NHS....but hey ho!!
I'm sure there must be clued up endos out there but they seem as rare as hen's teeth!
It sounds as if you are knowledgeable and managing your condition well...in your shoes I'd be thinking, " Do I want to upset the apple cart"!!
Good luck I hope you are one of the lucky ones ....and apologies for the rant!!
If you are still on the 75 mcg even 18-24 hours might be appropriate to have a blood test within range. I am on 30 and still within upper quarter of the range after 18 hours. Depends on your metabolism and the dose. I would take the test, but as many of us do, leave the gap you know should be sufficient to ensure the result you want, not they. Ideally you first might test privatelly with a gap you want to use and then use the info for any 'official' testing.
Blood testing when on T3 only
T3 trial and testing 
Help finding T3 doctor
NHS T3 Blood Testing.
starting T3
