How do I test when taking NDT?: I switched to NDT... - Thyroid UK

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How do I test when taking NDT?

FancyPants54 profile image
38 Replies

I switched to NDT in early December. I need to do a test now because I am so tired I can barely function but I can't sleep either.

I have my kit. How should I take the meds the day before? I was testing 12hrs after my last T3 and 24hrs after my last T4 when I was using combo.

Now I take 1 grain Armour at 07:30 and 3/4 grain at 13:30.

Can someone advise a sensible strategy so that I find out what's gone wrong with it please.

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SeasideSusie profile image
SeasideSusieRemembering

Treat NDT the same as T3 when testing. Split dose the day before, last dose 8-12 hours before the blood draw .

Beau55 profile image
Beau55 in reply to SeasideSusie

Hi Seaside Suzie, please may I ask what the science is behind only leaving 8-12 hours as I’m not familiar with this?

In order for me to do this I would have to take my second dose at 9pm to leave 12 hours before 9am blood draw which isn’t making any sense in my head. I know that the T3 peaks but surely it’s best to measure when taking doses on their normal schedule?

I feel NDT is largely best dosed on symptoms and signs over bloods which were designed for synthetics so leaving only 8 hours muddies things further but would love to know more if possible 😊

SeasideSusie profile image
SeasideSusieRemembering in reply to Beau55

Lots of posts on the forum about this, on an almost daily basis. T3, in whatever form, has a half life of 24 hours. T3 peaks in the blood 2-4 hours after ingestion. Testing too close to a dose gives a false high FT3, too far away gives a false low FT3 result so it makes sense to test roughly half way between doses to get a measure of the normal circulating amount of hormone without any peaks or troughs to avoid a doctor adjusting dose based on an incorrect level.

Beau55 profile image
Beau55 in reply to SeasideSusie

yes I understand I’ve seen it a few times on here but never checked with anyone why/only just occurred to me to check. I just thought I would check to see if you had any research papers that maybe I hadn’t come across.

I just felt like it could potentially give a false high/prevent a dose increase when most of the time it’s easier to dose NDT to symptoms / signs. There is so much reliance on bloods these days and getting an ‘accurate’ idea of cellular T3 concentrations is hard enough when trying to gauge dose response on tests designed for synthetics.

FancyPants54 profile image
FancyPants54 in reply to Beau55

Some of us need to submit bloods to a doctor to get a repeat prescription. Although it's a private prescription, that's the position I'm in right now. I need a blood result that gives me a clue if I need to raise or lower my dose because I'm new to NDT and feel, frankly, terrible right now and have no real idea if I'm over or under because my symptoms of both are always the same. And at the same time I need a blood result that will ensure I get a repeat prescription so that I can continue to buy my NDT from a private UK source. I don't fancy trying to import it right now.

Delgor profile image
Delgor in reply to FancyPants54

radd Looks like there are differing opinions on this which doesn't help matters - it's the same as when I put up a post asking why some endos tested patients 4-5 hours after they had eaten and taken meds which obviously shows peak levels and we don't have peak levels in our blood all day so surely shouldn't be prescribed on this basis. Both when on 3 grains and now 1 1/2 grains my T3 level was 8 doing it this way! As Beau55 has said NDT should be taken until the relief of symptoms but a lot of endos don't know this. Hopefully radd can add her views to the mix as for years I was well on 3 grains of NDT and now poorly on 1 1/2 grains.

FancyPants54 profile image
FancyPants54 in reply to Delgor

Why are you on half the dose that made you feel well? Was that an end's doing? I'm sorry that happened.

I've just been reading the thread about the FDA and NDT and wondering what on earth I'm doing trying to get onto NDT in the first place as it looks like it's going to get more expensive and difficult to get hold of than it already is!

Delgor profile image
Delgor in reply to FancyPants54

Yes you are right in that some NDT will become more expensive which isn't good news to those who have always felt well on it especially if we have to factor in seeing a private endo in order to get a prescription. Unfortunately I was never told to split my medication before a test and just left 24 hours in between which I now know from this wonderful forum would have been giving me falsely low results for years - oh dear! The private endo I saw by zoom about 18 months ago wanted me to lower my dose still further to 1 1/4 grains based purely on the result taken after 4-5 hrs of taking meds and eating which I didn't think was right and glad I didn't do it.

Based on my last MMH test and taking meds 12 hours before the blood draw I seem to have some wiggle room for raising T3 still further so I've upped NDT by 1/4 grain this week and will retest in 6-8 weeks.

FancyPants54 profile image
FancyPants54 in reply to Delgor

I hope it works for you. Fingers crossed.

FancyPants54 profile image
FancyPants54 in reply to Delgor

I am currently mid-way through my day of alteration prior to tomorrow's test.

I decided to split my dose into 3 today because I thought I'd be really tired if I only took meds 12 hours apart. So I split my 1 and 3/4 grains into 3/4 x 3/4 x 1/2. I'm due my second dose now and will take the third dose 12 hours before the test. That's what I was doing when using T3.

As it is, I've just taken my temperature before the second dose and found it to be 36.8, which is much better than it has been when starting the day with 1 grain!

Delgor profile image
Delgor in reply to FancyPants54

That sounds good to me as we are all different and maybe you've found a way that suits your body better. As so many people say it's all trial and error when trying out thyroid meds - I have learnt so much from this forum and still keep learning even though I've read umpteen books. Hope test goes well for you!🤗

FancyPants54 profile image
FancyPants54 in reply to Delgor

I hope it gives me a steer, I need to now which way to go.

Delgor profile image
Delgor in reply to FancyPants54

I'm sure everyone will be routing for you and do let us know how it all goes👍

radd profile image
radd in reply to Delgor

Delgor,

My thoughts are .....

Many members are testing to maintain or increase their Levo prescription with GP’s beholden to the TSH. Therefore, SeasideSusie’s advise is by far and away the best as will offer the lowest TSH and an average reading of thyroid hormones levels. Even if you have to switch your previous days dose about to comply with the timings, you will still have plenty of T4 and some T3 in your system and this is what is being tested. However, if you are testing for yourself, then you can test anytime.

Deliberately testing soon after taking meds is done to measure the highs that can be damaging long or short term for some people. High T3 levels can cause both osteoporosis and cardiac conditions (note this is nothing to do with a suppressed TSH which is just a consequence of elevated thyroid hormone but the actual T3 hormone itself). It can also cause conditions like high SHBG and low free testosterone, and impair good T4-T3 conversion by raising levels of inactive metabolites. I used to test 2 hours post meds for my endo because in my early days of medicating, thyroid hormone meds gave me three days of psychosis and I’m always mindful never to take T3 too high.

The important thing is to always test like for like.

I don’t agree with taking NDT until the relief of symptoms because symptoms may be from another cause, making it easy to miss your sweet spot. And once you have over-range thyroid hormone when do you stop if symptoms don't abate. For example, iron and nutrients may not be optimal or you may be carrying chronic (low grade) inflammation (excess weight or swellings, aches, pains) that is negatively influencing the deiodinase enzymic behaviours. Therefore, by taking more and more thyroid hormone you risk ramping up these negative behaviours and making yourself further symptomatic. 

There are people who experience genetic differences that result in thyroid hormone resistance and necessitates high thyroid hormone levels but for the rest of us I would also look for the cause of why the thyroid hormones aren't working rather than just keep taking more.

Delgor profile image
Delgor in reply to radd

Thank you so much Radd for such a detailed reply. Hmm - that's certainly given me a lot to think about and hopefully it will help others too. Looks like I probably was overmedicating for years by not knowing the proper testing protocol but there's no use crying over spilt milk now as I had a good quality of life when it was most important to me and perhaps sometimes choices have to be made. Thank you again!

FancyPants54 profile image
FancyPants54 in reply to Delgor

Surely, if you had a good quality of life and felt well, you weren't overmedicated? I've read what Radd said and I don't think she meant you should not feel well in the process. The reference ranges might not even be right for your own body's set point.

Delgor profile image
Delgor in reply to FancyPants54

Well I clearly was overmedicating (not that I knew it) as I had never been told the correct protocol for testing and always felt well with having a high T3 and a TSH of 0.01 but they would have always been falsely low results - eek! I was told years ago that I had CFS but amazingly NDT gave me my life back again and I've been told yet again that I have CFS but I won't believe it until I've ruled out all other possibilities. Obviously lots to learn still and to test for but I'm not quite ready for my box yet so I'm up for the challenge - fingers crossed for you for tomorrow😉

FancyPants54 profile image
FancyPants54 in reply to Delgor

Thank you.

Havoc83 profile image
Havoc83 in reply to FancyPants54

Poor you, I am feeling exactly the same so I sympathise.

Have you done a cortisol test?

I increased my T3 several times (against endos advice) because I can barely function, sometimes even have to crawl upstairs as my legs are so weak… But according to my bloods, I should be fine.

A saliva test has come back showing I am well under normal levels of cortisol throughout the day. Someone more experienced may correct me, but I understand that this can result in an inability to get to sleep and being wide awake in the evening despite being exhausted. (Spot on for me) And crucially, we need cortisol for thyroid hormones to get into the cells in our bodies, so it can mean that although you have plenty of thyroid hormones circulating in the blood, they can’t get to where they are needed. I’m currently waiting to see a doctor to see what I need to do to sort this out. Good luck x

FancyPants54 profile image
FancyPants54 in reply to Havoc83

I have tested cortisol in 3 ways. The saliva test failed due to lack of saliva! But the other 2, a dexamethasone test to rule out Cushings and a 24hr Urine collection test to rule out Addisons were good.

Delgor profile image
Delgor

Hi FancyPants

Sorry things still aren't good for you! You can just take your morning dose as per usual the day before the test but then take your second dose 8-12 hours before doing the test the next day. After the test you can then take your usual morning dose and go back to the pattern that suits you. Take Care!

FancyPants54 profile image
FancyPants54 in reply to Delgor

oh god that’s going to be a looong day! Thanks.

Delgor profile image
Delgor in reply to FancyPants54

You'll be fine🤗

FancyPants54 profile image
FancyPants54 in reply to Delgor

I don't have the energy to move much before the second dose at the moment. And I absolutely have to go into work tomorrow and pack orders so it will be hard. Plus mum will need to have her shower tomorrow morning before I go as she's having her hair done the next day. You wouldn't think showering and old lady would be exhausting, but when you are exhausted to start with, it is knackering.

Delgor profile image
Delgor in reply to FancyPants54

Oh I'm sorry - it's hard enough feeling exhausted without having other pressures upon you. I obviously can't help but I do sincerely empathise and really hope that NDT does it for you!

FancyPants54 profile image
FancyPants54 in reply to Delgor

So do I because I'm feeling a bit at the end of my tether right now. Mum is quite demanding and at 88 it won't get any easier. I tell her endlessly that I have very limited energy but it never stops her asking for me to do many things. For the next 2 weekends she has visitors coming. For which I will have to shop for afternoon tea foods, be on hand to make the tea and serve, wash up, sweep the floor before they arrive etc. There's another visitor lurking wanting to come soon too. Mum hasn't been in her new home long. We had it built in our garden last year so that I could help her more easily. But actually it might be easier, as in my front door is only a few yards from hers, but the demands have really gone up a lot. I have never felt this tired or done in in my 9 year journey as I have since I switched to Armour.

Delgor profile image
Delgor in reply to FancyPants54

It's really hard to know what to say to you that can be of help since you've already tried combo etc. but Armour certainly isn't for everyone - I actually felt a lot better on Nature Thyroid until it was withdrawn from sale. However, you certainly sound as if you've taken on more than you envisaged with trying to be a wonderful daughter when you clearly aren't feeling good yourself - even when I felt relatively well I found it very hard looking after my Mum for long spells as she had dementia which was very hard to deal with at times. Somehow or other you need to change things or else you could end up resenting her which would be so sad for you both and as you have already said things aren't going to get better so it needs to be tackled sooner rather than later. Hope it helps a little. xx

Beau55 profile image
Beau55 in reply to FancyPants54

fancy pants do you have the resources to be able to dose the NDT until you feel well? I would do bloods and then try to keep raising until you feel better. 1.5 grains is still very low and hence why you feel garbage, especially if caring for your mother. Also, Have you checked out any cortisol issues? X

FancyPants54 profile image
FancyPants54 in reply to Beau55

I do have enough to increase a couple of times at the moment. But I’m cautious because for me symptoms of too much are always the same as symptoms of not enough. I’ve learned that the hard way. I must avoid over medication at all costs because diodinase enzymes kick in very quickly with me and convert my hormone into inert metabolites for excretion very easily.

I suspect I am too low. But I need to see that before I push an increase. I was on 2 grains from early December until mid January and feeling much better than I do now. But I caught a cold from hell and it has screwed everything up for me. Terrible nighttime anxiety attacks out of nowhere meant I reduced my dose. I’m hoping whatever caused that has now moved out of my system.

PixieElv profile image
PixieElv

are you able to test in the evening? Then you could take your dose during the day and test when you are home.

I hope it works out ok for you and best wishes

BB001 profile image
BB001

See graph. This is why I test fT3 after 12-15 hours. I want the peak hill of the last T3 dose to be over, and I want to test at the beginning of the tail, which shows my underlying levels. To be honest, the most important things are:

1) consistency between tests i.e. test at the same time of day, at the same number of hours after your last dose

2) test 12+ hours after last dose.

This way tests will be comparable between each other.

There is a #3 which is

3) adjust the number of hours after your last dose (within reason), that will mean your doctor doesn't freak out 😆

This infographic is from thyroidpatients.ca.

Graph of T3/NDT half life. It looks like a whale facing left. Test at start of tail.
BB001 profile image
BB001

When I was on bovine desiccated thyroid (Thyro-Gold) I used to take my last dose at 4-5pm, then test early next morning.

I think the main thing is to use your first test after being on NDT as a baseline. This means: do the test, note your symptoms, and the number of hours after your last dose you took the test, and time of test.

This is then your baseline against which all other tests can be measured.

You can also use this baseline test to see what fT3 and fT4 levels your current dose yields.

Edit: make sure subsequent tests are under the same conditions as the baseline test, i.e. take the test at the same time and the same number of hours after your last dose. Remember to note the dose and symptoms for subsequent tests.

HodorO-H profile image
HodorO-H

I’m sorry you’re feeling so awful.

I’ve been on NDT (ERFA Thyroid) since July 2021. It’s taken time to get to to the right amount with small quarter grain increases, and decreases! I’m now settled on 2.45 grains, which is a lot higher than I expected, but NDT I’ve found out, is al about how you feel rather than tests.

This said, I still test regularly. I take my ERFA at similar times to you (split at 0700 and 1500). I always take my blood BEFORE my first dose of ERFA in the morning. If this means waiting to take it due to a later GP appointment, I do. I have a mix of private tests (take my blood when I wake up) and GP (once a year).

I hope this helps. And I hope you feel better soon.

FancyPants54 profile image
FancyPants54 in reply to HodorO-H

Thank you. It's good to know how others do it.

Valeriu profile image
Valeriu

When I was testing I was told to make sure it's 15 -18 hours after your last NDT and that's how I've always done it; Of course note what dose you were on when you took the test; I think you need to be on same dose for 6-8 weeks before you test. Good LUck

serenfach profile image
serenfach

I feel for you. Two things - do the test, it sounds like you need to go up a smidge. I find I have to in the winter, although I am much busier in the spring (lambing) and summer (hay). Come back with the results and we can help further.

The second thing is your Mum. Is there any help available through the Council - just a couple of days a week to do the bathing etc? This would do two things - give you a break and show your Mum that helping her is Work! She may hate the idea of someone strange coming in, but it would show her that you are struggling, and need help.

Good luck - I take NDT and am much better on it than I was on T4 and T3, but it can take a while to get the dose right (and then it moves!) Sending a hug.

FancyPants54 profile image
FancyPants54 in reply to serenfach

Lambing must be kicking in big time for you now. I live in a very small village with a farm opposite. I love being out here. My Nan was a farmer.

We've only just moved mum out here. She was independent in her own home in a city but I could not easily get to help her. So we converted a small stone barn in our garden into a lovely little 1 bed, open plan living/kitchen home for her with her own front door. I have cleaners coming in for her once a fortnight. That works well. But since she came it's as if she's just handed over responsibility for much of her life to me. She didn't ask. Just presented me with it. Fortunately she only wants a shower once a week. That's enough for someone who sits down most of the time. But when I feel like I feel this week, it's still a huge effort. Getting carers out here is not easy. And right now I don't want to do that. I want to get well so that I can do it. It was the plan. But so far I feel a lot worse on NDT than I did on combo and I don't understand why. This test will, hopefully, point me in the right direction.

Rabat1923 profile image
Rabat1923

hi…just make sure you don’t take meds before blood test,.

If you take armour in morning and later…just fit in….take blood mornjng. Susan.

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