When to stop taking Armour before a thyroid blood test ?

[Montheone]

I’m on 2.5 grains of Armour in the morning - having a thyroid blood test on Monday morning - should I stop Armour Sunday morning or just Monday morning ?

[waveylines]

I take Armour too first thing in the morning The specialists I saw including an endocrinologist all recommended that on the morning of the blood draw that I take my meds AFTER the blood test. You need it taken as early as possible, fasting, My GP cant test till mid morning so I go to phlebetomy up at the hospital -theyre open from 7am. Hope this helps.

[Montheone in reply to waveylines]

Thank you 👍🏼

[SeasideSusie Remembering]

Montheone

General consensus here is that when on NDT or T3 then the day before the test the dose is split into 2 or 3 (whichever your dose easily allows) and you take the last dose 8-12 hours before the test. This avoids a false high or false low FT3 level. Taking too close to the test gives a false high as T3 peaks in the blood 2-4 hours after ingestion, and taking any longer than 12 hours gives a false low.

[waveylines in reply to SeasideSusie]

Hello Sea-side Suzie,Please can you send me the research to back your approach to testing ndt? I cant find any but clearly you must have some as you state its by "general consensus here."

As Ive said three qualified medical doctors, two emminent endocrinologist all recommended the standard 24hrs before testing . If you take it in two or three doses you will be falsely raising the ft4 level as well as the ft3 level. So the ft4 will be higher than under normal testing. Look forward to reading the researched science on your approach. Many Thanks.

[tattybogle in reply to waveylines]

I think it would be fair to say that the 'general consensus' comes about mainly as a way to deal with those Endo's who (unlike yours) , will insist the last dose of T3 containing meds must be taken much closer to their test ... e.g there are folk on here whose endo insists on '4hrs before ' .... thus giving the rather false impression of higher T3/4 levels than they actually have for most of the time.. due to test including the peak that happens a few hrs after ingestion.... and so risking an inappropriate dose reduction if the endo doesn't acknowledge that this peak is short lived and probably harmless. Finding an endo that says "24hrs" is quite handy for you , and i agree with your logic .. if you normally take your T3 containing meds in one daily dose in the morning , and your endo say's 24hrs .. then personally i'd do 24hrs.

*edit, but take into account when interpreting your fT3 result , it will be the lowest point you usually have and that for much of the day your fT3 level will be a bit higher than your result shows.

[waveylines in reply to tattybogle]

Thanks Tattyboogle. Personally I'm not keen on generalisations when recommendations are given. This is a combination medicine so if u test as described by Sea side Suzie then you will invalidate the ft4 result. The ft3 result will be a bit of an unknown because it doesn't allow for the additional extra t4 and the conversion that may or may not happen & youve added extra T3 in Also I dont believe the test was designed to be used like this? . Thats why I asked for scientific research to back this approach. Isabella WENZ recommends that all T4/T3 combination meds should be tested after 24hrs. Unfortunately my phone crashed and I now can't find the link as was going to add it to this!!! Grrr. Sorry!

So to get to the bottom of all this it would be helpful to have the scientific research behind it.

Even Paul Robinson talks about the issues around testing Ft3 and the problems that surround it when using that test as a guide to treat for T3 only. I really don't think you can measure it as accurately as ft4 which is slower to change. Ft3 is prone to spikes as a consequence of the med but in addition the circadian rhythm also has impact on it (if I read correctly) 😊 so you may test at a high or low point but how will you know?

I'm not a scientist or a medic but would dearly love someone who is to follow this up as am interested. Till then will continue the advice that three different experienced specialists (well thought of in our community) recommended for ndt - test after 24hrs then take meds.

[tattybogle in reply to waveylines]

if u test as described by Sea side Suzie then you will invalidate the ft4 result. . how ?The total dose of T4 is still the same over the previous day , you haven't increased the total dose , and test is still far enough away from the last dose to avoid the peak after ingestion, ... and a large part of the fT4 level is made up of the accumulated dose from the previous few days.. so taking the previous days total T4 amount in 1 dose 24hrs before , or split into 2 with last one 12 hrs before isn't going to make much difference at all to the fT4 result on test day.

I dont believe the test was designed to be used like this? ... It wasn't designed to be used in any particular way. it's just a test . it measures what's there at a given point in time. The correct use of a test ,and the correct interpretation of the results received is dependent on an understanding of the effect of time of last dose etc on the result you get . There isn't a right or wrong way to use the test.

If you want to see the highest point fT3 ever gets to in the day , then you test during the peak. *shorty after taking the T3 .

If you want to see the absolute lowest then you test after 24hrs (assuming you normal take your NDT once a day)

If you want to see a reasonable estimate of the average level you test after 12hrs.

If you want a proper comparison with the previous test , you make sure the time of last dose/ time of day of test is consistent with the previous test.

There isn't research or (even 'agreement' amongst the endocrinology profession) to back up the 'right' way to use the test , because there isn't a 'right' way to test ... the choice of timing of last dose depends entirely on what the person testing is looking for .

Or have i misunderstood your point ?.. i have just had a glass of cider so that's quite possible.

[Montheone in reply to tattybogle]

Ok interesting comments everyone ! I’ve taken 2 grains of NDT about 1.30pm before test at 9.15am tomorrow - will Post results

[waveylines in reply to Montheone]

Sorry Montheone....not my intention to hijack your thread....just a difference of time lag for testing does apply for you too. Apologies. Hope you get the results quickly.

[waveylines in reply to tattybogle]

😊 The ft4 test ranges are based on after 24hrs of no medication. In Sea side Sussies approach because its a ndt you will be taking t4 up till 12hrs before the test. Thats half the time recommended. Therefore the ft4 ranges set for the test won't be correct....you will have a higher level of ft4. If this wasn't the case you wouldn't need to stop levothyroxine for 24hrs before testing. Hope that makes sense despite the cider! 😊 Also you wont know the impact of the extra t4 on thyroid conversion to T3 taken closer to the test. I tried to find research on this as I thought maybe new research had come to.light on testing ndt. I cant find any. All I can find is 24hrs gap like for levothyroxine that I was told to do and have been doing for 15yrs. 3 different professionals at different stages of those 15yrs all said the same to me. I cant say their names but top of their game & highly thought of by patient forums. Sadly one passed away, the other two have retired now.

[tattybogle in reply to waveylines]

The ft4 test ranges are based on after 24hrs of no medication.

not so .....fT4 ranges are "95% population reference ranges" and are derived from 'healthy' individuals (with no known thyroid disease, and therefore not on any thyroid medication) The top 2.5% and the bottom 2.5% of these results are then removed to leave the "95% population reference range" .

(Then some complicated indecipherable stuff happens, which means all the manufactures of different immunoassay test platforms are calibrated to totally different ranges to each other ie. one is [12-22] ish while one is [8 -14] ish .. and then once the platform is purchased by a lab , they may (or may not) apply a slight local adjustment to the 'factory' setting .. the local adjustment might be something like 100 or so people who work at the lab, or are local patients who's (non thyroid disease ) results go through the lab. .. so the 8-14 might become eg [7.9 -14.3] )

So whoever gave you the impression that fT4 ranges are 'based on 24 hrs of no meds' was not helpful to your understanding of how the fT4 test result is to be interpreted.

however ,,, due to the cider ... i confess to only reading the first half of your reply,... a bit to fast, and a bit blurry

[waveylines in reply to tattybogle]

I didnt mean that Tattyboogle - think you've misunderstood...am aware of how they were set. What I meant that is the standard way of assessing ft4 levels. What makes this way better? Is there evidential research to show this is better for thyroid treatment? Whats the reference for it? It may well be better but need more information that shows that.

I think best to start a new post for this discussion ....

Am so sorry Montheone.

[tattybogle in reply to waveylines]

I think best to start a new post for this discussion .... yes, Sorry Guys, got carried away ... will shut up now X waveylines Montheone

[Montheone]

Thank you 👍🏼

[pennyannie]

Hello Montheone

With NDT you dose to the relief of symptoms and not a blood test or range or guideline, all of which were introduced when Big Pharma launched it's on T3 and T4 thyroid hormone replacement on the back of NDT which had been used successfully for over 50 years and long before the " science of blood tests " .

I take NDT and wait 24 hours to find both T3 and T4 in the ranges, T3 proportionately higher than T4, which may be lower than when on T4 monotherapy, and your TSH will likely be low suppressed, as that's just what happens when yo take any form of replacement containing T3.

Also being consistent on timings when you compare to previous tests, obviously a given.

[Montheone in reply to pennyannie]

Thanks - I took 2 grains of Armour at 1.30pm ( 0.5 less than usual as had thought from earlier posts on this that should split dose up throughout the day !) My blood test is 9.15am so approx 18 hours since taken armour so that will have to do 🤷🏻‍♀️

[HeartWoman in reply to pennyannie]

I don't think I can wait to take my NP Thyroid before testing. Is there a problem with taking it at 5:00 am and testing at 4:30 pm on rhe same day?

[tattybogle in reply to HeartWoman]

12 hrs (ish) will be ok for testing the fT4 and fT3 levels using NDT it is far enough away from last dose to avoid the peak in fT4 and fT3 levels after ingestion. and not too long that you would get a 'false low'

The TSH will probably be a little lower at 4/5 pm than it would if you tested at 8/9 am.

TSH is naturally highest in the middle of the night, and falls to it's lowest around 1/2 pm (ish) then slowly starts to rise again.

So if the GP is only looking at TSH result there is more chance they will say "its too low , reduce your dose "

Whether this is a problem for you depends on

a) how low your TSH is , if it's already very close to the lower end of the range, then time of day might make the difference between 'in range' and 'below range'...

b) whether the GP has a brain, and also considers your fT4 and fT3 levels, not just your TSH.