Thyroid UK
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Latest Thyroid Bloods - timing may be an issue

Just got my latest bloods back, my results are as follows: -

Total T4 66 (59-154)

Free T4 12.5 (12-22)

Free T3 8.3 (3.1-6.8)

TSH 0.11 (0.27-4.2)

TPoAb 89.4 (0-34) Positive

TgAb 37.2 (0-115) Negative

I have had the Autoimmune Thyroiditis for a while - so no shock there (G.Free for 2 years, all vits good etc, but still not dropping.

BUT My main concern / query is I was advised to take my NDT 2-4 hours before my blood draw, and state the exact timing to my doctor. SO, these results are exactly 3 hours after taking 1Grain of Nature-throid. As such, am I right in thinking this is why the FT3 is over range, and would probably slip back to normal after a couple more hours?. I take 2 Grains daily, split into 2 doses.

Also, what's going on with the FT4 being so low in the range - i'm a little confused by this, would It warrant an additional 25mcg of Levothyroxine along with my morning dose of NDT?

Apologies for my many questions again - you Admins do seem to always put me right and your advice has been spot on in the past, so many thanks in advance.


5 Replies

FT4 is always low when taking any form of T3, so Don't worry about that.

Who advised you to take your NDT before the test? That was bound to make the FT3 high. I often Wonder if they do that so that they can say, oh, your dose is too high, you have to reduce!

If you took your NDT 3 hours before the test, what time was the test done? TSH is highest early in the morning, so it's possible that yours isn't as high as it might be. Did you fast before the test? Because eating will lower TSH, as well.

Sorry, I'm not an admin. :)


Grey goose, many thanks for your reply, that's very helpful. The doctor is an excellent GP who prefers levels measured whilst taking supplements and other medications to get a truer picture of chemistry. I totally agree with the usual methods for T4 to get TSH as high as possible by testing early am before meds, but if it wasn't for the silly prescribing guidelines I suspect this practice would not be nearly as common (or necessary). Sincere apologies for the comment re Admin, it wasn't supposed to read like that, but having reread it now it looks very unkind and ungrateful! Slapped myself accordingly😉. Comments from anyone are always welcome, as I still have a great deal to learn so the more people who reply the better it is for all of us. No offence intended, and thank you for your time in replying. K. Regards, Rick.


lol No offence taken, Rick.

Taking your dose before the test isn't going to lower the TSH much, but eating, or having it late in the day is going to lower it.

Taking your dose before the test is going to raise your FT4 and FT3. I really Don't understand your doctors methods. I just Don't see what information he can gain that way. What he needs to know is what levels are when you need your next dose. That is far more telling as far as I can see. What is he going to make of your FT3 so far over range? Is he going to reduce your dose?


Hi Rick

I had this same problem last year.

With my GP refusing to discus thyroid again, I saw a Private Doc, (from Louise's list) who prescribed NDT, then insisted I take the NDT before the (Blue Horizon) Test - so he could see exactly what the NDT was doing for me, in the body.

Predictably my Results were over-range.

T3 8.03 (3.1 - 6.8) TSH 0.01 (0.27 - 4.2)

Unlike yours, my T4 was also over-range at 23.23 (12 - 22)

So he reduced my dose and the next Test (again insisting I take the (now lower) dose before the blood draw). T4 was then under-range at 10.6 (12-22) with a TSH of 5.76.

After this roller-coaster 6 months of hell, I decided the lovely, helpful people, here on HU knew better than the Private Doc on Louise's list, and I have since been reading, learning and doing my own thing, with considerably more success.



Hi Stoneym - thanks for that, it's a help to know there are other GP's working on the same theory. Seeing the blood chemistry effect of medication is a logical approach as it shows exactly what the NDT is raising the peak levels to. This could open up a whole new debate on timing - the more I think about this, the more it makes sense to test for peak levels! This is obviously a lot harder with hormones such as T3 & T4 as they have different half-lives, and T3 in particular does seem to fluctuate more. Testing soon after taking your last dose requires a very astute and "knowledgeable" doctor to properly interpret the results, so I'll see what response I get - my review is in 3 weeks! I am self-medicating at 2 Grains, and feel very well at the moment so I hope I don't get told to reduce.

Thanks for your time,


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