Quantification of 11 thyroid hormones+associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry

Even getting FT4 nd FT3 tested is often extremely difficult or costly. Now these researchers are claiming to be able to measure 11 thyroid hormones and their metabolites in a ridiculously small blood sample. I mean, how big is a tadpole? You don't get a vacutainer-full of blood from them. :-)

Maybe we have to come back as frogs to get properly tested?


It would be interesting to know how much this sort of testing might cost?

Also, I wonder what they would find out by doing this sort of test throughout the day in humans? Would we see incredibly complex patterns - or a fairly simple picture?


Paper in Forefront

Analytical and Bioanalytical Chemistry

pp 1-14

First online: 23 May 2016

Quantification of 11 thyroid hormones and associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry

Martin Hansen , Xuan Luong, David L. Sedlak, Caren C. Helbing, Tyrone Hayes


This paper describes a novel analytical methodology for the simultaneous determination of absolute and total concentrations of 11 native thyroid hormones and associated metabolites, viz. thyroxine (T4), 3,3′, 5-triiodothyronine (T3), 3,3′, 5′-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2), 3,3′- diiodothyronine (3,3′-T2), 3-iodothyronine (T1), thyronine (T0), 3-iodothyronamine (T1AM), tetraiodothyroacetic acid (Tetrac), triiodothyroacetic acid (Triac), and diiodothyroacetic acid (Diac), in 50-μL of plasma or serum. The method was optimized using four isotopic labeled surrogate and internal standards in combination with solid-phase extraction and LC-MS/MS. The methodology was further evaluated using amphibian plasma and serum with matrix-matched calibration applied for quantification. Method detection limits are 3.5 pg T4, 1.5 pg T3, 2.9 pg rT3, 1.7 pg 3,3′–T2, 2.3 pg 3,5-T2, and between 0.3 and 7.5 pg for the remaining six metabolites in 50 μL aliquots of blood sera or plasma. Accuracies and repeatabilities for all analytes were between 88 and 103 % and 1.31 and 17.2 %, respectively. Finally, we applied the method on adult frog (Xenopus laevis) plasma and tadpole (Rana (Lithobates) catesbeiana) serum. We observed up to seven different thyroid hormones and associated metabolites in tadpole serum. This method will enable researchers to improve the assessment of thyroid homeostasis and endocrine disruption in animals and humans.


8 Replies

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  • I can picture myself telling a doctor that there are 11 hormones coming (directly or indirectly) from the thyroid and the doctor's head spinning like something from The Exorcist.

  • What a load of b............ks. This is what all the funding goes on . Kiss a frog,

  • If they can do research like this and eventually use it for helping humans I'm all for it. Sadly though, I think it could be decades before this has any impact on thyroid treatment in humans, if it ever does.

  • At least 50 years for the NHS to catch on.

  • Surely, if there are 11 or more thyroid hormones, many of which we didn't already know about, then NDT is the only suitable treatment for hypo issues - it already contains all the right ingredients, whereas we're not capable of making synthetic versions of some of the hormones we know about, never mind those we don't

  • Not at all.

    There is a cascade of thyroid hormones. T4 is created in the thyroid, then converted elsewhere in the body into T3 and rT3, which is converted into T2, T2 2 into T1, and T1 into T0. So that's six of them. I think the rest are all branches in which another molecule/part of a molecule is involved - they have amine or acetic parts.

    Certainly the thyroid makes some T3 itself. And there might be a vanishingly small amount of T2, even T1. But the bulk of these are produced around the body and within cells. So even if present in desiccated thyroid, the amounts would be absolutely tiny.

    I'd also say that we are perfectly capable of making synthetic T4 and T3. Many here use one or other or both. Why people have issues with them that resolve (at least to some extent) on desiccated thyroid, is one of those questions which really should have been answered but no-one has fully done so. Yet.

    These 11 hormones and metabolites are well-known in the scientific sense of having been identified and subject to assay. In addition to T4 and T3, some have been tried as medicines - some even still are in very rare cases. And many are recognised as potential contaminants of synthetic thyroid hormones with strict limits.

  • I've recently started NDT and found it a completely different experience from T4 +T3. Even though I eventually had a perfect set of blood tests with the synthetics.

    It's slowly dawning on me that this means I have a problem that is not covered at all by the standard set of tests.

  • Oh Helvella........I wish you had been with me at my recent blood test!! I think the phlebotomist would have passed out in a panic if she had listened to you !!

    She asked me what medication I was on and when I told her I had switched back to Armour Thyroid because I wasn't feeling well on my Mercury Pharma T3 she nearly went crazy. What's that? How much are you taking? I explained it was Natural Dessicated Thyroid and I take 1 1/2 grains......Grains? I can't put down Grains!!! Levo comes in Mcgs .......the lab will get confused!!!!!!!!!!!......What more can I say!!

    I got my results at my Endo visit on Monday and Guess what? They hadn't done my FT3! .......I've been having my FT3 tested for 2 years now.......I guess it was just another excuse to avoid the cost of it.....However it has been asked for on my next blood test with a big PLEASE and marked "On Armour"..........Oh Boy!!!

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