Clarifying a MediChecks test result: I thought I... - Thyroid UK

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Clarifying a MediChecks test result

I thought I was fairly clued-up about test results, but my medichecks result has thrown me a little so I'm hoping for some advice/reassurance (I had forgotten to complete the health profile before the test, so have generic advice from the Medichecks doctor)

I have a low T4 (9.3 with reference 12-22)) with a normal TSH 0.5 (0.27-4.2) is this because my FT3 is within normal range? (4.1 in range 3.1-6.8)? Do I need to worry about the low T4? I had the test because I am feeling more fatigued than normal (but then my sleep has not been great so it's hardly surprising)

I take 50mcg of T4 and 24mcg of T3 daily.

Also I'm unsure about my RT3 ratio, as RT3 is low at 7 (10-24)

My Ferritin whilst normal, is low (14 (13-150) could this be cause of my fatigue?

My antibodies are still outside of range TGAB 427 and TPOAB at 196 but I know I have Hashi's and have been GF for 2 years (my results previously were in the thousands so in the right direction if higher than anticipated)

Thanks and apologies in advance for any help - it must be quite tedious being constantly asked to check !


17 Replies

Curious to what has thrown you? You are on a combo T4 (50 mcg) and T3(24 mcg) daily, but you have not got enough active FT3 at 4.1 - to be halfway thru range need about 5. By taking T3 you are effectively bypassing the need for high FT4, but the 'meds' are suppressing the TSH ( said to be good for Hashimoto's antibodies). T4 is largely a storage system, standing by to be converted to T3 for use in all our cells. Spare or unused T4 or T3 might be converted to Reverse T3 to be dumped in the blood, but ranges and ratios of RT3 are a bit unhelpful not indicating why, or where, RT3s have come from. I don't know enough about RT3 to understand the significance of it being reported as 'low' at 7( 10-24). Your ferritin is very low at 14 , this could be causing fatigue, needs to be 100-130 for menstruating women. What about Vit D, B12 and folate levels- could also be low if have Hashimoto's gut absorption problems?


Your FT4 is low because you're taking T3. The body only hangs on to what it wants, and it needs less when you're taking T3. I would be more worried about my FT3, if I were you, because that's still pretty low. That, plus your low ferritin - which isn't normal at all - will be what's causing your fatigue.

Don't worry about the rT3 ratio, that's mumbo-jumbo. But, what was your rT3 itself?

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Thanks for clarifying that FT4 is low because of taking T3 - I don't know why but I keep forgetting this simple fact and comparing to previous (pre-T3). I have now noted in my phone!

Ferritin is first time tested - what is recommended to raise this? Iron? I eat a lot of meat and spinach (generally speaking I have a protein and complex carb GF diet) and also plenty of nuts/seeds. I used to regularly fail blood test when giving blood, but has not been an issue of late, so assumed iron was ok?

My RT3 is 7 (10-24)

Vit D is 75 (50-200) and B12 is 126 (25-165)


Well, spinach won't raise your ferritin level. It's true that spinach contains a lot of iron, but humans can't absorb it. So, unless you really like it, you've been suffering for nothing!

You ought to see your doctor about that ferritin result and get further tests.

Your rT3 is below range, so no issues there. Vit D is a bit low, would be better at 100. And your B12 is good. :)


And if you are eating the spinach with your meat, you are probably blocking the iron in the meat, too. That pesky oxalic acid!

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Are you making community blood donations? How often? Are they automated procedures (“double red” etc.)?

If you are & follow up with your doctor as Greygoose recommends be sure & mention that you have been donating blood. Donating your time to blood banks now & then is equally valuable.


i am a regular blood donor, every 4m or so (i.e. cant remember exactly but as often as allowed for women).

I will make a point of informing doc when i seek iron profile. thx


I don't think continuing to be blood donor is doing you any favours.

I found I had to stop.


Your vitamin D could be better higher around 100nmol

Can you add Folate result?

Ferritin needs to be higher, at least 70. Ask GP for full iron panel testing. It is possible to have high iron and low ferritin. So you can not just take iron supplements. Must have full testing first as excess iron is toxic and dangerous

Personally I need higher FT4 as well as high FT3, so I need higher dose of Levothyroxine alongside 20mcg of T3. I became very unwell with FT4 under half way in range.

SeasideSusie I think found similar problem with having very low FT4.

After all 20mcg (or 25mcg) T3 is not a full replacement dose, so we also need adequate Levothyroxine as well.

What was the total T4 result and ranges?


at one point i was taking more T4 but felt that i had too much (though tbh i can't remember why - based on diary of symptoms i lowered)

I'll raise again and monitor. Thanks


I've just checked and don't have a total T4 score or range


Ok - was this Medichecks including RT3 - if so annoyingly it doesn't include TT4

The standard thyroid plus ultra vitamin test does


That is so very annoying - i went for what i thought was the most comprehensive and worse still paid for 3 of them (both my daughters too).


Yes I just did RT3 (as wanted to double check as my FT4 is higher now, that it wasn't turning into RT3)

I thought RT3 test included vitamins and TT4.

( I obviously didn't read the list properly!)

I usually do standard Thyroid plus vitamins test.


SeasideSusie I think found similar problem with having very low FT4.

I did indeed. I am not well if my FT4 is below 50% through range. I am best when both FT4 and FT3 are around 75%. It took a lot of tweaking of doses of Levo and T3 over a fair amount of time to find where my levels suit me best.

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I do like spinach even though it's clearly not as good for me as i thought!

Thanks for all the advice. i'm reading that dosage needs to be adjusted (both T3 slightly and T4) and see doc for full iron profile and take it from there.

Thanks again for the help - just when you think you know all (at least most) of what there is to know, something comes along to prove otherwise. Thank goodness for this site and it's many experts


Best to eat it with a veggie meal where it can't bind up the other iron that you are ingesting. I like it too.


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