Thyroid UK
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Low TSH & T4, with a high T3. Help with NDT dosage plse

I am new here. (I have been asking lots of questions over the last few weeks!)

My GP always told me I didn't have a thyroid issue, so I have been self medicating for 8 yrs. My GP finally diagnosed underactive thyroid about 2 weeks ago and asked me to come off all meds and offered me only 25mcgs of Levo. I decided to continue self medicating.

I have recently started upping my dosage as the GP' results showed I was under medicating. (These GP results are underneath these new ones.) As she wouldn't test for Hashi's or Vit D, I just got new tests done with Blue Horizon.

Newest test results:

Anti-thyroidperoxidase abs 11.8 (less than 34)

Anti-thyroglobuline abs 18.1 (less than 115)

Ferritin 139.2 (20-150) I have been taking 2 ferrous fumarate a day since last tests

TSH 0.01 (0.27-4.20) I have upped my armour from 6 grains a week to 7 grains

T4 total 65.3 (64.5-142)

Free T4 10.47 (12-22)

Free T3 7.04 (3.1-6.8) My cytomel remains at 12mgs per day since last test.

Vit D 85 (they say 50 plus is sufficient) Currently I am taking no vits for this.)

B12 1406 (they advise to reduce dose at over 725) I am taking 5000mcgs per day, (and BVITS) then was going to drop to 1000 after a month

S.Folate 45.4 10.4-42.4

My results from the GP 3 weeks ago:

Free T3 2.8 (3.5-6.5)

Free T4 8.9pmol/L (10.0-22.0)

TSH 0.22mU/L (0.10-4.00)

Vit B12 567ng/L (180-910)

Ferritin 67ug/L (10-291)


I have had some great advice about my vitamins, from another forum user, but I still need advice on my NDT and T3-Cytomel.

As my T3 is very high now, but my T4 and TSH very low, do I need to reduce my cytomel a bit and up my NDT some more?


8 Replies


Thyroid antibodies are negative for autoimmune thyroid disease (Hashimoto's).

If you left 12-24 hours between last dose of NDT and T3 and blood draw you are over medicated. FT3 should remain <6.8. Where you taking 6 or 7 grains + 12.5mcg T3 when you had the test?

You can stop supplementing iron as ferritin is high in range.

VitD 85 is is the replete 75-200nmol/L range.

You're right to reduce methylcobalamin to 1,000mcg. There's no point in peeing out expensive vitamins.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thanks for taking the time to respond, @clutter:

Yes, I did leave 24hrs between last dose of NDT and T3 before my blood draw, so I can see that in the space of 2 weeks, I have gone from being under medicated to overmedicated! (Possibly because I used to take my NDT and T3 only 3 times a week, where as for the last week, I have been taking it evenly over 7 days, so I think it is "getting in better." I assume this because I have only upped the dosage very slightly after seeing my 1st results. (from the GP, only 2 weeks before the 2nd set of tests.) I am assuming that the major change is taking the medication daily, rather than 3 times a week.

The NDT I take is Armour, (I will be switching to a cheaper brand when this bottle runs out) which of course is a mix of T4 and T3. I was on 7 grains of armour a week when I took the Blue Horizon blood tests. (In 2 grains of armour, there is 76mcg of levo-T4, and 18mcg of liothyronine-T3.) Also at the time of the test, I was on 12.5mcg of liothyronine-T3 per day, which is 87.5mcg per week.

Is it normal that my T3 results would show such a big increase, (too big) when my T4 results have increased only a little and are still too low?

Does this mean I need to increase the amount of T4 I take, whilst decreasing the amount of T3 that I take?



It's a strange regime to dose 3 x per week and you've effectively doubled your dose by taking it every day instead of 3 x per week.

If I were you I would reduce dose to 3.5 grains daily and retest in 6 weeks.


No, I haven't doubled my dose, I've split (almost) the same dose over 7 days, so I am taking 7grains per week, which is only 1 grain per day. (Previously I was taking 6 grains per week, but split into 3 doses. (So 2 grains on Mon, 2 grains on weds, 2 grains on Sat)



Right. I misread your earlier posts.

You are slightly over medicated on 1 grain + 12.5mcg T3 daily. I think FT3 will drop into range if you reduce T3 to 6.25mcg daily.


Ok yes, that makes sense in order to bring the T3 down a bit. Should I be concerned about the fact that my T4 is still too low?


Thank you for taking time to reply. I don't feel any better than before & I have had lots of headaches & some insomnia, so I think it makes sense to cut back a bit.


I'm not a medical professional but TSH works on a negative feedback loop. So, the more NDT you take the lower your TSH will be as this is what tells your body to produce T4 and there is already enough of it in your system. So effectively, you are over medicating. Backing off the NDT will raise your TSH. It seems with the high T3 that it is being converted? But I think you need to look at your Reverse T3 to find out for sure.

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