How much T3 should I add?: Please could somebody... - Thyroid UK

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How much T3 should I add?

AleB profile image

Please could somebody help me work out how much T4 to reduce in order to make room for T3? After another 8 weeks at a reduced levo amount of 125/100/100/125/100/100/125 my results as follows:

CRP HS <0.3m/l (range 0 - 5)

Ferritin 82 ug/L (range 13 - 150)

Folate - serum >20.0 ug/L (range >2.9)

B12 Active >256.0 pmol/L (range 25.1 - 165)

Vit D 106 nmol/L (range 50 - 200)

TSH 1.32 mlU/L (range 0.27 - 4.2)

Free T3 3.8pmol/L (range 3.1 - 6.8)

T4 19.3pmol/l (range 12 -22)

TGA <10.0 IU/ml (range 0 - 115)

TPA 18.3 IU/ml (range 0 . 34)

Test was fasting, done at 8.50am, all biotin/iron/B12 supplements not taken for 10 days.

My blood pressure fluctuates, as does my weight, pain in lymph glands in neck, cold, muscle weakness, brain fog, blurred vision, trouble walking any distance, and completely and utterly the worst fatigue I have experienced so far.

I wondered if I could safely reduce levo to 100 for a week or so and then introduce T3 (I have 5mcg tablets from previously trying). I have no help from NHS endo, just refuses to accept T3 is needed. All tests had been done privately through private endo DI02 gene polymorphism. I have been strictly gluten free for 3 years and dairy free. Had another batch of antibiotics from 25/05/21 for kidney/UTI, still awaiting results for this from GP. What the GP and Endo don't understand, I can ply myself with as much levo to the very top of range and over range, but I just can't convert it! Sorry for the long ramble, I have realised that if I want to have some sort of health and mobility I am going to have to do this on my own!

Thanks again for anybody who can help ... again!

14 Replies
SeasideSusie profile image


I am not medically qualified so I can only speak from my own experience.

If those were my results I wouldn't be reducing Levo. Taking T3 is going to reduce your FT4 anyway, so why make it lower to begin with. It's 73% through it's range now. Trial and error will tell you where you need both your FT4 and FT3 levels. You might be one of those people who are fine with a low FT4 as long as FT3 is in the upper part of it's range, but you might be one of those people, like me, who needs both FT4 and FT3 fairly well balanced higher in range. I need mine about 60-70% through range. It takes a lot of patience, a lot of gradual tweaking (just a bit at a time so you don't overshoot your sweet spot) to find what we need.

So if it was me I'd just add 5mcg T3 now. You could see how it goes, if all OK then you could add another 5mcg in a couple of weeks. But you might want to be more cautious and take it very slowly, if so then retest after 6 weeks, check your levels and how you feel, then make the next adjustment. You may find that 3/4 of a tablet is enough, maybe a full tablet, possibly a bit more, just take it slowly, give the change of dose time to work (6-8 weeks) and retest before making another change.

all biotin/iron/B12 supplements not taken for 10 days.

Exactly what are taking? Active B12 and Folate are high so you certainly don't need a separate B12 supplement and you could just take good quality B Complex a few days a week to keep them at good levels.

Is iron prescribed? You've reached a good level, just need to maintain it now and you can probably do that by eating iron rich foods, maybe liver, liver pate or black pudding once every week or two.

AleB profile image
AleB in reply to SeasideSusie

Hello SeasideSusie, thank you once again for coming back to me. I have been taking Thorne Basic B Complex x 1 per day, Solgar B12 1,000 ug x 1 per day and Ferrous Sulfate 200mg x 1 x 3 per day. I think it best I stop the B12 for a while, will have to monitor the ferritin levels as this has always been a tricky one for me. Will keep the levo regimen going and add 1.25mcg of T3 for a couple of weeks and see how I go from there, low and slow again! Thanks for your advice again.

AleB profile image
AleB in reply to AleB

Just another question, sorry ... I have my 2nd covid vaccine due on Monday, 31st May ... might just hold off with changing the thyroid meds until a week after this. (wouldn't know if the vaccine gave me side effects, as I feel pretty rubbish most of the time anyway)!!

SeasideSusie profile image
SeasideSusieAdministrator in reply to AleB

None of us know how the vaccine will affect us so, yes, probably a good idea not to make any changes until you've had it and had time for things to get back to normal if you are affected in any way.

AleB profile image
AleB in reply to SeasideSusie

Thanks for the advice Seaside, It's really my last hope with T3 this time ... I've spent the last 6 months practically bed bound! Will hang on for another week until the 2nd vaccine has hopefully not caused any ill effects and try with the T4/T3 regime!! Thanks for your help.

SeasideSusie profile image
SeasideSusieAdministrator in reply to AleB


Sounds like a plan for the B12, our B12 store is generally good for a couple of years and taking the B Complex should be enough once we have a good level.

As for T3, why take only 1.25mcg? I don't think that will help at all. Your FT3 is dreadfully low, start with 5mcg and add in 5mcg increments, you can always slow down when you get nearer the upper part of the FT3 range.

When I said you may find 3/4 of a tablet may be enough, I was referring to full dose 20mcg tablets (or 25mcg if you end up self sourcing T3) which you will inevitably end up with I'm sure, not your 5mcg tablets, that will never be enough for anyone. Sorry I didn't make that clearer.

If you prefer to take it slower then that's OK but I don't think you'll find it helps at such a low dose.

AleB profile image
AleB in reply to SeasideSusie

Know you where clear Seaside, it's just from past experience I need to go pretty low and slow otherwise I get heart palps, insomnia etc.

SeasideSusie profile image
SeasideSusieAdministrator in reply to AleB

OK, you know yourself well enough so go with what's best for you. It's a long, slow journey adding T3, I'm still making changes 4 years down the line, you think you've got it sussed then something comes along and upsets the apple cart!

AleB profile image
AleB in reply to SeasideSusie

Too true, I know what you mean, the past 3 years have been pretty testing to say the least. Fingers crossed, and thank you so much for your help.

SlowDragon profile image

Yes, I would agree...reduce levothyroxine to 100mcg daily

Do you always get same brand of levothyroxine

As you’re dairy free are you on lactose free levothyroxine?

5mcg T3 tablets by Morningside healthcare aren’t lactose free

You might need lactose free T3

Assuming trialing on 5mcg tablets

3-5 days after reducing....add half a 5mcg tablet T3 waking and (assuming that’s ok) add other half of tablet mid to late afternoon

After 3-7 days start taking 5mcg waking and add second 5mcg dose mid- late afternoon

Hold at that dose 6-8 week’s and retest

all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

When on T3, day before test, split dose into three smaller doses roughly equal 8 hour intervals. Taking last dose T3 at roughly 8-12 hours before test

So on 2 x 5mcg before test

5mcg 7am

2.5mcg 2pm

2.5mcg at 9pm (assuming test is 9am)

You might find this dosing regime works best daily anyway

AleB profile image
AleB in reply to SlowDragon

Thanks for you reply SlowDragon, I think I am going to try just adding the first dose of T3 at a shaving of 1.25mcg to my existing levo amount, I can see how that goes before reducing to 100mcg ... from experience, anything less than 100mcg and I am a non functioning wreck, collapsing and short of breath! I am pretty scared about doing this on my own, but I've tried so hard to make T4 work for me, it doesn't and the Endo has flatly refused T3, private Endo made me really ill on 75mcg T4 and 3 x 5mcg per day (I didn't sleep for 2 weeks).

SlowDragon profile image
SlowDragonAdministrator in reply to AleB

Yes....I reduced levothyroxine for 3 days (from 125mcg to 112.5mcg) before adding 2 x 2.5mcg T3 initially. Even that was a “whoosh”

After a week...I reduced levothyroxine again to 100mcg and 3-4 days later increase to 2 x 5mcg

Held at that dose 8-10 weeks before retesting (was better in many ways...but also difficult to tolerate...almost chucked it in weeks 5-7 ...but I have learnt from bitter experience I always feel worse approx 5-7 weeks after any dose change)

After blood test results....T3 was increased to 20mcg per day by endo (10mcg at 7am, 5mcg at 3pm and 5mcg at 11pm)

After few months Ft4 was bottom of range, increased levothyroxine back up, initially to 112.5mcg ....then eventually to 125mcg

Stayed on this 3 years.

Recently reduced levothyroxine to 112.5mcg ....and increased T3 to 25mcg (as 4 doses at approx 6 hour intervals)

AleB profile image
AleB in reply to SlowDragon

Thank you SlowDragon for taking the time, definitely agree with you ... it takes me nearly 8weeks to feel dose change and for things to settle, I think this is where I may have come unstuck with T3 in the past and it's such a juggling act with T4 it's hard to tell. I thought if I go low and slow on the T3, at least I will know what to change rather than changing both together ... my adrenals always take a battering!! x

SlowDragon profile image
SlowDragonAdministrator in reply to AleB

Exactly....I get sharp needle like pain in adrenals when levels are off ...or changing dose

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