Should I increase T4 or T3 or both?

[Obvs]

Back in September 2024 I started a trial of combination hormone therapy after finding that I had continuing symptoms of hypothyroidism despite being on 150mcg of Levothyroxine.

I’m on a gluten and dairy free diet, I take a B vitamins, and vitamin D3/K2 along with Magnesium, tested vitamins are good. Cortisol levels are normal.

My blood test results had been indicating high free T4 and middling to low levels of T3. Lowering doses of Levothyroxine just lead to increased symptoms.

I started a trial of T3. At the outset of the trial I was asked to drop the Levothyroxine dose to 125mcg and add in the 10mcg of Liothyronine.

I did an NHS blood test before 9am and 24hrs since the last T4/T3 dose (I wasn’t splitting the dose at this stage). I still had some symptoms but when I started the T3 I felt like I could breathe properly.

04/10/24

TSH: 0.05 (0.4-5.0 mU/L)

T4: 13 (9-19 mU/L)

At the review in November ’24, I felt I needed more T3. I was asked to reduce the T4 to 75 mcg as I increase the T3 to 20 mcg and split the dose.

I initially had some major symptoms: dry hands and feet with split skin on fingers, headaches for days, constipation, mood crashes, cold hands and feet, low body temperature etc. This has improved a lot but they still pop up, my skin is still very dry, I find I sleep very heavilly and I don’t function well until the mid afternoon and after my second 10mcg. Overall I feel better in many respects, but I haven't hit the spot.

06/01/25

TSH: 0.04 (0.27-4.2 mU/L)

T4: 11.8 (12-22 mU/L)

T3: 5.0 (3.1-6.8 pmol/L)

My question is should I increase the T4 or T3 or both to feel I’m on the right dose or should I give everything more time to settle.

Thank you for your thoughts.

[Lalatoot]

Obvs Only change 1 thing at a time as that way you can monitor cause and effect. At this stage where you are trying to find levels that suit you you need to methodically change one dose by a small amount then wait 6 - 8 weeks monitoring how you feel - then do bloods sticking to the same blood draw protocol each time - and base your next move on your blood results and how you feel.

Because your ft4 result is low, I would increase levo this time. As your ft4 is under range I would suggest a 25mcg increase.

Wait 8 weeks then consider look at blood results. Increasing levo will cause and increase in ft3 as well as ft4 so you may come to a point where you wish to decrease you liothyronine dose to accommodate the increase in levo dose.

My initial combo prescription was 50mcg levo and 20mcg lio. It took 2 years of methodical changes and blood tests till I optimised my doses. I ended up on 100mcg levo and 7.5mcg lio.

You will read on here folks saying that they need their ft4 and ft3 at 70% through the range. Don't aim for anyone else's well place. You can waste months trying to reach a certain level only to find that it doesn't suit you. You need to find what is best for you.

[Obvs in reply to Lalatoot]

Thank you for your response Lalaloot. Yes I thought a levo increase might help. Endo wasn’t keen saying any increase might lead to over treatment and Atrial filbrilation. I don’t have any negative heart symptoms at present.

[tattybogle in reply to Obvs]

i agree with lalatoot , i'd address the levo first as fT4 is below range , they have reduced it by far too much in an attempt to compensate for the addition of T3 , but they tend to do that to everyone and a lot of people then find it drops their ft4 level much more than they / or endo were expecting.

also increasing T3 by 10mcg at a time is a very heavy handed approach , so it's possible you don't actually need the full 20mcg , and you may need to tweak that down a bit at some point.

as for endo saying 'levo increase might lead to over-treatment' ,,,, well perhaps if they had thought along those lines before increasing T3 by 10mcg, you might be closer to the right balance by now.

[Obvs in reply to tattybogle]

Thank you for your response tattybogle,.

Yes I think the endo is trying to keep it effocient, which I appreciate, but I think small changes might be be particularly needed at this point. I was more concerned with long term effects of too much T4 and consequent high rT3, which has come down a lot since I started the combination T3/T4.

I know the jury is still out on rT3, but it seemed to be causing issues I my case. I had a DNA test which said I had one of the mutations making conversion T4 to T3 problematic and unreliable, so having theT3 has made things more steady. It took a bit of adjustment but I benefited, I think I need to slowly tweak it, as you suggest.

[tattybogle in reply to Obvs]

i had top end ft4 ( 91%) before adding t3, ( doing it DIY , not endo)

i reducing levo by just 12.5mcg ( and gradually added 9mcg T3) ...... my ft4 dropped much more than i was expecting it to ... 56% .

i felt very weird , so put levo back up to where it was before and felt better quite quickly , but i'm still not feeling anywhere near right .....shame , as i was hoping for a T3 eurika moment .....but i am persisting . currently giving 87.5mcg +6.25mcg T3 (in one dose) a whirl.

hopefully we'll both figure it out in a few more months ,, best wishes

[Obvs in reply to tattybogle]

Thank you tattybogle.

Yes it is a very fine balancing act. Good luck with your progress. 💪

[Lottyplum in reply to tattybogle]

My Endo didn't reduce my levo when I started T3+T4 didn't drop either so just shows how different we are+that trial+error to get to where our levels suit us as individuals is literally trial+error!!

[Obvs in reply to Lottyplum]

Thank you for your response

Yes I’m registering that fact and willing to try a few options. Perhaps AI could work out what your best path is approximately and speed up the whole process

Good luck with your trial and error

[Lalatoot in reply to Obvs]

Endos are very twitchy about combo treatment and dose changes. I was lucky that my T3 trial was during covid so I could keep the endo at bay as it were as they were not doing face to face.

I had to listen several times to their caution about heart and bone problems. I explained that as long as my ft4 and ft3 were in range then I was not concerned about tsh as, in my opinion, that feedback loop had broken. They noted in my records that I accepted the risks of a suppressed TSH and it stopped being an issue.

[Obvs in reply to Lalatoot]

Thank you, good to hear your experience. And my GP seems to be ok with suppressed TSH as long as an Endo says it’s ok.

Personally I think TSH rises cause me headaches, so I’d rather accept the possible risks if there are any from it being suppressed.

[Star13]

What I was going to say I’m now not going to!

I’ve got a very good Endo who ignores my deficient TSH and always tests FT3 and 4 plus other hormones. The first thing he asks me is how do you feel and decisions are always a joint thing.

I’ve just been in your position. My t3 went just over range but my t4 was struggling a bit. Also my estrogen was below detectable range. So he upped HRT and lowered my T3 slightly which sent both FT3 and FT4 down by 2 points. He then increased the Levo by 25mcgs which was where I was last week when I asked a question on here the same as yours. Most people said raise Levo by 12.5mcg, but when I suggested this to the Endo he said that he could see from my other results that I was not converting well so there was no point in doing that so I should raise T3!

So as I started, I would have said what the others have said but having just experianced my situation the caveat would be are you a good converter if you increase Levo?

[Obvs in reply to Star13]

Thank you for your response.

Well I don’t seem to be a very good converter, but I must have been converting some Levothyroxine, just not enough when when only taking Levothyroxine. There’s so many variables, it feels like you have to use your intuition. I’m definitely not overtreated despite going over range with the Liothyronine, I think it only goes over for an hour or two as I have done a blood test in the afternoon when starting out and it drops to just over mid range by 3 o’clock.

[TiggerMe Ambassador in reply to Star13]

I'm a shocking converter but if I let my fT4 drop below 50% I feel utterly awful... been there, thanks to an Endo 🫤 that was without messing with my T3 dose but I'd say I felt even worse than before adding T3! 🤷‍♀️

[Obvs in reply to TiggerMe]

Thank you for the reply.

That’s interesting to hear, one assumes that poor converter doesn’t need Levothyroxine as much or that it might hamper the action of the added Liothyronine.

I did adjust to the drop in Levothyroxine to some extent, the broken dry skin returning I think has indicated that my skin defenses might be low, and I now have periorbital cellulitis.

The added Liothyronine has improved my overall and mental energy levels, so I wouldn’t want to change that….Can I have both?

[TiggerMe Ambassador in reply to Obvs]

Yep, I went along with the request to lower my T4 dose though fT4 only at 70% as I had found I had the DIO2 gene so maybe T3 only was the way to go 😳 12 weeks later and total loss of function, return of horribly dry skin and the intense itchy chins... having previously had 6 months of good recover after initially adding T3... it took me 6 months to recover from that 'experiment' and my adrenals really suffered

Interesting you mention your eye condition as periorbital oedema is a hypo condition but I'm assuming you have an infection if they are saying cellulitis?

T4: 11.8 (12-22 mU/L) -2%

T3: 5.0 (3.1-6.8 pmol/L) 51.4%

It'll be interesting to see where you are after the next test, yes you can add both but ideally not at the same time so you know what effect each is having

[Obvs in reply to TiggerMe]

Thank you. Yes it is cellulitis and I’m on strong antibiotics (which I know will cause issues too). I looked up whether there was an association with being hypo and there is, not sure why.

I will request and try a small increase in Levo and see how things go.

[TiggerMe Ambassador in reply to Obvs]

Just re-reading your history... so since Sept 2024 you have changed from 150mcg T4 to a combo of 75mcg T4 and 20mcg T3... WOW! I'm not surprised your body is reeling slightly

So that is a massive change done in a short period with one of the T4 drops being by 50mcg when guidelines say never more than 25mcg either way...

To me your Endo is incredibly heavy handed and has put you on a big dose of T3 when initially just add a small dose of T3 (5mcg) to your 150mcg T4 ought to have been the first step to acclimatise your body and see how much it dropped your fT4 level and bought your fT3 level up. Doing things too quickly and in big steps often means missing your sweet spot

What was your fT4 level before starting T3? I have looked back and see 125mcg had your fT4 at 60%

 tattybogle and Lalatoot have given you some great insights

[Obvs in reply to TiggerMe]

Thank you for your comment

Yes in April 24 it was at its highest

TSH: 0.04 (0.27-4.2)

T4:23.5 (12-22)

T3:4.8 (3.1-6.8)

Still had symptoms and had stopped taking HRT but dropped dose to 125 for a while and felt so rubbish so increased it again and did a test to see where everything was May 24

TSH:0.06 (0.27-4.2)

T4:21.5 (12-22)

T3:4.1 (3.1-6.8)

A doctor might think that I was going in the right direction, but I couldn’t cope with the change

On 140 mcg T4 in July 24

TSH: 0.03 (0.27-4.2)

T4: 21.9 (12-22)

T3: 4.7 (3.1-6.8)

It was a challenge to find the answer, and I was never feeling right so I stopped testing. Add into that foggy thinking and it’s a losing battle.

[TiggerMe Ambassador in reply to Obvs]

You seem to be taking a large dose of T3 and yet your fT3 level hasn't risen by much at all? How long after your last T3 dose was your latest test?

Your July 24 results don't show you as a terrible converter so you are certainly able to make use of T4, had you optimised your vits and mins at this point?

Free T4 (fT4) 21.9 pmol/L (12 - 22) 99.0%

Free T3 (fT3) 4.7 pmol/L (3.1 - 6.8) 43.2%

T4:T3 Ratio 4.660 

[Obvs in reply to TiggerMe]

Thank you for your response Tiggerme.

Yes my vitamins were good., but I still had symptoms of hypothyroidism, it just wasn’t enough. I really tried to keep it simple by tweaking the dosage. I don’t have the DIO2 gene, it’s another mutation that precipitates conversion of T4 to rT3 (I’ll look at the analysis again to check). Remaining low (for me) on T3 was potentially having long term issues, not least memory etc.

I think an extra bit of Levothyroxine may be the key now I’m trying Liothyronine, and I’ll be ready to adjust T3 accordingly as suggested. I don’t think T3 only would suit me either especially after reading your experiences.

[redhead41]

I would in tease the levo - 75mcg is a relatively small dose. Probably need to do it slowly. Also splitting the t3 into 3 doses across the day worked best for me - 1st dose at 6am, 2nd dose at 11 am and third dose at 4pm. Taking levo at night has made it easier as well. Bld test needs to be 24 hours after t4 and 12 hours after t3( this means having to move the last dose of t3 the day before).

[Obvs in reply to redhead41]

Thank you redhead41 for your response.

That’s a good idea. It might stop the morning slump. I did try to take Levo at night before trialing Liothyronine, and I completely derailed, but perhaps now I’m on the Lio I could try again. 🙂

[Sleepman]

I am reading it can take a long time for TSH to recover, yours has been low for a while and perhaps your endo is not factoring this in when trying to lower your T4 so dramatically. It does not seem the priority at the moment, it can come later ?

Low TSH risks osteoporosis and heart issues but so does being underactive and sat on couch. 1 hr 13 mins into

"Why you might not feel better on thyroid treatment talk by Dr Georgina Conway" Thyroid trust on you tube.

thyroidtrust.org/events-lis...

I am on a similar journey to you and found the video very useful and need to rewatch (at x1.5 speed)

Good luck

[Obvs in reply to Sleepman]

Thank you for your response Sleepman.

Yes I am obviously a bit concerned about low TSH , but more concerned about present health in all ways, I need to have a life.

Stress is a big factor in my ability to convert Levothyroxine, I need to be able to cope with normal stress. I am starting to feel stronger physically with the Liothyronine, so that is a good sign.

I’ll take a look at the video, thank you

Best of luck to you too

[Sleepman in reply to Obvs]

Sorry my point was not that clear, but I was trying to say TSH is not the be all. My TSH is low. I dropped my T4 dose to try and improve it (for the doctor) but felt worse so increased again.

[Obvs in reply to Sleepman]

Thank you Sleepman, yes I understand your point about TSH.

I suppose my question was if you didn’t raise the dose of Levothyroxine , would things improve by themselves once your body adjusts to taking Liothyronine regardless of TSH (a bit of a question on the time it takes for Liothyronine to work ?)

[Star13 in reply to Sleepman]

“Low TSH risks osteoporosis and heart issues” as a statement taken in isolation is just scaremongering! There are many reasons for low TSH, unfortunately many Endos don’t bother to properly find out out what they are before spouting the above!

[Obvs in reply to Star13]

Thank you for your response.

I’m sure it’s a general rule, but not necessarily accurate for individuals and certainly not worth using for dosage levels. On 50 mcg of Levothyroxine back in 2020 my morning results were

TSH:0.2 (0.4-5.0)

T4:14 (12-19)

And my T3 must have been well below range.

[redhead41 in reply to Star13]

I believe once on t3 meds the body has enough thyroid hormones circulating that the pituitary no longer needs to produce tsh. Hence it is suppressed.

[Obvs in reply to redhead41]

Yes. And even artificial hormones may do the same as I was only taking T4 at the time it was suppressed