T3 Only - What Dosage

I have been on T3 only for 10 years, I was continually encouraged that i MUST take high dosages and have struggled so hard.  Recently I have reduced dosage and feel much better so now only take 43.75mcg split over the day 

25mcg waking, 12.5mcg @ 5 hrs later, 6,25mcg @ 5 hrs later

I was told buy so many 'top' thyroid docs and support groups that you must use 75mcg +

I overstim terribley on any more, but I know I wake with no meds in me as my TSH is suppressed - but unsure of the answer (considered a little timed release before sleep)

Anyway for those on T3 only what dosages are you taking


28 Replies

  • I take T3 only and have never read that it should be a stipulated 75mcg. That's far too high for many.

    There's no 'set' dose as we are all different. The best way, with any thyroid hormones, is to judge how you yourself feel, i.e. is there clinical symptoms? Do you feel well? Sleeping well etc.

    You have found your suitable dose to be 47.5mcg of T3.

    I don't split my dose at all and it lasts until next morning. I feel well and healthy. I take under 40mcg T3.

  • No sadly cant take T4 and have never got T3 dosage correct.

    So on your dose of below 40mcg what are your waking readings, so do you have a totally suppressed TSH and T4?

    What I find is my T3 totally suppresses T4 (as expected) and i wake with a totally supressed TSH so no T4 reading but also T3 so low Im totally hypo, it then takes me at least 2 hours to get any function until the T3 absorbs

    Still then I sit with no T4 and T3 in range - I am told if your on T3 replacement it should sit above range to compensate for the no T4 levels

    Every doctor (cant name them here but think of every top worldwide name you can think of as I consulted with them all) + all the T3 groups all say you need +75mcg and that you must sit with constant leels of T3 to compensate for the lack of T4 levels.

    It makes sense if you have a continually supressed TSH and no T4 that you must need higher T3 levels, so waking with no levels of anything is not a good thing, but I dont know the solution other than adding some timed release?

  • My blood tests are fine and TSH isn't suppressed.

    I rarely take note of anything untoward these days. Only if I feel a bit 'off' I take pulse. Sometimes it's a little fast but it soon settles. (this is only very occasionally).

     Some people are thyroid hormone resistant and have to take super-doses in order to relieve their symptoms. 

    When I have blood test I have the earliest possible and fast but drink water. I also allow 24 hours between my last dose of T3 and the test. This allows my TSH to be at it's highest and that's what most doctors only appear to take notice of.

    Re thyroid hormone resistance. I shall give you the following link. The doctor has now died and his site is archived but there's lots of good info.




    When the blood tests were introduced they were for the use of levothyroxine not any other thyroid hormones.

    NDT we took until symptoms went.

    We know now, due to tests, that if we are on T3 only that our T4 will be very low (i.e. we're not taking any neither are we producing much if thyroid is still sending out some)

  • Riannabri,

    When I was on 60mcg T3 I took it every 8 hours.  Now I'm on T4+T3 I take the first dose on waking and the 2nd at bedtime.

  • Gosh that is very unusual the TSH normally gets totally supressed with T3, so for me mine is totally suppressed even after 24hrs at <0.001 and no T4. That is probably why you are well as you still produce the T4.

    The link - That was one of the doctors I consulted with and his wife for over a year, it was stated to me that I must take 75mcg +.  After seeing this very doctor that is what destroyed my life as he did not check my adrenals and gave me T3 without any adrenal support - I ended up in hospital in a full blown adrenal crisis.  

    So this is why for the last 10 years I have been trying everything to get well, I have since consulted with all different thyroid docs all over the world that use T3 without success sadly

  • Riannabri,

    Your T4 is suppressed because you are taking T3 only.  It's the amount of T3 or T4 you take which suppresses TSH.  If you have FT3 high in range it doesn't matter that FT4 is low/non-existant.

    My TSH wasn't suppressed on 75mcg T4 + 20mcg T3 but was suppressed on 75mcg T4 + 30mcg T3.

  • Yes of course it is, I am totally aware of why my TSH is supressed - Hence why my T4 is low. The problem is I can not tollerate T4, Can not tollerate high doses of T3 so need to re look at supressing my TSH less and letting my T4 raise back up as this was when I was at my best.

    Ive tried for so long to up my dosage of T3 but that has not worked so as galathea says try the opposite

    Its a fine balance for me as in addition to Hashimotos I also have central hypothyroidism so a naturally low TSH, Low T4 and Low T3 so any dosage change creates havoc.

    Difficult one for me im afraid

    The funny think is I was an endocrinology support worker so know the science inside out but sadly it doesnt work for me !!!!!!

  • Do you still have some thyroid function, then?

  • There's an account that might have some overlap with yours on Paul Robinson's, Recovering with T3 site: it's Sue's Story Continued (NB, Sue has some thyroid function and doesn't have Hashi's but this is more of an indication that some people experiment and feel better with lower amounts tho' maybe only if, like the writer of this account, it's more an adrenal than thyroid issue).

    "The issue I had with my T3 dosing was that my blood pressure was always high (ish), even though I had hypo symptoms. I experimented for a while, but when I stepped back and thought about it, I decided that the blood pressure was the significant factor. I also remembered a doctor saying to me that if you take too much T3 your body sometimes "shuts down" to protect itself. Logic told me then, that I was taking too much (blood pressure) and my body was shutting down (hypo symptoms). On this basis I gradually reduced my dose over a period of a few months. The hypo symptoms lessened and I felt better. I continued with this until I was taking nothing. After a few days of zero T3 I felt like I was "walking off a cliff". Not a good feeling. I therefore took a small dose of 6.25mcg at 4.45am (always my optimum timing), and felt better immediately. I experimented with a second dose, eventually settling at 6.25mcg at 10.30am (5 hours after first dose). I sometimes get palpitations around 7-8pm, and make a point of adding a third dose of 6.25mcg at 4pm the next day...


    I guess the other conclusion I've drawn is that the problem for me was probably exhausted adrenals more than any massive thyroid problem. Once my adrenals got a bit of T3 at the time they needed it, my health came flooding back. Which is why I'm getting away with such a small dose of T3. ...I suspect, my need for T3 links to my peak requirement for cortisol, ie early morning & before 1pm. Again, this may mean I won't need T3 forever. I never stood a chance of getting this diagnosed by a GP or endo. I believe there are thousands of fat knackered middle-aged women enduring the 'half-life' that I had. I'm literally buzzing with energy these days. Couldn't have wished for or imagined it was possible to feel this way!"

  • Thanks for your reply, - Can I ask what total dosage you take and the timings?

    I do have hashis VERY high TGAB's hence why I have to keep my TSH supressed.

    I am on hydrocortisone with each T3 dosage and was taking 6.25mg in addition to my other dosages at 10pm for 2 years but it just did not work I felt so much worse, as I say I have dropped that now so am on 

    43.75mcg split over the day

    - 25mcg waking, 12.5mcg @ 12 noon, 6,25mcg @ 5pm

    I tried the PR early dosing but it just cant work for me as im on hydrocortisone (I cant come off that as I have totally no cortisol production)

    So I am thinking perhaps a timed release night dosage?

  • Really love this apt expression... 'fat knackered middle-aged women'

  • Thats the funny thing, wake totally hypo, have no T4 hardly any T3 and slim *8 stone WEIRD

  • Oh bugger all that multi dosing and high amounts stuff....  Why would you put yourself through it?        Have you thought about just dosing once a day, with a sensible amount so as the saturate the cells....    Say,   20 or 30 mg .....   If its not really working for you.. dont just take more and more.....

    Take your temperatures regularly and plot the averages once a day on a graph.... That way you will. E able to work out whether its thyroud or adrenals causing the problem.    See my earlier post about temps......         Suppose you have had an adrenal saliva test so you can see exactly when they are running low?       I only had problems in the afternoon, so didnt need to dose cortisone in the mornings.......

    Heres the link to the temperature charts.....   healthunlocked.com/thyroidu...

    G x

  • That made me giggle as I was just thinking the same, Ive been on this rollercoaster for over 10 years.

    Yes my adrenals are crashed both saliva and blood show Zero, and I continually fail a synathcen test - so have to take the hydrocortisone and florinef

    I have Hashis and was told to keep my TSH supressed to stop the antibodies but its made no difference whatsoever after 10 years there still in the 1000's

    After all this time I wonder if I wean off the T3 larger dosages if my TSH/T4 will rise - I felt my best (not well but not housebound like the last 10 years) when I was on 25mcg T3 am and my T4 just sat at 6 so supressed by the T3 but I had something in reserve

    May be time to give it a go as although I feel hypo I am definately a tad better by stopping that night time dose

  • My antibodies were at 1760 some 20 years after being diagnosed....  Despite having a tsh of 0.02 for years.      I am pretty well now and the roller coaster has stopped, since i took cortisone for a couple of years....  And put myself on ndt, which doesnt work in quite the same way as the fast acting synthetic stuff.    Heres an explanation.       thyroid-s.com/natural-desic...

    Xx g

  • You know I think this makes sense and is worth a go - I cant take any form of T4 and NDT well that was horrific for me.

    So im wondering should I reduce gradually or cold turkey to just a am dosage of T3 - Lets pray my natural thyroid kicks in after 10 years of supression - intuition says slowly??

    What NDT are you on

  •  I use Naturethroid. Or Thiroyd.      I tried thyroid S and erfa but as They are both formulated to have a longer shelf life i couldnt get on with them.....

    Xx g

  • If you still have any thyroid function left - if the Hashi's hasn't killed it all off - then it will come back. I speak from personnel experience, there. :)

  • I take 60mcg daily in one dose 1 hour before food.....

  • Thanks for your response, Thats interesting, so I assume you sit with a supressed TSH and no T4 reading on that dosage?

  • To be honest I have no idea, my last blood test showed a TSH nearly 5 and my T3 was under range and T4 was near top of range but my GP reduced my dose a year ago and has been slowly raising it she was happy with my last results and left me on 50 day one 60 day two. I however was not happy so took it back to 60mcg a day, haven't been tested since 

  • Now they are very confusing results, especially as you had a high T4, high TSH and on a supressive dose of T3

  • Just dug out bloods 

    THS 4.98     0.34-5.60

    T3   3.1      3.8-6.00

    T4    2.9.     7.9-20.00

    Sorry I remembered wrong .....

  • so is that a 2.9 T4 or a 29?

  • 2.9

  • OK that makes much more sense in a way, the only strange thing is a high TSH.  So it shows your T3 meds is causing a T4 suppresion and that is why you felt better on a higher dose of T3 - But like me your still waking up hypo in a way although my T4 is below 1 with a TSH 0.01

    I think I am going to drop my T3 back to a daily of 25mcg and see if I can get my T4 up to a better level as this is when I was feeling better (over 10 years ago) 

    I cant tollerate T3 well and cant take T4 so I think its worth a try

    For you thats excellent that you do well on the T3 and you were wise increasing it up to a level that you fel better


  • Have you tried NDT? 

  • Yes I am totally intollerant to anything with T4, was VERY ill on NDT.  So my only option is T3 and ive tried for over 10 years.  So many docs telling me to up it but like galathea said it may be time to try the opposite

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