What does it feel like for you when T3 runs low?

Hi, I have quite a bit going on with my health and disentangling hypothyroid symptoms from other issues is difficult as it is so long since I felt fully well.

I have been trying different ways of splitting my 15mcg T3 ( plus 75LT4) I can't work out the relationship between dose timings and how I feel.

Can anyone tell me please how they feel/symptoms if they leave it too long before their next T3 dose?


12 Replies

  • I feel almost like I've been sedated, and my ankles swell.

  • I take mine once a day. Clemmie

  • I take 25mcg twice a day and start to get a headache if I'm overdue my second dose

  • If I'm overdue for a dose the first thing to happen is I get a very fast heart rate (about 120+) and if I still don't take any meds I become soooooo tired and weak I feel as if I've been sedated, just like shaws. (Very good choice of word, shaws. :) )

  • The comment was by Puncturedbiicycle :) and it is a descriptive word I would also use.

  • I knew I needed my eyes testing! Sorry puncturedbicycle !


  • No worries. :-)

    When people say that hypothyroidism makes you feel 'tired' I always think, hmm, everyone feels tired but not everyone feels like they've been given a sedative, which is how I feel when undermedicated, and specifically when I was taking a split dose of t3 and the next was overdue.

  • I'm wondering if in my case T3 running out is responsible for my "thudding" but not racing heart. Numb, tingly hands and an "on edge" jittery feeling. I can't tell if I'm tired or "like sedated" because my sleep has been so bad that I'm having daytime bed breaks anyway. My morning basal temps are 36.2 - 36.3 oral and 0.3 or so higher rectal. I think I'm under-medicated, but I reduced T3 from 20 to 15mcg because I was getting a thudding heart all day long. Endo appt next Friday - not feeling hopeful there as TSH and FT4 just below range with T3 5.3 ( this was 17 hours after last 10mcg dose (twice a day ))

  • Palpitations can affect me when I'm short of T3 too.

    It is possible to cut T3 into quarters. I use a scalpel or hobby knife rather than a pill cutter. Perhaps you could try smaller doses but more of them?

  • This may be helpful if you've not seen it before. It was by a scientist/doctor who took 150mcg once daily (in the middle of the night).


  • .... a mild increase in heart rate or "force of contraction" I guess that's technical speak for "thudding" :-)

    I've just had a good day and a very bad night after a single morning dose of 15mcg T3.

    Gonna stay on same regimen until after endo on Friday. Will show him DI02 hetero gene test result, expect him to be unimpressed and will then make decision to how to proceed. Defo need more of something, but v.slightly below range TSH is not in agreement and that will likely determine endos action plan:-(

  • I feel like I'm walking through custard. 😏X

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