Thyroid UK
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On T3 but had no blood tests

Hi, I have been on 50mcg Levo and 20mcg since February when it was upped by my Endo, I started on combo last November 75 Levo 10mcg T3 but I have never had a blood test for T3 only TSH and T4 I'm not due to see Endo till May 10th I feel a lot more alert than I did but I seem to be getting odd highs more anxiety and feel hot then I go to feeling weary again could this be antibody attacks causing this? I was diagnosed in November 2015 high antibodies which my Endo has never mentioned he never tested me it was done by another hospital. This Endo doesn't want my GP doing any bloods in between seeing him. So I've gone 5 months taking T3 and no blood tests. I feel much better with the brain fog and I'm up and about more but I'm now having these odd times of anxious and hot flare ups then feeling so weary. Not the menopause that's well gone! The endo only upped my T3 in Feb this year as I was having afternoon slumps I'm just bit concerned I haven't had a blood test for T3 since taking it.can anyway advise Please!

9 Replies


Do you split your T3 doses? If not it could be low T3 in the afternoons causing your 'slumps', and high T3 in the mornings causing your 'anxious & hot flare ups'.

It may be useful to take 10mcg in the morning (5am ish) with your T4, then 5mcg around 11pm/12pm, and another 5mcg around 5pm/8pm (or before bed). But you will have to see if it helps & play around with the doses & timings to get exactly what works for you.

Hope this is helpful

1 like

Thank you for your reply Endo said take 10mcg athe 7am and 10 again at 12 midday it was OK the first few weeks I felt great now it's highs and lows with horrid anxious flare ups then lethargy I'm on a break in Weymouth walking with my dogs so it's spoiling it took to a day of sleep yesterday not done that for ages....


T3 has quite a short half life (4-12 hours depending on the person), so you may feel better splitting it down a bit more.

When do you feel anxious, & when do you feel lethargic? Are there particular times?


The flare ups are not in the mornings always pm onwards when they happen



It could be that if you split the 12pm 10mcg dose into 2x5mcg & take 5mcg at 12pm then the other 5mcg later in the day, it would even things out a bit.

& if you are lower in the am, you may need slightly more at 7am.

Or you could attempt an earlier dose in the am to help your adrenals function (it can make the morning dose more potent, so you dont need to up the dose, but have the effect of a higher dose). E.g. take the 10mcg at 4-5am then go back to sleep for a few hours.

The main thing is to alter things slowly & monitor how you feel.


Makes sense to me Thank You! I'll give that a go not having any t3 bloods tests at all in the 5mths I've been on them on thought a bit strange.. well let's see how I go Thank goodness for this forum


Let us know how it goes. Good Luck!!



You can order your own FT3 test via


Clutter i think I'll have to if Endo doesnt


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