T3 and T4 question: On Christmas day I will be... - Thyroid UK

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T3 and T4 question

Nicola1964 profile image
9 Replies

On Christmas day I will be starting my T3 , I will cut the tablet in four, the question is I am on 150 eltroxin now should I decrease that dose when I start the T3. Thank you

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Nicola1964
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9 Replies
jimh111 profile image
jimh111

I would as your T3 will build up much quicker than fT4 falls due to the different half-lives. I would also skip a dose of levothyroxine when starting liothyronine, to get things to equal out more quickly. Liothyronine is about 3x as potent as levothyroxine, so 5 mcg lio is equivalent to 15 mcg levo. You could start on 10 mcg liothyronine as 5 mcg is very little, I would take a quarter tablet in the morning and a quarter at bedtime.

Nicola1964 profile image
Nicola1964 in reply to jimh111

Thank you Jimh111. How much do you think I should reduce 25mcg eltroxin?

jimh111 profile image
jimh111 in reply to Nicola1964

Replace 25 mcg Eltroxin with 10 mcg liothyronine. Since levothyroxine has a seven day half-life and liothyronine 24 hours I would skip your levothyroxine for one day and resume on 25 mcg less whilst starting on the liothyroxnine. This will even out the changeover a little. If you start on 5 mcg liothyronine maybe take 25 mcg less levothyroxine every other day.

Nicola1964 profile image
Nicola1964

That's great Jimh111 thanks so much for your time..

Goinginsane1 profile image
Goinginsane1

how did you manage to get prescribed t3?

Nicola1964 profile image
Nicola1964

I didn't goinginsane1, I am self medicating, being dealing with clueless doc 23 years now and I am not putting myself through anymore with them.

TiggerMe profile image
TiggerMe

It depends on how near to the top of range your fT4 result is... if close to top then a small decrease might be good but if 80% or lower then I wouldn't as taking T3 will likely make it drop off anyway 🤗

SarahJane1471 profile image
SarahJane1471

I agree with TiggerMe . I would only change one thing at a time. I didn’t reduce my Levo when I introduced Lio. My FT4 was about 75% in range. I only need a tiny bit of Lio morning and early afternoon (2x3mcg). It’s a very individual thing.

When I did try reducing Levo about 6 months into taking Lio I felt rubbish. There are two schools of opinion on this forum about this. Neither one is “wrong” and either one is “right”. That seems unhelpful I know but because it’s such an individual thing it’s about trial and error.

Nicola1964 profile image
Nicola1964

Thank you SarahJane1471, I am actually feeling good also despite being hit with flu all week and I don't want messing with that. So I will go with that one change at a time. Thank you👍

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