T3 and T4 question

[Nicola1964]

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

[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 in reply to jimh111]

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

[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]

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

[Goinginsane1]

how did you manage to get prescribed t3?

[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 Ambassador]

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]

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]

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👍