Ratio of T4 to T3 medications? And how long to see benefits?

[Coppernob]

Is there a standard ratio of levothyroxine (T4) to triiothyronine (T3) dosages?

I've just been advised to reduce my daily dose of 75mcg T4 to 50mcg and add in 10mcg T3. Is that the standard?

Also, how long should you expect it to be after changing medication to see benefits? Thanks.

[shaws Administrator]

That ratio is fine. If you were on a higher dose of levo it would reduce by 50mcg.

Everyone is different in their response, so it's individual to each person.

[Tweetypie28]

Hi

Would you mind me asking why you are being prescribed T3, did you not feel well on T 4 only? It's just that I don't understand this t3/t4 stuff properly and I've not even ever had my T3 tested. Did you just have yours tested and then prescribed T3 or were you still having symptoms on T4 only that the doc just pescribed? Thank you

[Parbrook in reply to Tweetypie28]

There could be different reasons why people are on T3, so no single answer.

In my case, I was on T4 for 3 years before my GP agreed that my blood results showed that I was not converting T4 to T3, because my FT4 was high and my FT3 was low.

Now I am taking 75mcg Levothyroxine and 20mcg Liothyronine. Although I feel much better on this compared with T4 only, it feels like this is not the final answer, but have to wait for the next blood test before anything gets changed.

[Tweetypie28 in reply to Parbrook]

I see, thank you. I'm due my next appt with endo on Sat and she suggested adding T3 if I still didn't feel right. I sound like you, I would say I'm 80% better than ever but still not quite right! perhaps a touch of T3 might help me.

You sound like you have a decent switched on doc, lucky you! Hope you get sorted after next blood test so you can feel 100% again! x

[Parbrook in reply to Tweetypie28]

I have been lucky with my GP, because he has supported testing FT4 and FT3, as well as a trial of T3 (on condition that I agree to see an Endo).

I sense that I may have benefited from some positive discrimination, as my wife did not find him as helpful.

[puncturedbicycle]

Yes, that sounds good to me. Generally you read that 1mcg t3 = 5mcg t4 but in my experience it's not. When my doc put me on t3 I was not asked to reduce my t4 immediately.

Good luck! I had six really good months on t3 and even now that I'm not 100% it still keeps my oedema etc in check. It's just a matter of getting the balance right. x

[Parbrook]

I really started to notice an improvement after around 2 weeks when I reduced my T4 from 100 to 75mcg and increased T3 from 10 to 20mcg.

This included feeling warmer and better concentration.

[Clutter]

I felt improvement in brain fog in a matter of days when I added T3 to T4.

T3 also prevents the shortness of breath, racing heart, palpitations and tremors I experienced on T4 monotherapy.