Advice on percentages in reference ranges

[Handsome14]

Evening, can anyone explain about percentages and whether I should be aiming for 1OO% in both T4 and T3

I've posted before so hoping I don't need to include all my details. Thanks 🙏

[greygoose]

What you need to aim for is feeling well. Blood tests, ranges, results and percentages are just a rough guide to tell you if you're on the right track, but it's how you feel that is important.

So, that's why, with hormones, we start on a low dose and increase slowly, until the symptoms are gone and you feel well. Then, that point in the range is where you need to be. And, it will be different for everyone, because we all have individual needs.

However, as a general rule, most hypos need their FT4 up in the top third or quarter of the range, with their FT3 just slightly lower.

[Lalatoot]

No it is not like a maths test where you want to get 100%. You need to get to a level where you feel well within the range whatever that percentage is.The range is like a list of normal sizes. You need to find which size fits you.

Don't get hung up on percentages - they are only a way of comparing results.

[SeasideSusie Remembering]

100% is too high.

It depends where you feel well and that is very individual. I seem to be optimally medicated with my FT4 at about 65% and my FT3 a little bit higher, about 75%. But my levels won't suit everyone.

[humanbean]

100% for either Free T4 and Free T3 would be too much for most people. There are some rare people who need over-range Free T3 but if that is the case they often need little or no Free T4.

I haven't come across anyone saying that they need over range Free T4 in order to feel well, but that isn't the same as saying such people don't exist.

As a very general rule of thumb most people prefer Free T4 to be 60% - 80% of the way through the range, and for Free T3 to be 50% - 70% of the way through the range. This is assuming that someone is on Levo only or Levo + T3.

Results will be different for people on NDT only or on T3 only.

But none of the things I've written can be called "rules". They are just guidelines as to what works for many of the people who come here and say they feel well.

[Handsome14 in reply to humanbean]

Big thanks to you all for your helpful replies