Thyroid UK
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Advice please

My latest results on 62.5 levo was:

Tsh 0.08 (0.35-5.5)

Ft4 12.9 (10-19.8)

Before on 75

Tsh was 0.05

Ft4 19.4

Same ref ranges.

Is it possible that 75 will bring up my ft4 enough again? I don't understand why it had dropped so much...

How long will it take before I start to feel better after an increase?

When I'm having my next blood test in 8 weeks I will order a private ft3 test to have a clearer picture of what's going on.

Thanks in advance!

5 Replies


75mcg daily will raise your FT4 but not necessarily back to 19.4 it was before your dose reduction.

It takes 7-10 days for Levothyroxine to be absorbed before it starts working and it will take up to six weeks to feel the full impact of the dose. Symptoms may lag behind good biochemistry by several months but you should be feeling gradual improvement during that time.

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Thanks! I hope it will resist it enough. I've been on 75 for a week but don't feel better. Do you know how come it dropped all the way down to 12.9?

When I started on 25 I had that number for ft4 so on 50 I had a higher number than on 62.5 seems strange to me.



It dropped because 62.5mcg wasn't enough but it is a surprisingly large drop in response to a very small 12.5mcg dose reduction.

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Just a random thought here - have you changed brand/pill dose or how/when you take the Levo?

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