Thyroid UK
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TSH below range

Further to my recent blood results, my TSH is 0.24 (range 0.35-4.5) and Blue Horizon have noted that I may want to reduce my thyroxin which I am having trouble stabilising (after 8 years on 100).

I have just reduced my daily Levo - am now trying 4 x 87.5 and 3 x 100 (as per Clutter advice).

Do I need to worry about going hyper with a suppressed TSH ?

Could someone comment on how long this reduction will take to show in my blood tests ? I seem to notice in myself almost immediately whether I am becoming slightly over or slightly under medicated.

(I reduced it because around 2 weeks before blood test, I got insomnia worse and agitation during the day as well).

Am about to try NDT - is this a good time to change do you think ?



4 Replies

On its own, TSH has very little meaning, as it only shows the level of thyroid stimulating hormone and not how much thyroid hormone is available.

An FT4 test will indicate if you are on too much, or too little Levothyroxine.

You also need an FT3 test, which will show how well T4 is being converted to T3.


thankyou for reply.

FT4 was 20 (22 top of rangr)

FT3 was 5. (6.8 top of range)

so not at top but BH suggested poss overmedication.

not sure what to think



If you do not feel over-medicated, than you are probably OK.

Symptoms should have priority over blood levels.

I get hyper symptoms if my FT4 goes above 18.

To answer your question, a change in Levothyroxine dose can take up to 6 weeks to take full effect, although you should start to notice a change from 2 weeks.


Thank u


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