Thyroid UK

Help with blood results

Hi, I have been taking carbinzole for a number of years now. I have suffered at various times with extreme hyperthyroidism symptoms but this last year things have got a little better. I had been taking a daily dose of 15mg of Carbinzole for a few months and my reading were Tsh 4.3 so my GP reduced to 10 mg per day. After a few months I became hyper again so the dose went back to 15 mg daily. Tsh elevated to 4.3 so my dose was revised again to 15 mg and 10 mg on alternative days which give the levels of Tsh 2.7. This was Oct 2017' I remained on the same dosage and have just has a blood test 8th Jan 2018 and my levels are Tsh 1.68 T4 9.6. My GP has advised me to decrease the carbinzole dose to 10mg per day and I am now concerned that I will become hyper again. I did question this decision but was told this was the right thing to do. I am due another blood test in 6weeks. Can anyone advise if I should be feeling concerned or just do what I'm instructed by the GP and see what happens.. Many thanks.

8 Replies


I would follow your GP's advice. GP has been managing your thyroid levels well until now. If your FT4 rises too much it will be picked up on your next blood test and dose can be increased.


Clutter,thank you so much for the speedy response. I'm just terrified of reliving the terrible time I had 18 months ago when I lost over 2stone in weight along with all the other horrible symptoms. It took me over a year before I felt semi normal again. Incidentally, I am never advised to fast or to stop the medication for the blood test,is this correct?


I had all my tests done around 9am, before taking that day's Carbimazole and before breakfast. However you do it, try and keep it the same each time.



If you feel you are becoming hyperthyroid don't wait 6 weeks ask for a thyroid test sooner.

Advice to fast and take meds after blood test is for hypothyroid patients on Levothyroxine. It's not applicable to hyperthyroid patients taking Carbimazole.

1 like

If you are that concerned why dont you ask to drop to 12.5mg of Carbimazole? All you have to do is cut a 5mg tablet in half.


Silver Fairy I was taking 12.5 mg up until today and my levels were dropping. My GP has instructed me to decrease the dosage to 10mg daily despite this,saying it's the right thing to do. That's why I'm concerned. I'll abide by his instructions and as Clutter advised if the symptoms return I'll go back to my doctor. It's so good to hear from others who understand this horrible condition so thank you all for the great information and advice,its very much appreciated😘


Sorry, missed that - you were taking 10mg & 15mg alternate days.


Hi i am just like you at the moment i have been on carbi for 6 months now and started off on a 20mg dose then a 10mg, then 7.5mg and then recentley 5mgs and now for the last week 2.5 mgs my levels are now hypo as my endo wanted me on 10mgs for too long and still wanted me to take 5mgs still but my tsh is 5.48 and frees were dropping, i think youre endo is doing a good job at monitoring you, i was just left to get on with it. I know how you feel with being hyper and you want to stay on a higher dose but you will hit hypo levels, it is hell on earth being hyper but being hypo is just as bad. 2 hells on earth.

As the others have said get yourself a blood test dont wait and then you will be able to see what to do. Im due new bloods this week and i know that they are going to be more hypo.. good luck.


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