I normally take my NDT in two doses - early morning and afternoon. I am doing a finger prick blood test tomorrow morning. Would it be okay to take my last dose of NDT at around 8.30pm tonight and do the blood test at 8 am in the morning?
Also, is it really important that I don't eat until after the blood test, as i might find doing the finger prick test difficult if I'm really hungry, as I tend to go light-headed and feel shaky? Does eating before the blood test only affect the TSH and would this matter if you're on NDT?
Thank you.
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Rachel357
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Last dose of NDT should be 8-12 hours before the blood test, so taking your NDT at 8.30pm and doing your test at 8am is fine.
Eating can possibly affect TSH (as can coffee) but if that result isn't important then it's no problem if you have your breakfast. Eating doesn't affect any other result, it's only the timing of the last dose of thyroid hormone that affects results of FT4 and FT3.
Would there be a significant difference in the FT3 result depending on whether one takes their NDT all in one go the evening before the blood draw vs. dividing the dose, half in the morning and half in the evening before the blood draw (8-12 hours before blood test)?
That's exactly what I did yesterday and took one at 6am, second dose at 2.30pm I also took a third dose at 8.30pm. It's not an exact science, is it very hit and miss. Hoping for the best.
It's easy for people to say to leave of NDT for 10/12 hours before the test which is supposed to be first thing it's another to try and do it. I actually took a half extra grain at 8.30pm exactly what you are going to do. It cannot be right just hope. The thing is this if you are doing the blood test yourself and also self medicating it's hard. I did the same last year so that both can be compared to each other.
I took my last dose at 8.30pm and couldn't get to sleep until 4am. I then started to do the finger prick test at 7.50am and I could hardly get any blood out. I was there for about an hour and ended up pricking 6 fingers and still couldn't get enough blood. A few months ago when i did a finger prick test I had a shower first and I think that made the blood flow easily. I'm going to retake the test as soon as the bruises on my fingers have gone.
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