Having a blood test. When do I take my Levo?

I now take my Levo about 10 o'clock at night and my blood test is scheduled for 9.15 in the morning. Should I take the dose the night before or wait until after the blood test?

PS I switched from morning to evening after reading all the advice and comments on this website and so far I am pleased that I did so big thanks to everyone.

11 Replies

Miss the night's dose and take after blood test.

Eek, I had a blood test today at 8am but took my dose last night, didn't realise. Will it make a big difference to the results??

It could make a difference.

Great - thanks very much

Good to hear the switch was good. We have seen a lot of positives - but, unfortunately, also some negatives.

Agree with shaws - that is what I do. And, on that one occasion, I do NOT worry about interference with breakfast, etc. :-)


Thanks - hopefully one day out of sync won't matter.

I have recently switched to bedtime levo too, but I don't think it makes a lot of difference to be honest ( yet)- considering I just used to throw it down my neck at some point in the day with all my other vitamins, I think I made the right decision and will stick with it.

How many hours should you leave between Levo and a blood test by the way? I too have a blood test tomorrow at 2.10 pm, should I not take my Levo tonight either?

I wouldn't. I think Helvella says too, that we should have our blood test first thing a.m. as the TSH is higher.

I didn't take it last night, so thanks for that, and have also not taken any of my other tabs or supps either. Would be great if I could choose my blood test time, but unfortunately I am in a rural area with oversubscribed surgery, so have to take what they give me and when they say!!!

Hope your results are good.

Hi The other thing that effects thyroid tests is Beta Blockers, never take in the morning before thyroid test.

Best wishes,


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