blood test

[Disey]

I have a blood test booked for 4pm tomorrow, I take 25mg levothyroxine in the morning and 25mg at night, could you advise me when should I take my tablets to get the best result from the 4 pm booking tomorrow? Many thanks

[SlowDragon Administrator]

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Testing in afternoon will significantly lower TSH making it much harder to get dose increase in levothyroxine

So suggest you rebook an early morning test

With your nightime dose ...adjust timings as follows prior to blood test

If testing Monday morning, delay Saturday evening dose levothyroxine until Sunday morning. Delay Sunday evening dose levothyroxine until after blood test on Monday morning. Take Monday evening dose levothyroxine as per normal

[Disey in reply to SlowDragon]

Thanks so much for your advice, I’ve rebooked for sat morning. The doctor has actually agreed to test ft3, never been tested before so I’m quite shocked to be honest

[SlowDragon Administrator in reply to Disey]

You also need folate, ferritin and B12 tested annually

Vitamin D twice year

And TPO and TG thyroid antibodies at least once

[Disey in reply to SlowDragon]

I’ve not long had them all done, this is just because of trying a slow increase, this time I’m having vit d, ft3, ft4 tsh, bone profile but the others you mentioned I had roughly bout 2-3 months ago