What time should I have blood test on NDT

[Abby77]

Hi, I can’t work out what time I should have my blood test. I am on armour and take it at 7am and between 3-5 pm.I know it should be after 12 hours but no longer than 17. My problem is that the blood clinic is only open from 9am-12 pm. What should I do?

[Angel_of_the_North]

I would delay my afternoon dose until 9pm and then get a test at 9am and take my 7am dose after the test.

[SeasideSusie Remembering]

The last dose of NDT or T3 should be 8-12 hours before blood draw, not after 12 hours or no longer than 17. This is because of the T3 element in NDT, T3 starts to leave the blood after 12 hours so gives a false low fT3 result.

[MaisieGray]

In effect, that's the 'wrong' question. 🙂 We don't adjust the time of the blood test to suit when we take thyroid meds, NDT or otherwise; we adjust the time we take the meds to fit with the need/benefit of having blood drawn as early in the phlebotomist's working day as possible.

As an aside, does your clinic not offer earlier appointments for those that are recognised as having to have non-fasting testing (generally TFT testing isn't recognised medically, as requiring fasting)? My local hospital's phlebotomy clinic sees the non-fasters from 9.00 onwards and the fasters during 7.00 - 9.00; and I always arrive well before 9.00 so I'm the first of that queue, and then if they run out of fasters, they start seeing the non-fasters early.