Thyroid UK
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Cortisol blood test - leave T4 dose out?

I have my cortisol blood test in the morning ( 9am) as requested by the endo prior to deciding if they will see me (I suspect will say it's fine so will get out of doing a T3 test...grrr).

I take my levo at bedtime ( about midnight) so should I not take it tonight? I know people have said on here not to take meds prior to blood tests but wondered if 8 hours is enough?

Thanks in advance.

3 Replies

I would skip it purely for the reason that they may decide to also test your thyroid 'while you are there'


No, they don't want to do that,as it hasn't been 6 weeks on the increased levo yet, I have that booked in for 2 weeks time ( the good old TSH test... :() so tomorrow is just a blood cortisol test at the request of the unseen endo....hmmm.


Levo does not interfere with the cortisol test, however still make sure they won't do the thyroid function, I have heard it a million times that they don't plan to do them then they still do!


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