Getting first blood test since starting levo - Thyroid UK

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Getting first blood test since starting levo

mia33 profile image
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Hi I just wanted to check if its necessary to have the blood test before taking the first levo tablet of the day? I usually take mine on rising around 7am but if I wait until after my blood test it'll be about 10am. I'm concerned this may trigger a migraine, which I seem to be getting many of :(.....

Which brings me to another question if I may... I have been getting many more migraines since becoming hypothyroid (I guess?) and I wonder if they will start becoming less frequent as the hormones re-balance?

Many thanks

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mia33
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SeasideSusie profile image
SeasideSusieRemembering

mia33 It's important to leave 24 hours between your last dose of Levo and the blood draw. Also make sure you fast overnight although you can have water.

The reason for this is because doing so will give you the highest possible TSH and that is important when looking for an increase in dose or to avoid a reduction. Doctors only tend to go by TSH and you could miss out on a vital increase in dose, particularly as you are only just diagnosed and it's your first re-test.

It's a patient to patient tip which we don't discuss with doctors or phlebotomists.

shaws profile image
shawsAdministrator

Levo has a very long half life so I don't think taking it after the blood test will affect you.

One dose of T4 taken today takes about 4 to 5 weeks to leave your system.

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