Thyroid UK

Iron and blood tests

Hi, I am on levothyroxine75 mg as I had my pituitary removed 17 yrs ago and have managed quite well until recently. I think from my symptoms I may be hypo but at my last endo apt the consultant only measured my free T4 and TSH , my TSH was obviously non existent and the FreeT4 was sat nicely in the mid range.

She was a very nice doctor, spent a good 5 mins telling me all about her mums recent illness and another 5 in how she was trying to become a GP. My proper consultation about 1 min extended to comments that my skin was dry and I looked puffy. Not quite sure where to go from here, I am thinking of going to my GP and asking him to do the T3 etc or send away privately. I am taking iron at the moment for low ferritin (11 )and iron (9 ), both below normal range. Do I need to stop this before testing?



2 Replies

Hi Ratkinson,

Most people will be comfortable with FT4 in the upper quadrant of range. Ask you GP to increase dose reminding him/her that it's useless to test your TSH. You can certainly ask your GP to test FT3 but s/he may not be able to do so as a lot of primary care no longer tests FT3 but it's possible the lab will be concerned about non-existent TSH and will automatically test FT3 to rule out hyperthyroidism. If not, you can order private thyroid tests from Blue Horizon and Genova via

Don't take Levothyroxine dose until after your blood draw but there's no need to stop supplementing iron as iron won't impact on your thyroid test. Remember to take iron 4 hours away from Levothyroxine.


Thanks for your reply, much appreciated



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