Biotin n blood test

Hi can I just ask n confirm I'm right in leaving off my B complex a week before thyroid blood test as it has 300ug biotin which I took 2 times a day I have been on this b complex for 2 years nearly so I'm hoping the biotin is out of my system and I'm getting correct results

[SlowDragon Administrator]

Yes correct

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results

endo.confex.com/endo/2016en...

endocrinenews.endocrine.org...

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

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

If/when also on T3, make sure to take last third or quarter of daily dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test

Is this how you do your tests?

[Hidden in reply to SlowDragon]

I didnt realise it interferes with ferritin results as well

[SlowDragon Administrator in reply to Hidden]

Biotin can interfere with wide range of tests....it’s apparently used in many lab tests

[Hidden in reply to SlowDragon]

Is 300ug twice a day too much ? So it's just from supplements not biotin in food eggs etc

[SlowDragon Administrator in reply to Hidden]

Just supplements