04/08/2026
Yes, Biotin may cause a false suppression (low) of the thyroid stimulating hormone (TSH) and in some cases it may even cause a false elevation of estradiol but this is only with doses over 5000mcg. There are some companies who have products with as much as 20,000mcg!!! Again, this is too much.
Hair care supplements and multivitamins with 1000-2000mcg are not shown to affect the labs and therefore they do not need to be stopped prior to labs.
Please educate yourself. Or better yet, do the labs with and without the appropriate amount of Biotin to prove it to yourself.
What I am concerned about more than biotin is providers not knowing that any thyroid medication with T3 (Armour, Np thyroid, Cytomel, Liothyronine) should be held until after morning labs as its half-life will most definitely reflect a lowered TSH resulting in patients either being lowered in their dose (because the TSH IS suppressed) or not increased in their dose when needed because the labs are “normal” but inaccurate. (Sat in a room over 500 providers when that was presented years ago while their mouths dropped).
Rant complete! (For now 😉)
XO, Tammy
