falsely low TSH and biotin

Last edited 10/2023 and last reviewed 10/2023

TSH may be falsely low in patients who take supplemental biotin, as biotin can interfere with some immunoassay platforms (1)

  • enquire about biotin use at the time of testing in patients with convincing signs or symptoms of hypothyroidism and a normal TSH, and ask patients to stop biotin supplements for several days before thyroid function testing

NICE note:

  • ask adults, children and young people with suspected thyroid dysfunction about their biotin intake because a high consumption of biotin from dietary supplements may lead to falsely high or low test results.

Reference: