From the FDA Drug Label
Biotin levels higher than the recommended daily allowance may cause interference with some laboratory tests, including cardiovascular diagnostic tests (e. g. troponin) and hormone tests, and may lead to incorrect test results.
- Biotin can interfere with some laboratory tests, including hormone tests.
- This interference may lead to incorrect test results, which could potentially affect thyroid-stimulating hormone (TSH) test results.
- Therefore, biotin may throw off TSH test results if taken in high levels 1.
From the Research
Yes, biotin supplements can interfere with thyroid stimulating hormone (TSH) test results, causing falsely low TSH readings in commonly used laboratory tests, potentially leading to misdiagnosis of thyroid conditions. This interference occurs because many lab tests use biotin-based technology, and excess biotin in the blood can disrupt the testing mechanism. The effect is dose-dependent, with higher biotin doses (typically 5 mg or more daily) more likely to cause significant interference, as seen in a study where a daily dose of 10 mg was shown to interfere with specific assays for TSH, fT4, TT3, and Tg 2.
Key Points to Consider
- Biotin can cause falsely low TSH readings, potentially leading to misdiagnosis of thyroid conditions 3.
- The effect of biotin on TSH test results is dose-dependent, with higher biotin doses more likely to cause significant interference 4.
- If you're taking biotin supplements and need thyroid testing, you should stop taking biotin for at least 2-3 days before blood tests, though some experts recommend discontinuing for up to 7 days for higher doses 5.
- Always inform your healthcare provider about any supplements you're taking, including biotin, before thyroid testing to ensure accurate results and proper interpretation of your thyroid function 6.
Recommendations for Clinical Practice
- Be aware of the potential risk of erroneous test results in subjects taking biotin supplements 2.
- Consider the possibility of biotin interference in patients with abnormal thyroid function test results, especially if they are taking high doses of biotin 3.
- Inform patients about the potential interference of biotin with thyroid function tests and advise them to stop taking biotin supplements before blood tests if necessary 5.