From the Research
Biotin supplements can significantly interfere with thyroid stimulating hormone (TSH) test results, and it is recommended to stop taking biotin at least 72 hours before blood collection to avoid inaccurate results. This interference occurs because many laboratory immunoassays use biotin-streptavidin binding as part of their detection method, and excess biotin in the blood sample can compete with the test's biotin-based components, leading to false results 1. The interference can affect not only TSH but also other hormone tests, including T4, T3, parathyroid hormone, and troponin.
Key Points to Consider
- Biotin is commonly found in hair, skin, and nail supplements, often at doses of 5,000-10,000 mcg, which is much higher than the recommended daily allowance of 30 mcg 2.
- The duration of biotin interference can last for several hours to days, depending on the dose and assay platform used 3.
- Some assay platforms, such as Abbott Architect 2000, may not be affected by biotin interference, while others, such as Roche cobas e602 and Beckman UniCel DxI 800, may be susceptible to interference 3.
- It is essential to inform healthcare providers about any supplements being taken before blood tests and to be aware of recent biotin exposure when interpreting thyroid test results 4, 5.
Clinical Implications
- Clinicians should be aware of the potential for biotin interference in thyroid function tests and take steps to minimize its impact, such as advising patients to stop taking biotin supplements before blood collection 1.
- In cases where biotin interference is suspected, alternative assay platforms or methods, such as liquid chromatography with tandem mass spectrometry (LC-MS/MS), may be used to confirm results 5.
- Patients taking biotin supplements should be closely monitored, and their thyroid function tests should be interpreted with caution to avoid misdiagnosis or inappropriate treatment 2, 4.