From the Research
Biotin does not directly affect warfarin levels or its anticoagulant activity, but high-dose biotin supplements can interfere with laboratory tests used to monitor warfarin therapy. Patients taking warfarin can generally take biotin supplements without concerns about drug interactions affecting their INR (International Normalized Ratio) or increasing bleeding risk. However, biotin can interfere with certain laboratory tests, including those used to monitor warfarin therapy, by disrupting the biotin-streptavidin binding used in many laboratory assays 1. High-dose biotin supplements (typically over 5 mg daily) can cause falsely elevated or decreased results in lab tests that use biotin-based technology, potentially leading to incorrect dosing decisions for warfarin.
If you take biotin supplements and are on warfarin therapy, inform your healthcare provider about all supplements you're taking, and consider stopping biotin for at least 72 hours before scheduled blood tests to monitor your warfarin therapy, as suggested by recent guidance on biotin interference in laboratory tests 2. This precaution helps ensure accurate test results and appropriate warfarin dosing. The most recent and highest quality study on biotin interference in laboratory tests, published in 2020, provides guidance on preventing, identifying, and dealing with biotin interference 1.
Some key points to consider:
- Biotin supplements do not affect the actual anticoagulant effect of warfarin in the body.
- High-dose biotin supplements can interfere with laboratory tests used to monitor warfarin therapy.
- Informing healthcare providers about biotin supplement use and considering stopping biotin before blood tests can help ensure accurate test results and appropriate warfarin dosing.
- Recent studies and guidance documents emphasize the importance of being mindful of biotin interference in laboratory tests, particularly for patients taking warfarin therapy 1, 2.