Research suggests that taking high doses of biotin may lead to inaccurate thyroid lab results. Stopping biotin several days before your test can help you avoid this. Biotin is a B-complex vitamin ...

Well, the answer isn’t so clear-cut. “Biotin is essential for hair and nail growth; biotin deficiency, in fact, can lead to hair loss and brittle nails,” says Carmen Castilla, MD, a board-certified ...

Our expert, award-winning staff selects the products we cover and rigorously researches and tests our top picks. If you buy through our links, we may get a commission. Taylor Leamey writes about ...