Hair, skin & nails evidence brief
Biotin is a B vitamin commonly used for hair, skin, and nail health. It matters most when deficiency or a related medical context is present.
Biotin can help when deficiency or a related disorder is present, but routine beauty claims for healthy users are poorly supported.
2017 review: published improvement cases were tied to underlying pathology or deficiency; strong evidence in healthy users was lacking.
Correcting deficiency is a clinical nutrition issue. High-dose cosmetic use should be avoided before lab testing unless disclosed to clinicians.
Biotin can interfere with some lab tests, including hormone and cardiac-marker assays, so users should tell clinicians before blood work.
Source Drawer
The score reflects evidence that the supplement does its stated job. Some jobs are direct, such as strength, endurance, or recovery; others are indirect, such as sleep, mood, appetite, or health support. A real effect can still receive a cautious practical rating when dose, safety, product quality, or audience fit remain uncertain.
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