Deficiency is rare. Its real problem is that it corrupts blood test results.
What the evidence supports: correcting deficiency; hair and nail claims lack support in non-deficient people.
This scores how well-supported the claim above is — not how much benefit you personally would get. A high score on a narrow claim does not extend to everything the product is marketed for.
Short courses. Evidence for hair and nail benefit in people who aren't deficient is weak.
Documented deficiency, and some pregnancy-related needs.
Other supplements:
Run your full list through the interaction check.