VitaminNo.008
Biotin (B7)
Hair, skin & nails (marketed); energy metabolism.
Typical / RDA30 mcg
Upper limitNone set
EvidenceLimited
How to take it
Timing AnytimeFood OptionalForm High-dose pills common
What to know
Deficiency is rare, and hair/nail benefits only appear in people who are actually deficient. Notably, high-dose biotin can distort lab tests (thyroid, troponin).
Interactions & cautions
- Can cause false lab results — tell your doctor before blood tests.
Do you actually need it?
Rarely needed; stop several days before bloodwork.
Questions people ask about biotin (b7)
- Does Biotin Really Help with Brittle Nails?Biotin may help brittle nails, but typically only if you have a rare deficiency. For most, the evidence is limited, and high doses can interfere with lab tests.
- Do you need separate biotin if you take a B-complex supplement?Most B-complex supplements already include biotin. Taking a separate biotin pill is generally redundant and rarely needed, as the recommended daily intake is 30 mcg, typically met by diet or a B-complex.
- Which supplements actually help with hair thinning and breakage?For hair thinning and breakage, biotin, collagen, zinc, and selenium are often marketed. Only zinc and selenium have moderate evidence, mainly for deficiencies.
Reference values: NIH Office of Dietary Supplements, adult general population. Educational information only — not medical advice. Confirm with a healthcare professional.