SupplementDuel

Biotin (B7)

Vitamin

Popularly marketed for hair, skin, and nails — but evidence only supports use if frankly deficient. Stop 3 days before any thyroid test.

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Typical dose
1000–10000 mcg daily
Evidence
Limited (small studies)
Onset time
Cumulative: 8–24 weeks
Half-life
~26 hours
Forms
Capsule, Tablet, Gummy
Source
microbial
Best taken with
with food
Best time of day
any
Bioavailability
5/5
Safety rating
5/5
Price per serving
$0.08
Vegan / GF / 3rd-party
✓ / ✓ / ✓
Find Biotin (B7)iHerb →

Vetted brands, third-party testing, ships worldwide.

Common uses

  • • Hair / nails / skin
  • • Biotin deficiency
  • • Brittle nails

Effect profile

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Common side effects

  • • Generally none
  • • Interferes with thyroid blood tests

Avoid if

  • • Thyroid testing scheduled

Drug interactions

  • • Antiseizure meds
  • • Lab assays

Related vitamin supplements

Biotin (B7) vs Vitamin D3Biotin (B7) vs Vitamin K2 (MK-7)Biotin (B7) vs Vitamin CBiotin (B7) vs Vitamin E (Mixed Tocopherols)Biotin (B7) vs Vitamin B12 (Methylcobalamin)Biotin (B7) vs Methylfolate (5-MTHF)

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements.